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#1
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle withload present?
How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car?
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#2
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 2019-06-21 1:19 p.m., Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to switch to trickle charge?* I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? the catalytic converter tells it |
#4
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle with load present?
Commander Kinsey wrote
How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. |
#5
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On Fri, 21 Jun 2019 21:54:38 +0100, Rod Speed wrote:
Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. But how can the regulator on the alternator possibly know the current it's passing to the battery is going into the battery and not going straight across to the lights? If you look at the battery in your car, there are two or three thick wires coming off each terminal. One will go to the alternator, another to the fusebox for all the lights etc. Unless there's some clever circuitry monitoring each battery wire individually and subtracting the currents, the alternator can't tell the difference between a battery taking 12 amps, and a battery taking 2 amps plus lights taking 10 amps. The second one requires switching to trickle charge, the first doesn't. |
#6
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 06:54:38 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. Does the unwashed Scottish ******'s taste THAT good, senile Rodent? He'll certainly climax soon with your help, senile Ozzie cretin! LOL -- about senile Rot Speed: "This is like having a conversation with someone with brain damage." MID: |
#7
Posted to alt.home.repair,uk.d-i-y,alt.electronics,uk.rec.driving
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On Fri, 21 Jun 2019 22:18:56 +0100, trader_4 wrote:
On Friday, June 21, 2019 at 4:54:51 PM UTC-4, Rod Speed wrote: Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. Except that the alternator doesn't know how much current is going into the battery and how much is being used to power the car. At least not in any car I've had. The alternator is tied directly to the battery and that common point supplies the car. The alternator can't switch to trickle charge either. Every one I've seen, with the car running normally, the voltage at the alternator/battery is about 13.5 - 14V I used to think the same, until someone in one of these newsgroups (on another topic about 6 months ago) said it drops the voltage or it would wear out the battery on long journeys. I tested my own car, by leaving the lights on for a bit, then starting it. The voltage was about 14.4. It dropped to 13.8 after the battery was filled up. The regulator must have detected the battery was full somehow and lowered the charging voltage. Mind you after some googling, apparently a lead acid is happy being charged from 13.8 to 14.5 continuously. Although when I used to leave my car on a charger (an old Bradex car battery charger) at 14.5, it ****ed the battery after a few months. Maybe 14.5 is only ok in a car alternator circuit, which isn't usually running 24 hours a day. I think I'll always make sure it's 13.8 if it's on charge all the time - my car tends to randomly lose battery power overnight (to the alarm I believe). I was just wondering if I bought an intelligent car battery charger, whether it would ever switch down to trickle if the alarm was sucking juice, as such a charger may not expect any load. I currently have it connected to a bench supply at 13.8. |
#8
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to switch to trickle charge?* I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. -- Max Demian |
#9
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Troll-feeding Senile IDIOT Alert!
On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian, another brain dead,
troll-feeding senile asshole, blathered: The voltage perhaps. What kind of a troll-feeding asshole are YOU? |
#10
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote:
On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's determined by the alternator or charger. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly. It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? |
#11
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 21:54:38 +0100, Rod Speed wrote: Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. But how can the regulator on the alternator possibly know the current it's passing to the battery is going into the battery and not going straight across to the lights? The computer knows whats going to the battery and you can see that with an ODB2 dongle. If you look at the battery in your car, there are two or three thick wires coming off each terminal. One will go to the alternator, another to the fusebox for all the lights etc. And it's the voltage across the one going from the alternator to the battery that allows the computer to know how much current is going to the battery. Unless there's some clever circuitry monitoring each battery wire individually and subtracting the currents, Yes there is, its called the computer. the alternator can't tell the difference between a battery taking 12 amps, and a battery taking 2 amps plus lights taking 10 amps. But the computer can. And knows if the lights are on too. The second one requires switching to trickle charge, the first doesn't. |
