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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. |
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Why Won't a Frozen Battery Start a Vehicle.
A battery that is perfectly good why when it is -30C
won't it start a vehicle. Please note we are referring to a perfectly good battery and a totally functioning car. What is happening to the battery that it cannot crank the starter fast enough. Chemically something is happening inside the battery. Is it the electrolyte that freezes and chemically do what it should do? Does something happen to the lead plates? Does the 12 volts drop to a lower voltage? Does the current output of the battery drop? The cold is doing something to the battery What Is That Something? Well informed auto mechanics please step up to the plate! I do not need to start my vehicle my spare battery connected in parallel with the frozen battery does that. If your frozen battery won't start your vehicle and you remove it and take it indoors and let it heat up to house temperature, after reinstall it on the vehicle' it will then start the vehicle. What is happening to the battery internally at -30C? Denny B |
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Why Won't a Frozen Battery Start a Vehicle.
On Thu, 29 Jan 2004 19:36:57 -0700, "Denny B"
wrote: A battery that is perfectly good why when it is -30C won't it start a vehicle. Snip The cold is doing something to the battery What Is That Something? Well informed auto mechanics please step up to the plate! I do not need to start my vehicle my spare battery connected in parallel with the frozen battery does that. If your frozen battery won't start your vehicle and you remove it and take it indoors and let it heat up to house temperature, after reinstall it on the vehicle' it will then start the vehicle. What is happening to the battery internally at -30C? Denny B Most chemical action slows down as temp decreases. But a bad or discharged lead-acid battery has taken up most of acid so there much water and will freeze and ruin the battery. But a well maintained old diesel car with quality 3 year old battery will still start in -30C. That why tune ups, using thinner oil for cold temps, keeping major electical connections clean (grounds, ground straps, power wires etc), charging system working, good gas and injectors (or glow plugs) in good order helps to keep battery's. Ditto to cooling system & working thermostat. All this helps car's battery life longer in turn a reliable car. I had dramatic actually violent action with oxiclean when I dumped a teaspoonful of that powder into hot water was just poured from kettle. Grew a big foam head and ruined pig-hair brush into floppy condition like spragehetti. Do same with ice-cold water, oxiclean barely fizz. Oxiclean is great stuff to destink & degrease cat-sprayed tv parts. Did this to save a nice JVC 32" set. Cheers, Wizard |
#3
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Why Won't a Frozen Battery Start a Vehicle.
Chemical reactions slow down the colder the tempreature. Batteries are no
different. Battery capacity and maximum current capability decrease to less and less the colder it gets. If your battery is " perfectly good " meaning it has the original capacity (which it won't after a few months and decreases more over time.).. AND Your car is "totally functioning" meaning it is in tip-top condition, which it probably is not (Even though it starts in warm weather). The bugger WILL start in -30F. SO... Your car won't start because the battery ain't " perfectly good " and / or your car ain't "in tune" Sorry. -- Steve N, K,9;d, c. i My email has no u's. "Denny B" wrote in message ... A battery that is perfectly good why when it is -30C won't it start a vehicle. Please note we are referring to a perfectly good battery and a totally functioning car. What is happening to the battery that it cannot crank the starter fast enough. Chemically something is happening inside the battery. Is it the electrolyte that freezes and chemically do what it should do? Does something happen to the lead plates? Does the 12 volts drop to a lower voltage? Does the current output of the battery drop? The cold is doing something to the battery What Is That Something? Well informed auto mechanics please step up to the plate! I do not need to start my vehicle my spare battery connected in parallel with the frozen battery does that. If your frozen battery won't start your vehicle and you remove it and take it indoors and let it heat up to house temperature, after reinstall it on the vehicle' it will then start the vehicle. What is happening to the battery internally at -30C? Denny B |
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Why Won't a Frozen Battery Start a Vehicle.
I had dramatic actually violent action with oxiclean when I dumped a
teaspoonful of that powder into hot water was just poured from kettle. Grew a big foam head and ruined pig-hair brush into floppy condition like spragehetti. Do same with ice-cold water, oxiclean barely fizz. Oxiclean is great stuff to destink & degrease cat-sprayed tv parts. Did this to save a nice JVC 32" set. Cheers, Wizard Lol!! Sorry..... this made me crack up!!! Cheers!!! ) -- Skip |
#5
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Why Won't a Frozen Battery Start a Vehicle.
Hmm... if cat spray is conductive and it contacted the flyback....
