Home |
Search |
Today's Posts |
![]() |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
|
#1
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
About 5 years ago, I bought a solar charger for charging cell phones. It
seemed like a great idea, and worked fine for a year at most. Then it would charge for a minute or so, and shut itself off. It could also be charged by hooking it to a USB port on a computer or use a phone charger. It had 4 blue LEDs that were supposed to indicate the amount of charge it contained. Even after charging form a USB, it did not charge a phone anymore. It's been sitting in a box ever since. I just connected it to a USB charger and it would not even take a charge anymore. I took it apart and was expecting to find some AA or AAA NiCd batteries, similar to the ones that are inside of those sidewalk solar lights. My plan was to replace those batteries with NiCd cells, the same way I change them in those solar lights that quit working. When I opened it, I was shocked. Instead of AA or AAA batteries, I found two square "pouches". Sort of like tin foil covered bags that are labeled as batteries. They are flexible, squishy, and just have two contacts labeled + and - (there are two of them). I have never seen batteries like this. Besides those weird batteries, I found a small circuit board with 6 or 7 very small IC chips. One with 16 pins, and the rest have 6 pins each. Plus an electrolytic cap, and a small coil which is probably some sort of choke, and several surface mounted things which I assume are resistors. Also the USB plugs and those 4 LEDs are connected to that board. All of this seems very complex for such a small charger, and those chips are so small I can barely see the leads on them, much less try to repair this thing. Heck, I need a magnifying glass just to see the solder joints on this thing. The plan is to salvage the solar panel, and trash the rest of it. The solar panel is a lot bigger than the ones on those solar lights, (about 4 x 5 inches). I'm suspecting the solar panel is still good, (I will have to test it to be sure, by hooking a volt meter to it when it's in the sun). My question is whether I can connect this solar panel directly to a rechargable battery, or do I need some sort of diode or other components between it, and the battery(s). (I know those solar lights have very minimal components). But it seems to me that there probably needs to be some sort of component (at least a diode) to protect the battery current from back-flowing into the solar panel. In the end, this will just become a solar charger for NiCd or NiMh rechargable batteries, or I might even turn it into a solar light sort of thing. Anyhow, what is needed to attach this solar panel to a common rechargable AA or AAA battery? Thanks! |
#2
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]() |
#3
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Saturday, 15 July 2017 21:19:12 UTC+1, wrote:
About 5 years ago, I bought a solar charger for charging cell phones. It seemed like a great idea, and worked fine for a year at most. Then it would charge for a minute or so, and shut itself off. It could also be charged by hooking it to a USB port on a computer or use a phone charger. It had 4 blue LEDs that were supposed to indicate the amount of charge it contained. Even after charging form a USB, it did not charge a phone anymore. It's been sitting in a box ever since. I just connected it to a USB charger and it would not even take a charge anymore. I took it apart and was expecting to find some AA or AAA NiCd batteries, similar to the ones that are inside of those sidewalk solar lights. My plan was to replace those batteries with NiCd cells, the same way I change them in those solar lights that quit working. When I opened it, I was shocked. Instead of AA or AAA batteries, I found two square "pouches". Sort of like tin foil covered bags that are labeled as batteries. They are flexible, squishy, and just have two contacts labeled + and - (there are two of them). I have never seen batteries like this. Besides those weird batteries, I found a small circuit board with 6 or 7 very small IC chips. One with 16 pins, and the rest have 6 pins each. Plus an electrolytic cap, and a small coil which is probably some sort of choke, and several surface mounted things which I assume are resistors. Also the USB plugs and those 4 LEDs are connected to that board. All of this seems very complex for such a small charger, and those chips are so small I can barely see the leads on them, much less try to repair this thing. Heck, I need a magnifying glass just to see the solder joints on this thing. The plan is to salvage the solar panel, and trash the rest of it. The solar panel is a lot bigger than the ones on those solar lights, (about 4 x 5 inches). I'm suspecting the solar panel is still good, (I will have to test it to be sure, by hooking a volt meter to it when it's in the sun). My question is whether I can connect this solar panel directly to a rechargable battery, or do I need some sort of diode or other components between it, and the battery(s). (I know those solar lights have very minimal components). But it seems to me that there probably needs to be some sort of component (at least a diode) to protect the battery current from back-flowing into the solar panel. In the end, this will just become a solar charger for NiCd or NiMh rechargable batteries, or I might even turn it into a solar light sort of thing. Anyhow, what is needed to attach this solar panel to a common rechargable AA or AAA battery? Thanks! Likely the fault is with the squishy lithium batteries. If you want to use just the panel, some allow dark current leakage, some don't. Hook it to a battery, put it in darkness and measure. If it leaks add a diode. Charge control depends on battery chemistry & size. NiCd & NiMH can be charged by just limiting current delivery to C/16, so measure your panel output current in full sun as well as offload voltage. Lithium is much more fussy, hence some of the circuitry. NT |