#12
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On Fri, 21 Jun 2019 23:39:34 +0100, Rod Speed wrote:
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 21:54:38 +0100, Rod Speed wrote: Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. But how can the regulator on the alternator possibly know the current it's passing to the battery is going into the battery and not going straight across to the lights? The computer knows whats going to the battery and you can see that with an ODB2 dongle. My dongle only lists faults. If you look at the battery in your car, there are two or three thick wires coming off each terminal. One will go to the alternator, another to the fusebox for all the lights etc. And it's the voltage across the one going from the alternator to the battery that allows the computer to know how much current is going to the battery. Bull****. How could it possibly know if the current flows into the battery or goes to the other wire leading to the fusebox? Unless there's some clever circuitry monitoring each battery wire individually and subtracting the currents, Yes there is, its called the computer. So what happened with older cars before they did that? the alternator can't tell the difference between a battery taking 12 amps, and a battery taking 2 amps plus lights taking 10 amps. But the computer can. And knows if the lights are on too. The second one requires switching to trickle charge, the first doesn't. |
#13
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 08:39:34 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: The computer knows The troll knows how to bait all you senile assholes successfully, senile asshole! -- Sqwertz to Rot Speed: "This is just a hunch, but I'm betting you're kinda an argumentative asshole. MID: |
#14
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly. It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. |
#15
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 08:57:52 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: That's the way batterys work That's the way how your and his trolling work, you senile asshole troll! -- Bod addressing senile Rot: "Rod, you have a sick twisted mind. I suggest you stop your mindless and totally irresponsible talk. Your mouth could get you into a lot of trouble." Message-ID: |
#16
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:39:34 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 21:54:38 +0100, Rod Speed wrote: Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. But how can the regulator on the alternator possibly know the current it's passing to the battery is going into the battery and not going straight across to the lights? The computer knows whats going to the battery and you can see that with an ODB2 dongle. My dongle only lists faults. Because it's a steaming turd with wheels frog car. Most show all sorts of things. If you look at the battery in your car, there are two or three thick wires coming off each terminal. One will go to the alternator, another to the fusebox for all the lights etc. And it's the voltage across the one going from the alternator to the battery that allows the computer to know how much current is going to the battery. Bull****. We'll see... How could it possibly know if the current flows into the battery or goes to the other wire leading to the fusebox? By measuring the voltage drop across those cables, stupid. Unless there's some clever circuitry monitoring each battery wire individually and subtracting the currents, Yes there is, its called the computer. So what happened with older cars before they did that? The voltage across the battery changes as the battery is charged. the alternator can't tell the difference between a battery taking 12 amps, and a battery taking 2 amps plus lights taking 10 amps. But the computer can. And knows if the lights are on too. The second one requires switching to trickle charge, the first doesn't. |
#17
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote:
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Yip. I can put any voltage I like across a battery's terminals. The battery then chooses how much current is drawn. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly. It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. For example, I'm currently keeping my car's battery topped up with a bench supply overnight. It's set to 13.8V, with a current limiter only to prevent overloading the supply. The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A. The only way I or the supply can tell the battery is full, is by the current dropping to 100mA. But it's actually always full, as when 4A is drawn, that's going to a load. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. I guess that may be true, if the car's computer has two ammeters and subtracts one from the other. But AFAIK, the alternator regulator only works by it's own current sensor. And that current could be going into the battery, or past it to the loads. |
#18
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On Sat, 22 Jun 2019 00:26:13 +0100, Rod Speed wrote:
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:39:34 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 21:54:38 +0100, Rod Speed wrote: Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. But how can the regulator on the alternator possibly know the current it's passing to the battery is going into the battery and not going straight across to the lights? The computer knows whats going to the battery and you can see that with an ODB2 dongle. My dongle only lists faults. Because it's a steaming turd with wheels frog car. Which should adhere to the ****ing OBD standards according to the frog's own EU regs!! And a very basic OBD reader I bought to determine why a warning light was on. Most show all sorts of things. If you look at the battery in your car, there are two or three thick wires coming off each terminal. One will go to the alternator, another to the fusebox for all the lights etc. And it's the voltage across the one going from the alternator to the battery that allows the computer to know how much current is going to the battery. Bull****. We'll see... How could it possibly know if the current flows into the battery or goes to the other wire leading to the fusebox? By measuring the voltage drop across those cables, stupid. Unless there's some clever circuitry monitoring each battery wire individually and subtracting the currents, Yes there is, its called the computer. So what happened with older cars before they did that? The voltage across the battery changes as the battery is charged. Wrong. Say the alternator can produce 14V at up to 50 amps. When the battery has been used to start the car and perhaps run some lights when the engine was off, it takes maybe 25A, and the voltage is 14V, regulated by the alternator's circuitry. When the battery becomes full, it takes only a fraction of an amp, but the voltage is still 14V. What needs to be measured is the current going into the battery, and that cannot be done by just measuring the current coming from the alternator, as that could also be going to lights, heaters, spark plugs, etc, etc. the alternator can't tell the difference between a battery taking 12 amps, and a battery taking 2 amps plus lights taking 10 amps. But the computer can. And knows if the lights are on too. The second one requires switching to trickle charge, the first doesn't. |
#19
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 09:26:13 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: FLUSH the two clinically insane asshole's latest troll**** unread -- Richard addressing Rot Speed: "**** you're thick/pathetic excuse for a troll." MID: |
#20
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Yip. Nope. I can put any voltage I like across a battery's terminals. Nope. The battery then chooses how much current is drawn. And that current changes depending on the how charged the battery is. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly. It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. For example, I'm currently keeping my car's battery topped up with a bench supply overnight. It's set to 13.8V, with a current limiter only to prevent overloading the supply. It actually specify the current being supplied. The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A. The only way I or the supply can tell the battery is full, is by the current dropping to 100mA. But it's actually always full, as when 4A is drawn, that's going to a load. What load ? There no load with a battery being charged with a bench supply. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. I guess that may be true, if the car's computer has two ammeters It has more than one wire to the positive terminal of the battery. So it can see what current is going to the rest of the car. and subtracts one from the other. But AFAIK, the alternator regulator only works by it's own current sensor. And that current could be going into the battery, or past it to the loads. Not when there is more than one wire going to the positive terminal of the battery, and there always is. |
#21
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Commander Kinsey" wrote in message news On Sat, 22 Jun 2019 00:26:13 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:39:34 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 21:54:38 +0100, Rod Speed wrote: Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. But how can the regulator on the alternator possibly know the current it's passing to the battery is going into the battery and not going straight across to the lights? The computer knows whats going to the battery and you can see that with an ODB2 dongle. My dongle only lists faults. Because it's a steaming turd with wheels frog car. Which should adhere to the ****ing OBD standards according to the frog's own EU regs!! Steaming turd frog cars don't work like that. And a very basic OBD reader I bought to determine why a warning light was on. Should still show that other stuff. Most show all sorts of things. If you look at the battery in your car, there are two or three thick wires coming off each terminal. One will go to the alternator, another to the fusebox for all the lights etc. And it's the voltage across the one going from the alternator to the battery that allows the computer to know how much current is going to the battery. Bull****. We'll see... How could it possibly know if the current flows into the battery or goes to the other wire leading to the fusebox? By measuring the voltage drop across those cables, stupid. Unless there's some clever circuitry monitoring each battery wire individually and subtracting the currents, Yes there is, its called the computer. So what happened with older cars before they did that? The voltage across the battery changes as the battery is charged. Wrong. Nope, Say the alternator can produce 14V at