-- Skip "Jason D." wrote in message ... On Thu, 29 Jan 2004 19:36:57 -0700, "Denny B" wrote: A battery that is perfectly good why when it is -30C won't it start a vehicle. Snip The cold is doing something to the battery What Is That Something? Well informed auto mechanics please step up to the plate! I do not need to start my vehicle my spare battery connected in parallel with the frozen battery does that. If your frozen battery won't start your vehicle and you remove it and take it indoors and let it heat up to house temperature, after reinstall it on the vehicle' it will then start the vehicle. What is happening to the battery internally at -30C? Denny B Most chemical action slows down as temp decreases. But a bad or discharged lead-acid battery has taken up most of acid so there much water and will freeze and ruin the battery. But a well maintained old diesel car with quality 3 year old battery will still start in -30C. That why tune ups, using thinner oil for cold temps, keeping major electical connections clean (grounds, ground straps, power wires etc), charging system working, good gas and injectors (or glow plugs) in good order helps to keep battery's. Ditto to cooling system & working thermostat. All this helps car's battery life longer in turn a reliable car. I had dramatic actually violent action with oxiclean when I dumped a teaspoonful of that powder into hot water was just poured from kettle. Grew a big foam head and ruined pig-hair brush into floppy condition like spragehetti. Do same with ice-cold water, oxiclean barely fizz. Oxiclean is great stuff to destink & degrease cat-sprayed tv parts. Did this to save a nice JVC 32" set. Cheers, Wizard |
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Why Won't a Frozen Battery Start a Vehicle.
On Thu, 29 Jan 2004 19:36:57 -0700 "Denny B"
wrote: A battery that is perfectly good why when it is -30C won't it start a vehicle. If the battery is actually FROZEN then it is not perfectly good. Perfectly good batteries have acid which won't freeze until well below -30C. As the battery becomes discharged, the freezing point moves up, so the only thing wrong with it may be that it has just not been getting fully charged. A FROZEN battery won't put out much current because the chemicals are not mobile enough to get to and from the plates freely. If the battery is just cold, then its output will be reduced simply because the battery works by means of a chemical reaction. A simple rule of thumb is that a typical chemical reaction takes place half as fast for any 10 degree C reduction in temp. The reduction in battery output does not go down this fast because there are other things also at work here, meaning that there are effects other than thermal which limit battery current. All batteries are less effective at cold temps. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- |
#7
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Why Won't a Frozen Battery Start a Vehicle.
It is imperative that when starting a car in very cold
weather that the headlights be turned on for 2 minutes BEFORE trying to start it. An engine in cold weather due to shrinkage of metal and stiffness of the lubricating oil increases the starting load a battery 'sees' by several hundred percent. As others have mentioned, a cold battery has less chemical action to produce electricity. So at cold temps, your battery is only putting out maybe 30% of its capacity, and the engine is three or more times harder to turn over! So other than bringing the battery or engine indoors to warm up, what can be done? Headlights are a lower load, and are variable as well (they will glow dimly on weak battery). And as electricity flows through something, heat is generated. This is true for a battery as well! (yes, current doesn't just flow out of a battery, it flows through it as well) So while the headlights are dimly lit, they are slowly warming up the battery. You will notice during cold times like that, the headlights will start to glow a dull orange, and after a couple of minutes, they will be shining brightly. That is when you attempt to start the engine. If you don't let the headlights do their work, the battery will never have a enough juice to start the car, the starter will discharge the battery and it will not warm up. Ren Tescher formerly of North Dakota Denny B wrote: A battery that is perfectly good why when it is -30C won't it start a vehicle. Please note we are referring to a perfectly good battery and a totally functioning car. What is happening to the battery that it cannot crank the starter fast enough. Chemically something is happening inside the battery. Is it the electrolyte that freezes and chemically do what it should do? Does something happen to the lead plates? Does the 12 volts drop to a lower voltage? Does the current output of the battery drop? The cold is doing something to the battery What Is That Something? Well informed auto mechanics please step up to the plate! I do not need to start my vehicle my spare battery connected in parallel with the frozen battery does that. If your frozen battery won't start your vehicle and you remove it and take it indoors and let it heat up to house temperature, after reinstall it on the vehicle' it will then start the vehicle. What is happening to the battery internally at -30C? Denny B |
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Why Won't a Frozen Battery Start a Vehicle.