#5
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Sunday, 16 July 2017 02:24:07 UTC+1, Jeff Liebermann wrote:
On Sat, 15 Jul 2017 17:58:46 -0700 (PDT), tabbypurr wrote: Likely the fault is with the squishy lithium batteries. The first step to solving a problem is to blame someone or something. However, in this case, you're probably right. If the OP had the skill to fault find I'd think they''d already have tried to If you want to use just the panel, some allow dark current leakage, some don't. Hook it to a battery, put it in darkness and measure. If it leaks add a diode. Unless the solar cells (or panel) have built in diodes, most everything I've seen exhibits dark current (leakage). Charge control depends on battery chemistry & size. NiCd & NiMH can be charged by just limiting current delivery to C/16, so measure your panel output current in full sun as well as offload voltage. Lithium is much more fussy, hence some of the circuitry. I beg to differ. You might be able to trickle charge NiCd, but NiMH is considerably more picky: http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride "It is difficult, if not impossible, to slow charge a NiMH battery. At a C rate of 0.1C to 0.3C, the voltage and temperature profiles do not exhibit defined characteristics to trigger full-charge detection, and the charger must depend on a timer. Harmful overcharge can occur when charging partially or fully charged batteries, even if the battery remains cold." In other words, C/16 or 0.06C charge rate for NiMH screws up the NVD (negative voltage detection) mechanism used to detect EoC (end-o-charge), which can easily overcharge a NiMH cell or battery. My cordless phones use NiMH with no charge control. They get charged or discharged all the time. Last set of cheap cells lasted at least 1500 cycles. So you can do it. NT |
#6
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Sun, 16 Jul 2017 02:28:25 -0700 (PDT), wrote:
On Sunday, 16 July 2017 02:24:07 UTC+1, Jeff Liebermann wrote: On Sat, 15 Jul 2017 17:58:46 -0700 (PDT), tabbypurr wrote: Charge control depends on battery chemistry & size. NiCd & NiMH can be charged by just limiting current delivery to C/16, so measure your panel output current in full sun as well as offload voltage. Lithium is much more fussy, hence some of the circuitry. I beg to differ. You might be able to trickle charge NiCd, but NiMH is considerably more picky: http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride "It is difficult, if not impossible, to slow charge a NiMH battery. At a C rate of 0.1C to 0.3C, the voltage and temperature profiles do not exhibit defined characteristics to trigger full-charge detection, and the charger must depend on a timer. Harmful overcharge can occur when charging partially or fully charged batteries, even if the battery remains cold." In other words, C/16 or 0.06C charge rate for NiMH screws up the NVD (negative voltage detection) mechanism used to detect EoC (end-o-charge), which can easily overcharge a NiMH cell or battery. My cordless phones use NiMH with no charge control. Maker and model please. I want to see if I can find a schematic. They get charged or discharged all the time. Last set of cheap cells lasted at least 1500 cycles. So you can do it. NT I hate to admit it but you are probably correct. My AT&T EL52210 Dect 6.0 handset https://www.google.com/search?q=at%26t+el52210&tbm=isch uses two AAA 2.4v 400ma-hr NiMH cells. The battery label demands that I charge the battery for 16 hrs prior to use. Doing the math and assuming constant current charging, that's a C/16 charge rate. I disassembled the charger base and took some photos: http://www.11junk.com/jeffl/pics/repair/AT-T%20charger%20base/index.html Not much inside. 6VAC 300ma wall wart, diode bridge, filter cap, and some unidentified diodes and transistor. I'll trace out the circuit and identify the parts if I have time. Without an IC to do the NVD detection, this charger is rather crude and probably does not follow the recommendations from the Battery University site. Incidentally, the phone is 5 to 8 years old and shows no sign of battery problems. The handsets spend most of their life in the charger base and the batteries have never been discharged to the point where the handset complains. Open circuit battery voltage is now 2.68V which is very much full charge for NiMH. Very strange. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#7
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Sunday, 16 July 2017 18:36:48 UTC+1, Jeff Liebermann wrote:
On Sun, 16 Jul 2017 02:28:25 -0700 (PDT), tabbypurr wrote: On Sunday, 16 July 2017 02:24:07 UTC+1, Jeff Liebermann wrote: On Sat, 15 Jul 2017 17:58:46 -0700 (PDT), tabbypurr wrote: Charge control depends on battery chemistry & size. NiCd & NiMH can be charged by just limiting current delivery to C/16, so measure your panel output current in full sun as well as offload voltage. Lithium is much more fussy, hence some of the circuitry. I beg to differ. You might be able to trickle charge NiCd, but NiMH is considerably more picky: http://batteryuniversity.com/learn/article/charging_nickel_metal_hydride "It is difficult, if not impossible, to slow charge a NiMH battery. At a C rate of 0.1C to 0.3C, the voltage and temperature profiles do not exhibit defined characteristics to trigger full-charge detection, and the charger must depend on a timer. Harmful overcharge can occur when charging partially or fully charged batteries, even if the battery remains cold." In other words, C/16 or 0.06C charge rate for NiMH screws up the NVD (negative voltage detection) mechanism used to detect EoC (end-o-charge), which can easily overcharge a NiMH cell or battery. My cordless phones use NiMH with no charge control. Maker and model please. I want to see if I can find a schematic. They get charged or discharged all the time. Last set of cheap cells lasted at least 1500 cycles. So you can do it. NT I hate to admit it but you are probably correct. My AT&T EL52210 Dect 6.0 handset https://www.google.com/search?q=at%26t+el52210&tbm=isch uses two AAA 2.4v 400ma-hr NiMH cells. The battery label demands that I charge the battery for 16 hrs prior to use. Doing the math and assuming constant current charging, that's a C/16 charge rate. I disassembled the charger base and took some photos: http://www.11junk.com/jeffl/pics/repair/AT-T%20charger%20base/index.html Not much inside. 6VAC 300ma wall wart, diode bridge, filter cap, and some unidentified diodes and transistor. I'll trace out the circuit and identify the parts if I have time. Without an IC to do the NVD detection, this charger is rather crude and probably does not follow the recommendations from the Battery University site. Incidentally, the phone is 5 to 8 years old and shows no sign of battery problems. The handsets spend most of their life in the charger base and the batteries have never been discharged to the point where the handset complains. Open circuit battery voltage is now 2.68V which is very much full charge for NiMH. Very strange. BT graphite 1100 series. I saved you the time & googled, no trace of a circuit anywhere. So I could be wrong, but I'd be surprised if there were any charge control electronics in such equipment. Such non-ideal battery charging schemes are widespread, more or less universal really, in many types of equipment. NT |
#8
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Sat, 15 Jul 2017 15:15:03 -0400, wrote:
When I opened it, I was shocked. Instead of AA or AAA batteries, I found two square "pouches". Sort of like tin foil covered bags that are labeled as batteries. Those are LiPo (lithium polymer) batteries, normally used in cell phones and quadcopters. Photos: https://www.google.com/search?q=lithium+polymer+batteries&tbm=isch Besides those weird batteries, I found a small circuit board with 6 or 7 very small IC chips. That's the charge controller. Heck, I need a magnifying glass just to see the solder joints on this thing. You'll also need specialized tools to build and repair those, such as a hot air desoldering station, reflow oven, solder paste, and various chip manipulation tools. The plan is to salvage the solar panel, and trash the rest of it. The solar panel is a lot bigger than the ones on those solar lights, (about 4 x 5 inches). I'm suspecting the solar panel is still good, (I will have to test it to be sure, by hooking a volt meter to it when it's in the sun). You might also want to measure the short circuit current. Just put an ammeter across the solar cell leads and see what you get. My question is whether I can connect this solar panel directly to a rechargable battery, No. or do I need some sort of diode or other components between it, and the battery(s). Yes, a solar charge controller. What type and size depend on the ratings of the solar panel and LiPo battery, neither of which are currently well defined. (I know those solar lights have very minimal components). They also do a great job of killing batteries. LiPo lasts longer than most, but few batteries will last very long after being cycled between full charge and total discharge every day. But it seems to me that there probably needs to be some sort of component (at least a diode) to protect the battery current from back-flowing into the solar panel. True. Schottky diode for minimum voltage drop. It's often inside the charge controller chip. In the end, this will just become a solar charger for NiCd or NiMh rechargable batteries, or I might even turn it into a solar light sort of thing. In the end, if you use it as a solar powered garden light, you'll likely kill the battery. You need to match the battery, charge controller, and solar cell to each other. So far, you're not doing that. Anyhow, what is needed to attach this solar panel to a common rechargable AA or AAA battery? Better numbers. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#9
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Sat, 15 Jul 2017 18:12:14 -0700, Jeff Liebermann