up to 50 amps. When the battery has been used to start the car and perhaps run some lights when the engine was off, it takes maybe 25A, and the voltage is 14V, Yes. regulated by the alternator's circuitry. Nope, buy the battery, and you can prove that with the bench supply. When the battery becomes full, it takes only a fraction of an amp, Yep, because the battery voltage has risen. but the voltage is still 14V. Nope, and you previously said it wasn't. What needs to be measured is the current going into the battery, That's what the computer does. and that cannot be done by just measuring the current coming from the alternator, Yes, that's why there is more than one wire on the battery positive terminal. as that could also be going to lights, heaters, spark plugs, etc, etc. Yes, that's why there is more than one wire on the battery positive terminal. the alternator can't tell the difference between a battery taking 12 amps, and a battery taking 2 amps plus lights taking 10 amps. But the computer can. And knows if the lights are on too. The second one requires switching to trickle charge, the first doesn't. |
#22
Posted to alt.electronics,uk.rec.driving,alt.home.repair,uk.d-i-y
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Commander Kinsey" wrote in message news On Sat, 22 Jun 2019 00:26:13 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:39:34 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 21:54:38 +0100, Rod Speed wrote: Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. But how can the regulator on the alternator possibly know the current it's passing to the battery is going into the battery and not going straight across to the lights? The computer knows whats going to the battery and you can see that with an ODB2 dongle. My dongle only lists faults. Because it's a steaming turd with wheels frog car. Which should adhere to the ****ing OBD standards according to the frog's own EU regs!! Steaming turd with wheels frog cars don't. And that isnt an EU reg anyway. And a very basic OBD reader I bought to determine why a warning light was on. That will still show more than just faults. Most show all sorts of things. If you look at the battery in your car, there are two or three thick wires coming off each terminal. One will go to the alternator, another to the fusebox for all the lights etc. And it's the voltage across the one going from the alternator to the battery that allows the computer to know how much current is going to the battery. Bull****. We'll see... How could it possibly know if the current flows into the battery or goes to the other wire leading to the fusebox? By measuring the voltage drop across those cables, stupid. Unless there's some clever circuitry monitoring each battery wire individually and subtracting the currents, Yes there is, its called the computer. So what happened with older cars before they did that? The voltage across the battery changes as the battery is charged. Wrong. Nope. Say the alternator can produce 14V at up to 50 amps. When the battery has been used to start the car and perhaps run some lights when the engine was off, it takes maybe 25A, and the voltage is 14V, Yep. regulated by the alternator's circuitry. Nope, by the battery. When the battery becomes full, it takes only a fraction of an amp, Yep, because the battery voltage is now higher. but the voltage is still 14V. The battery voltage isnt. What needs to be measured is the current going into the battery, Nope, the current drops automatically. and that cannot be done by just measuring the current coming from the alternator, as that could also be going to lights, heaters, spark plugs, etc, etc. That's why there is more than one wire to the battery positive terminal. the alternator can't tell the difference between a battery taking 12 amps, and a battery taking 2 amps plus lights taking 10 amps. But the computer can. And knows if the lights are on too. The second one requires switching to trickle charge, the first doesn't. |
#23
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 21/06/2019 22:57, Max Demian wrote:
On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge?Â* I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Definitely. One of the simplest ways to msake a vcarger is to have a constant voltage source in series with somem form of resistor. As the terminal voltage rises so too does the charge current drop. The problem that brings is when a heavy cirrent is siltanoeusly drawn from the battery. Which is why car alternator control is a little more spohisticated than that. -- €œSome people like to travel by train because it combines the slowness of a car with the cramped public exposure of €¨an airplane.€ Dennis Miller |
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 09:26:13 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: We'll see... We'll see YOU trolling on these groups like there was no tomorrow, you 85-year-old senile pest! -- Keema Nam addressing nym-shifting senile Rodent: "You are now exposed as a liar, as well as an ignorant troll." "MID: .com" |
#25
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Lonely Psychopathic Senile Ozzie Troll Alert!
FLUSH another 142 !!! lines of absolutel troll**** unread again
-- addressing nym-shifting senile Rodent: "You on the other hand are a heavyweight bull****ter who demonstrates your particular prowess at it every day." MID: |
#26
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Lonely Psychopathic Senile Ozzie Troll Alert!