With all due respect to someone who's probably been there and done that,
this technique is a balance of battery capacity against the heating effect. The connections and conductors inside the battery are designed to be very low resistance and therefore have a very low IR drop and low resulting I squared R loss - aka heat. The chemical reaction which produces the current is not exothermic - it does not generate heat. So the hear so generated is quite minimal. It is possible that getting the current flowing can improve some poor connections by causing heating. This may help, but is still draining the battery. You are, however, draining the battery as well. I believe that if the battery is in reasonably good condition and the car kept up, this technique won't help (won't be needed)... However if the reverse is true then all bets are off. I always preferred to keep things in good condition rather than rely on a dubious "head lamp preheat". In all cases that I have had starting problems at -20 or -30 F. fixing the battery or tuning up the engine always helped/prevented it. If it works, go ahead and do it. -- Steve N, K,9;d, c. i My email has no u's. "Ren Tescher" wrote in message ... [snip] Headlights are a lower load, and are variable as well (they will glow dimly on weak battery). And as electricity flows through something, heat is generated. This is true for a battery as well! (yes, current doesn't just flow out of a battery, it flows through it as well) So while the headlights are dimly lit, they are slowly warming up the battery. You will notice during cold times like that, the headlights will start to glow a dull orange, and after a couple of minutes, they will be shining brightly. That is when you attempt to start the engine. If you don't let the headlights do their work, the battery will never have a enough juice to start the car, the starter will discharge the battery and it will not warm up. Ren Tescher formerly of North Dakota |
#9
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Why Won't a Frozen Battery Start a Vehicle.
Ren Tescher, thank you kindly for this information.
I am going to hard wire a trickle charger ( 11/2--2Amps) across the battery and when the weather is - 25C or lower and I plug in the block heater, I will also plug in the trickle charger which will pass current through the battery and hopefully start the vehicle. Thanks kindly Denny B "Ren Tescher" wrote in message ... It is imperative that when starting a car in very cold weather that the headlights be turned on for 2 minutes BEFORE trying to start it. An engine in cold weather due to shrinkage of metal and stiffness of the lubricating oil increases the starting load a battery 'sees' by several hundred percent. As others have mentioned, a cold battery has less chemical action to produce electricity. So at cold temps, your battery is only putting out maybe 30% of its capacity, and the engine is three or more times harder to turn over! So other than bringing the battery or engine indoors to warm up, what can be done? Headlights are a lower load, and are variable as well (they will glow dimly on weak battery). And as electricity flows through something, heat is generated. This is true for a battery as well! (yes, current doesn't just flow out of a battery, it flows through it as well) So while the headlights are dimly lit, they are slowly warming up the battery. You will notice during cold times like that, the headlights will start to glow a dull orange, and after a couple of minutes, they will be shining brightly. That is when you attempt to start the engine. If you don't let the headlights do their work, the battery will never have a enough juice to start the car, the starter will discharge the battery and it will not warm up. Ren Tescher formerly of North Dakota Denny B wrote: A battery that is perfectly good why when it is -30C won't it start a vehicle. Please note we are referring to a perfectly good battery and a totally functioning car. What is happening to the battery that it cannot crank the starter fast enough. Chemically something is happening inside the battery. Is it the electrolyte that freezes and chemically do what it should do? Does something happen to the lead plates? Does the 12 volts drop to a lower voltage? Does the current output of the battery drop? The cold is doing something to the battery What Is That Something? Well informed auto mechanics please step up to the plate! I do not need to start my vehicle my spare battery connected in parallel with the frozen battery does that. If your frozen battery won't start your vehicle and you remove it and take it indoors and let it heat up to house temperature, after reinstall it on the vehicle' it will then start the vehicle. What is happening to the battery internally at -30C? Denny B |
#10
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Why Won't a Frozen Battery Start a Vehicle.
On Mon, 16 Feb 2004 13:23:22 -0600 "Steve Nosko"
wrote: With all due respect to someone who's probably been there and done that, this technique is a balance of battery capacity against the heating effect. The connections and conductors inside the battery are designed to be very low resistance and therefore have a very low IR drop and low resulting I squared R loss - aka heat. The chemical reaction which produces the current is not exothermic - it does not generate heat. So the hear so generated is quite minimal. I agree completely. I think the "headlights on" recommendation is pure rural legend and most likely counterproductive. I won't claim to have faced ND winters, but Wis winters can certainly be bad enough, and I've started my car in more than my share of -20F, or lower, temps. - ----------------------------------------------- Jim Adney Madison, WI 53711 USA ----------------------------------------------- |
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