wrote: On Sat, 15 Jul 2017 15:15:03 -0400, wrote: When I opened it, I was shocked. Instead of AA or AAA batteries, I found two square "pouches". Sort of like tin foil covered bags that are labeled as batteries. Those are LiPo (lithium polymer) batteries, normally used in cell phones and quadcopters. Photos: https://www.google.com/search?q=lithium+polymer+batteries&tbm=isch Yep, that's what they look like. I have never seen these before now... Besides those weird batteries, I found a small circuit board with 6 or 7 very small IC chips. That's the charge controller. Heck, I need a magnifying glass just to see the solder joints on this thing. You'll also need specialized tools to build and repair those, such as a hot air desoldering station, reflow oven, solder paste, and various chip manipulation tools. Yep, I'm sure they sell all this stuff, but I'm not investing the money in it. I'd probably spend several hundred dollars to get all this stuff, then spend a thousand dollars to my eye doctor for eye strain, trying to see these parts. Then I'd remove parts, which are not labeled, and after wasting hours trying to understand it, I'd still end up tossing it in the trash. I think I spent around $25 for this charger, and dont think I got my money's worth out of it, but I am fully aware it is not meant to be repaired. Like most stuff these days, it's disposible. I'm not even considering repairing it, I just want to salvage the solar cell and make use of it. I should also mention that last winter Walmart had some portable cellphone chargers that are meant to be used when the phone's battery dies. You charge these power packs by connecting them to any phone charger or USB port. These battery packs sold for $6. I bought two of them. If I plan ot use my phone in a place that has no means to recharge the phone's internal battery, I just carry these power packs in my pocket. I thought the solar charger was better, but since it did not last even a year. I spent close to $20 to save about 50 cents worth of electricity to recharge a battery pack. The plan is to salvage the solar panel, and trash the rest of it. The solar panel is a lot bigger than the ones on those solar lights, (about 4 x 5 inches). I'm suspecting the solar panel is still good, (I will have to test it to be sure, by hooking a volt meter to it when it's in the sun). You might also want to measure the short circuit current. Just put an ammeter across the solar cell leads and see what you get. My question is whether I can connect this solar panel directly to a rechargable battery, No. or do I need some sort of diode or other components between it, and the battery(s). Yes, a solar charge controller. What type and size depend on the ratings of the solar panel and LiPo battery, neither of which are currently well defined. So, does this have to be designed by hand with individual components, or is there a chip available that does it all? -OR- can a ready made board be purchased that is intended to control solar chargers? (I know those solar lights have very minimal components). They also do a great job of killing batteries. LiPo lasts longer than most, but few batteries will last very long after being cycled between full charge and total discharge every day. I have to disagree about these solar lights killing batteries. I have several of these lights mounted on my house, and several more on my workshop shed. I paid from $5 to $10 for them. I attach them with 1/2" conduit straps to the wall. Some of them have lasted 5 years, others have died after 2 years. But considering they are charged and drained 365 times each year, and operate off of one NiCd battery, I really cant complain, about their life expectancy. Every so often a local store sells replacement batteries in a 4 pack, ON SALE for about $6. So, for $1.50 per light, I just replace the dead batteries, and get another two or more years from the lights. Now, if you buy those solar lights that cost $1, they DO NOT last long. And I also found that if you stick them in the ground along a sidewalk, they get broken faster than the batteries die, and if you dont step on them or chop them up with the lawn mower, they wont survive the snow in winter. Wall mounted is so much better, and in my case they perform an inportant task, they light up the stairs by my door, without needing to operate an AC porch light, which will cost a lot more on the electric bill. But it seems to me that there probably needs to be some sort of component (at least a diode) to protect the battery current from back-flowing into the solar panel. True. Schottky diode for minimum voltage drop. It's often inside the charge controller chip. So, would one of these diodes be all that I really need to use this solar panel? In the end, this will just become a solar charger for NiCd or NiMh rechargable batteries, or I might even turn it into a solar light sort of thing. In the end, if you use it as a solar powered garden light, you'll likely kill the battery. You need to match the battery, charge controller, and solar cell to each other. So far, you're not doing that. Anyhow, what is needed to attach this solar panel to a common rechargable AA or AAA battery? Better numbers. I guess you mean I need to determine the output of the solar panel. I'll have to see what I can measure. |
#10
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]() |
#11
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Sun, 16 Jul 2017 18:46:16 -0400, Ralph Mowery