FLUSH another 137 !!! lines of the two asshole trolls' latest troll**** unread -- Richard addressing Rot Speed: "**** you're thick/pathetic excuse for a troll." MID: |
#27
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 09:57:57 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: FLUSH the two prize idiots' endless troll**** Not when there is more than one wire going to the positive terminal of the battery, and there always is. In auto-contradicting mode again, you clinically insane auto-contradicting senile asshole? G -- about senile Rot Speed: "This is like having a conversation with someone with brain damage." MID: |
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 22/6/19 9:33 am, Commander Kinsey wrote:
On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge?* I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Yip.* I can put any voltage I like across a battery's terminals.* The battery then chooses how much current is drawn. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly.* It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. For example, I'm currently keeping my car's battery topped up with a bench supply overnight.* It's set to 13.8V, with a current limiter only to prevent overloading the supply.* The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A.* The only way I or the supply can tell the battery is full, is by the current dropping to 100mA.* But it's actually always full, as when 4A is drawn, that's going to a load. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. I guess that may be true, if the car's computer has two ammeters and subtracts one from the other.** But AFAIK, the alternator regulator only works by it's own current sensor.* And that current could be going into the battery, or past it to the loads. Nope, the alternator regulator is sensing only *voltage*. -- Xeno Nothing astonishes Noddy so much as common sense and plain dealing. (with apologies to Ralph Waldo Emerson) |
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 22/6/19 9:57 am, Rod Speed wrote:
"Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge?* I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Yip. Nope. I can put any voltage I like across a battery's terminals. Nope. The battery then chooses how much current is drawn. And that current changes depending on the how charged the battery is. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly.* It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. For example, I'm currently keeping my car's battery topped up with a bench supply overnight.* It's set to 13.8V, with a current limiter only to prevent overloading the supply. It actually specify the current being supplied. The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A.* The only way I or the supply can tell the battery is full, is by the current dropping to 100mA.* But it's actually always full, as when 4A is drawn, that's going to a load. What load ?* There no load with a battery being charged with a bench supply. Correction - the *battery* is the *load*. In the process of being charged it is using electric current. That makes it the load. Even when it is fully charged it will still take a trickle charge so it is still a load even when fully charged. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. I guess that may be true, if the car's computer has two ammeters It has more than one wire to the positive terminal of the battery. So it can see what current is going to the rest of the car. and subtracts one from the other.** But AFAIK, the alternator regulator only works by it's own current sensor.* And that current could be going into the battery, or past it to the loads. Not when there is more than one wire going to the positive terminal of the battery, and there always is. -- Xeno Nothing astonishes Noddy so much as common sense and plain dealing. (with apologies to Ralph Waldo Emerson) |
#30
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Xeno" wrote in message ... On 22/6/19 9:57 am, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Yip. Nope. I can put any voltage I like across a battery's terminals. Nope. The battery then chooses how much current is drawn. And that current changes depending on the how charged the battery is. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly. It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. For example, I'm currently keeping my car's battery topped up with a bench supply overnight. It's set to 13.8V, with a current limiter only to prevent overloading the supply. It actually specify the current being supplied. The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A. The only way I or the supply can tell the battery is full, is by the current dropping to 100mA. But it's actually always full, as when 4A is drawn, that's going to a load. What load ? There no load with a battery being charged with a bench supply. Correction Nope. the *battery* is the *load*. Not when the battery is fully charges and is being charged with a bench supply that is delivering 4A to the battery. In the process of being charged it is using electric current. That makes it the load. See above. Even when it is fully charged it will still take a trickle charge 4A isnt a trickle charge. so it is still a load even when fully charged. Not when its still taking 4A, If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. I guess that may be true, if the car's computer has two ammeters It has more than one wire to the positive terminal of the battery. So it can see what current is going to the rest of the car. and subtracts one from the other. But AFAIK, the alternator regulator only works by it's own current sensor. And that current could be going into the battery, or past it to the loads. Not when there is more than one wire going to the positive terminal of the battery, and there always is. |
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Lead acid battery charger (or alternator) switching to trickle with load present?
Yes indeed, the nominal output of an alternator can be as high as 15 volts,
but even a fully charged car battery is only 13.8v as far as I know and these days, I'm sure the direction of current flow and voltages are monitored very well by the computers. In the old days it was a bit of a black art just relying on the ability of the alternator or dynamo in the old bangers. Normally the output will change due to engine speed, but in alternators there is a voltage regulator inbuilt to keep the thing pretty nominal and of course the thing that then suffers is the charging rate, ie its going to be be slower when its not running very fast. I think if a battery dips below about 11v outside of starter transients, you have to charge it or get a new one. This very accurate sensing these days can often mask a battery on its last legs though, as people tend to ignore warnings if the car still works, then they leave it a couple of days and it won't start! Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "Rod Speed" wrote in message ... Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. |
#32
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 19:58:32 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: Correction Nope. LOL Clinically insane 85-year-old senile pest! -- Kerr-Mudd,John addressing senile Rot: "Auto-contradictor Rod is back! (in the KF)" MID: |
#33
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Lead acid battery charger (or alternator) switching to trickle with load present?
Brian Gaff wrote
Yes indeed, the nominal output of an alternator can be as high as 15 volts, but even a fully charged car battery is only 13.8v as far as I know They are a bit higher than that just after being charged. and these days, I'm sure the direction of current flow and voltages are monitored very well by the computers. In the old days it was a bit of a black art just relying on the ability of the alternator or dynamo in the old bangers. Normally the output will change due to engine speed, but in alternators there is a voltage regulator inbuilt to keep the thing pretty nominal and of course the thing that then suffers is the charging rate, ie its going to be be slower when its not running very fast. I think if a battery dips below about 11v outside of starter transients, you have to charge it or get a new one. This very accurate sensing these days can often mask a battery on its last legs though, as people tend to ignore warnings if the car still works, then they leave it a couple of days and it won't start! Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "Rod Speed" wrote in message ... Commander Kinsey wrote How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? From the current the battery takes. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? You just look at the current going to the battery. The variably loads like with lights isnt supplied by the battery when the engine is running, its supplied by the alternator. |
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Troll-feeding Senile Australian ASSHOLE Alert!
On Sat, 22 Jun 2019 19:15:56 +1000, Xeno, another brain damaged,
troll-feeding, senile Australian idiot, blathered: Nope, the alternator regulator is sensing only *voltage*. Nope, it's the Scottish ****** sensing that he can have all you senile troll-feeding idiots on, time and again! BG |
#35
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Lonely Psychopathic Senile Ozzie Troll Alert!
On Sat, 22 Jun 2019 20:11:33 +1000, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again: They are a bit higher than that just after being charged. You ALWAYS have to go one better, eh, you abnormal senile asshole? Can't you see that that's the very reason why you got NO ONE in real life to talk to? BG -- Richard addressing Rot Speed: "**** you're thick/pathetic excuse for a troll." MID: |
#36
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 22/6/19 7:58 pm, Rod Speed wrote:
"Xeno" wrote in message ... On 22/6/19 9:57 am, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge?* I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Yip. Nope. I can put any voltage I like across a battery's terminals. Nope. The battery then chooses how much current is drawn. And that current changes depending on the how charged the battery is. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly.* It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. For example, I'm currently keeping my car's battery topped up with a bench supply overnight.* It's set to 13.8V, with a current limiter only to prevent overloading the supply. It actually specify the current being supplied. The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A.* The only way I or the supply can tell the battery is full, is by the current dropping to 100mA.* But it's actually always full, as when 4A is drawn, that's going to a load. What load ?* There no load with a battery being charged with a bench supply. Correction Nope. the *battery* is the *load*. Not when the battery is fully charges and is being charged with a bench supply that is delivering 4A to the battery. Take the case of an alternator charging a battery at ~4 amps. The battery is the load and it also provides, as part of that function, the reference *voltage* that the alternator *must have* in order to control the output. In the process of being charged it is using electric current. That makes it the load. See above. What happens to the charger when you disconnect the power with the battery connected? It should, if designed correctly, shut down since it no longer sees a load. Otherwise it may destroy itself. Even when it is fully charged it will still take a trickle charge 4A isnt a trickle charge. That depends entirely on the amp hour rating of the battery. Also, my bench charger will start off at 4 amps, its maximum capacity. As the battery becomes charged, that current will drop down to *1 amp* and, from that point, it will maintain a *trickle charge*. From Wikipedia; For lead-acid batteries under no load float charging (such as in SLI batteries), trickle charging happens naturally at the end-of-charge, when the lead-acid battery internal resistance to the charging current increases enough to reduce additional charging current to a trickle, hence the name. In such cases, the trickle charging equals the energy expended by the lead-acid battery splitting the water in the electrolyte into hydrogen and oxygen gases The car alternator regulator is no different. It sees the battery as a load, determines the voltage reference and pumps up its output. When the regulator sees the battery voltage at the peak setpoint, it too will drop the current to a trickle. If you add a load, say by turning headlights on, that is in *parallel* to the battery and it will drop the system voltage down a tad. The regulator will see that and pump up the output current appropriately. The current will apportion itself to the *two* loads as appropriate to their individual internal resistances. Here, educate yourself; https://www.swtc.edu/ag_power/electr...l_circuits.htm so it is still a load even when fully charged. Not when its still taking 4A, If the battery is *taking* 4 amps, then it *is definitely the load*. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. I guess that may be true, if the car's computer has two ammeters It has more than one wire to the positive terminal of the battery. So it can see what current is going to the rest of the car. and subtracts one from the other.** But AFAIK, the alternator regulator only works by it's own current sensor.* And that current could be going into the battery, or past it to the loads. Not when there is more than one wire going to the positive terminal of the battery, and there always is. -- Xeno Nothing astonishes Noddy so much as common sense and plain dealing. (with apologies to Ralph Waldo Emerson) |
#37
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Lead acid battery charger (or alternator) switching to trickle with load present?
Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? Asks the unemployable ******/troll with a 20 year old worthless degree and a stated IQ of 138. Odd that a few years ago your stated IQ was 142. |
#38
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 22/6/19 8:00 pm, Brian Gaff wrote:
Yes indeed, the nominal output of an alternator can be as high as 15 volts, but even a fully charged car battery is only 13.8v as far as I know and A 12 Volt lead acid battery will show 13.2 volts straight off the charger, about 2.2 volts per cell. That will drop to about 12.7 volts after a day or so, a tad over 2.1 volts per cell. On the other hand, a vehicle's nominal *system voltage* is 14 Volts. That's because the *alternator typically operates in the 13.8-14.2 range. Due to increasing loads on vehicle electrical equipment, manufacturers were pushing to a nominal 42 Volt electrical system on cars. They were to be equipped with a 36 Volt battery. It may not happen now. https://en.wikipedia.org/wiki/42-volt_electrical_system these days, I'm sure the direction of current flow and voltages are monitored very well by the computers. In the old days it was a bit of a black art just relying on the ability of the alternator or dynamo in the old bangers. Normally the output will change due to engine speed, but in alternators there is a voltage regulator inbuilt to keep the thing pretty nominal and of course the thing that then suffers is the charging rate, ie its going to be be slower when its not running very fast. I think if a battery dips below about 11v outside of starter transients, you have to charge it or get a new one. This very accurate sensing these days can often mask a battery on its last legs though, as people tend to ignore warnings if the car still works, then they leave it a couple of days and it won't start! Brian Most batteries fail gracefully as they progressively lose *capacity*. The first sign of impending doom is a lack of gusto on the first turn of the engine on the first cold start of the day. Batteries don't like cold weather, their chemistry just isn't happy. The rest of the day they will start pretty much as normal. Most people however aren't as attuned to this so fail to observe that subtle change. It won't get better however and it will eventually be noticeable by all and sundry as it will, one slightly colder morning, fail to start the car at all. -- Xeno Nothing astonishes Noddy so much as common sense and plain dealing. (with apologies to Ralph Waldo Emerson) |
#39
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Lead acid battery charger (or alternator) switching to trickle with load present?