wrote: In article , says... You'll also need specialized tools to build and repair those, such as a hot air desoldering station, reflow oven, solder paste, and various chip manipulation tools. Yep, I'm sure they sell all this stuff, but I'm not investing the money in it. I'd probably spend several hundred dollars to get all this stuff, then spend a thousand dollars to my eye doctor for eye strain, trying to see these parts. Then I'd remove parts, which are not labeled, and after wasting hours trying to understand it, I'd still end up tossing it in the trash. I think I spent around $25 for this charger, and dont think I got my money's worth out of it, but I am fully aware it is not meant to be repaired. Like most stuff these days, it's disposible. A couple of years ago I decided I needed to get set up for the small stuff. As this is just a hobby I bought some inexpensive gear. The 10 x stereo microscope was the most at $ 200. The a hot air rework station with a small soldering iron was another $ 60. Then about $ 800 for solder wick, solder paste, tweezers and a few other things. The most expensive was the pound of.015 inch solder that will last me a lifetime. I agree, many things are not made to be repaired. The parts cost more than a new item. Like one older battery drill. The batteries would not hold a charge. For slightly more than one battery, I bought another drill of better quality that had 2 batteries. This is a hobby for me too, but I dont even want to work on the extremely small stuff. I'd leave the hobby real fast. I find stuff that small very nerve wracking to work on, and since my eyesight is not real good, I cant see the stuff too well. Not to mention that for most of that stuff, you cant even get parts since they dont ID the parts anymore, and even if they did, as you said the parts cost more than the item. I enjoy working on tube stuff. I will tackle some early transistor stuff if it's worth fixing, but I usually only work on stuff that I enjoy doing. I only tore this solar charger apart to save the solar cell panel. I know the unit was trash before I even opened it. None of the chips on it even have any numbers. Before I even spend an hour on that thing, I'd sooner buy another solar phone charger for around $25. (not that same brand though). But I dont really need one anyhow. Those $6 battery packs work just fine and I can charge them on my computer, with my AC phone charger, or in my car with my car phone charger. I dont even use my phone real much, but it always seems to need charging when I do need it. Those power packs work just fine. |
#12
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Monday, 17 July 2017 06:30:39 UTC+1, wrote:
On Sun, 16 Jul 2017 18:46:16 -0400, Ralph Mowery wrote: In article , says... You'll also need specialized tools to build and repair those, such as a hot air desoldering station, reflow oven, solder paste, and various chip manipulation tools. Yep, I'm sure they sell all this stuff, but I'm not investing the money in it. I'd probably spend several hundred dollars to get all this stuff, then spend a thousand dollars to my eye doctor for eye strain, trying to see these parts. Then I'd remove parts, which are not labeled, and after wasting hours trying to understand it, I'd still end up tossing it in the trash. I think I spent around $25 for this charger, and dont think I got my money's worth out of it, but I am fully aware it is not meant to be repaired. Like most stuff these days, it's disposible. A couple of years ago I decided I needed to get set up for the small stuff. As this is just a hobby I bought some inexpensive gear. The 10 x stereo microscope was the most at $ 200. The a hot air rework station with a small soldering iron was another $ 60. Then about $ 800 for solder wick, solder paste, tweezers and a few other things. The most expensive was the pound of.015 inch solder that will last me a lifetime. I agree, many things are not made to be repaired. The parts cost more than a new item. Like one older battery drill. The batteries would not hold a charge. For slightly more than one battery, I bought another drill of better quality that had 2 batteries. This is a hobby for me too, but I dont even want to work on the extremely small stuff. I'd leave the hobby real fast. I find stuff that small very nerve wracking to work on, and since my eyesight is not real good, I cant see the stuff too well. Not to mention that for most of that stuff, you cant even get parts since they dont ID the parts anymore, and even if they did, as you said the parts cost more than the item. Surface mount parts are trivial to get for nothing. NT |
#13
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]() |
#14
![]()
Posted to sci.electronics.repair
|
|||
|
|||
![]()
On Sunday, 16 July 2017 21:36:17 UTC+1, wrote:
On Sat, 15 Jul 2017 18:12:14 -0700, Jeff Liebermann wrote: On Sat, 15 Jul 2017 15:15:03 -0400, wrote: But it seems to me that there probably needs to be some sort of component (at least a diode) to protect the battery current from back-flowing into the solar panel. True. Schottky diode for minimum voltage drop. It's often inside the charge controller chip. So, would one of these diodes be all that I really need to use this solar panel? any diode, doesn't need to be schottky. But you've still got to get the numbers right. Start with measuring the panel's offload voltage & short circuit current in full sun. NT |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
how do I connect a quick connect to a kohler faucet | Home Repair | |||
AA rechargable battery life tester | Metalworking | |||
rechargable NiMH battery question | Electronics Repair | |||
Refill a 24v rechargable drill battery? | UK diy |