"Xeno" wrote in message ... On 22/6/19 7:58 pm, Rod Speed wrote: "Xeno" wrote in message ... On 22/6/19 9:57 am, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 23:57:52 +0100, Rod Speed wrote: "Commander Kinsey" wrote in message news On Fri, 21 Jun 2019 22:57:44 +0100, Max Demian wrote: On 21/06/2019 21:19, Commander Kinsey wrote: How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? The voltage perhaps. Why would the voltage change? That's the way batterys work, the battery voltage does change as its charged. That's determined by the alternator or charger. Nope. Yip. Nope. I can put any voltage I like across a battery's terminals. Nope. The battery then chooses how much current is drawn. And that current changes depending on the how charged the battery is. Let's say the charger/alternator gives out 14.4V initially, to charge the battery quickly. It'll just sit at 14.4V forever, providing the charger can give out enough current to charge the slightly flat battery and power any connected loads. Its more complicated than that with the current going to the battery and the battery is charged. If the battery had no loads connected, it would take a lot less current when it became full, but the voltage would stay the same. No it doesn't even with a very crude battery charger. For example, I'm currently keeping my car's battery topped up with a bench supply overnight. It's set to 13.8V, with a current limiter only to prevent overloading the supply. It actually specify the current being supplied. The voltage stays at 13.8V all the time, sometimes 100mA is drawn, sometimes up to 4A. The only way I or the supply can tell the battery is full, is by the current dropping to 100mA. But it's actually always full, as when 4A is drawn, that's going to a load. What load ? There no load with a battery being charged with a bench supply. Correction Nope. the *battery* is the *load*. Not when the battery is fully charged and is being charged with a bench supply that is delivering 4A to the battery. Take the case of an alternator charging a battery at ~4 amps. That isnt what was being discussed there. What was being discussed there was charging the battery out of the car with a bench supply. The battery is the load and it also provides, as part of that function, the reference *voltage* that the alternator *must have* in order to control the output. None of that is relevant to what was being discussed there, charging the battery out of the car with a bench supply. In the process of being charged it is using electric current. That makes it the load. See above. What happens to the charger when you disconnect the power with the battery connected? With a BENCH SUPPLY, it continues to provide the same voltage as it did with the battery connected. It should, if designed correctly, shut down since it no longer sees a load. Otherwise it may destroy itself. That is just plain wrong with a BENCH SUPPLY. None of those destroy themselves with no load. Even when it is fully charged it will still take a trickle charge 4A isnt a trickle charge. That depends entirely on the amp hour rating of the battery. We're discussing a normal car battery in a steaming turd with wheels frog car. Also, my bench charger We arent discussing a bench charger, we are discussing a bench SUPPLY. will start off at 4 amps, its maximum capacity. As the battery becomes charged, that current will drop down to *1 amp* and, from that point, it will maintain a *trickle charge*. So that is nothing like the situation being discussed with a BENCH SUPPLY which is still delivering 4A to a battery that has been removed from the car. From Wikipedia; For lead-acid batteries under no load float charging (such as in SLI batteries), trickle charging happens naturally at the end-of-charge, when the lead-acid battery internal resistance to the charging current increases enough to reduce additional charging current to a trickle, hence the name. In such cases, the trickle charging equals the energy expended by the lead-acid battery splitting the water in the electrolyte into hydrogen and oxygen gases Irrelevant to what is being discussed, 4A isnt a trickle charge. The car alternator regulator is no different. We arent discussing that there. It sees the battery as a load, determines the voltage reference and pumps up its output. When the regulator sees the battery voltage at the peak setpoint, it too will drop the current to a trickle. If you add a load, say by turning headlights on, that is in *parallel* to the battery and it will drop the system voltage down a tad. The regulator will see that and pump up the output current appropriately. The current will apportion itself to the *two* loads as appropriate to their individual internal resistances. All irrelevant to charging a battery out of the car with a BENCH SUPPLY. Here, educate yourself; https://www.swtc.edu/ag_power/electr...l_circuits.htm I knew all that before you were even born, thanks. so it is still a load even when fully charged. Not when its still taking 4A, If the battery is *taking* 4 amps, then it *is definitely the load*. But it wont be taking 4A WHEN THE BATTERY IS OUT OF THE CAR WITH A BENCH SUPPLY. Because the battery voltage will have risen once it has been charged so the original 4A will have dropped significantly WITH A BENCH SUPPLY. If the charger monitored the current it was providing, how does it know if the battery is still charging at 10 amps, or if the battery is full and there's a 10 amp load? By checking the current actually being delivered to the battery. I guess that may be true, if the car's computer has two ammeters It has more than one wire to the positive terminal of the battery. So it can see what current is going to the rest of the car. and subtracts one from the other. But AFAIK, the alternator regulator only works by it's own current sensor. And that current could be going into the battery, or past it to the loads. Not when there is more than one wire going to the positive terminal of the battery, and there always is. |
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Lead acid battery charger (or alternator) switching to tricklewith load present?
On 21/06/2019 21:19, Commander Kinsey wrote:
How does a lead acid battery charger (or car alternator) know when to switch to trickle charge? It doesn't. I can understand it noticing a drop in charging current if the battery is on its own, but what if a random changing load is connected, as there is in a running car? Ohm's law. |
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