Battery Experts! Inside please.

[Max Power]

Again Hack, I live in the Twin Cities. I know the weather here.

The reason batteries suffer in the cold is that loads increase exponentially with decrease in temperature. The battery is cranking just fine, but the engine requires something like 400% more current at 20 below than it does at 20 above.

Also, heat that kills a battery doesn't just come from ambient outdoor tempurature. It comes from the design of your engine bay, and the spacing of the plates in the battery. That why you don't see 1000cca batteries in 24f cases anymore. They all got warrantied in less than two years cuz the batteries were so crammed full of plates that they couldn't cool.

The cement floor thing is a myth.

 

[Max Power]

Oh, and Nitrous Eater, did you look at the Battery Tender link I posted? They have an automatic cycler and timer built in.

 

[WORTH]

Again Hack, I live in the Twin Cities. I know the weather here.

The reason batteries suffer in the cold is that loads increase exponentially with decrease in temperature. The battery is cranking just fine, but the engine requires something like 400% more current at 20 below than it does at 20 above.

Also, heat that kills a battery doesn't just come from ambient outdoor tempurature. It comes from the design of your engine bay, and the spacing of the plates in the battery. That why you don't see 1000cca batteries in 24f cases anymore. They all got warrantied in less than two years cuz the batteries were so crammed full of plates that they couldn't cool.

The cement floor thing is a myth.

I can vouch for the underhood temp problem, the boys at the local FD had econoline based ambulances with twin batteries under the hood, they would fry them in about 6 months. So we build battery boxes under the side and solved the problem, they get 2-3 years out of them now. When I got the majicbus (90 E350 w/460) the first thing we did was relocate the batteries. They have been going strong now for about 3 years.

 

[Max Power]

BTW Hack, if you can get ten years out of a battery, don't change a thing!!!

 

[Ozsum2]

Again Hack, I live in the Twin Cities. I know the weather here.

The reason batteries suffer in the cold is that loads increase exponentially with decrease in temperature. The battery is cranking just fine, but the engine requires something like 400% more current at 20 below than it does at 20 above.

Also, heat that kills a battery doesn't just come from ambient outdoor tempurature. It comes from the design of your engine bay, and the spacing of the plates in the battery. That why you don't see 1000cca batteries in 24f cases anymore. They all got warrantied in less than two years cuz the batteries were so crammed full of plates that they couldn't cool.

The cement floor thing is a myth.

I always heard and thought that a cold engine was hard to start because the oil was thicker, nothing to do with the engine itself. And when it is cold outside, the battery looses something like 30 to 60% of its CCA, so how can a battery be cranking just fine if it is below optimun CCA?

 

[Hack]

I always heard and thought that a cold engine was hard to start because the oil was thicker, nothing to do with the engine itself. And when it is cold outside, the battery looses something like 30 to 60% of its CCA, so how can a battery be cranking just fine if it is below optimun CCA?

I think you're right on the money with both points. I think the chemical reaction within the battery is slowed in cold temps, so it can't recover or put out the same CCA.

I think a battery goes dead quicker when cold - just leave your lights on for 8 hours in the summer, then try it again in the dead of winter. There will be a difference.

I'll see if I can find a tech link somewhere to back this up and post it tonight.

 

[Max Power]

hack your point contradicts itself. If a battery cant flow as much when cold, why would it discharge quicker when cold? That doesn't make sense. The reason the battery has a harder time starting the car after 8 hours in the cold is because it is trying to start a cold car, not because it discharged quicker.

Yes, batteries have less cranking power when cold, but still have plenty to turn the engine over. The rule used to be 1cc per cubic inch displacement. Most batteries have 600-650cca, so there is more than enough cranking power.

Oz, you are correct, the fliuds become a huge drag as temps dip, not the engine. Not only is the oil a lot thicker, but with automatic cars, you have to turn all that fluid in the converter. Also, electrical circuits offer more resistence when cold, if I am not mistaken, so the starter and cables would offer more drag.

 

[Ozsum2]

hack your point contradicts itself. If a battery cant flow as much when cold, why would it discharge quicker when cold? That doesn't make sense. The reason the battery has a harder time starting the car after 8 hours in the cold is because it is trying to start a cold car, not because it discharged quicker.

Yes, batteries have less cranking power when cold, but still have plenty to turn the engine over. The rule used to be 1cc per cubic inch displacement. Most batteries have 600-650cca, so there is more than enough cranking power.

Oz, you are correct, the fliuds become a huge drag as temps dip, not the engine. Not only is the oil a lot thicker, but with automatic cars, you have to turn all that fluid in the converter. Also, electrical circuits offer more resistence when cold, if I am not mistaken, so the starter and cables would offer more drag.

I think Hack was right when he said the battery was "flatter" when cold. The charge isn't the same when cold. The battery looses some of it's "juice" when cold as compared to when warm.

 

[Max Power]

I can't argue with that point. There is some reduced cranking ability. The main problem is the increased load though.

 

[Hack]

I read some articles and none were what I really wanted. I do see where elevated temps reduce a battery's life. I'm not sure what physically happens, though. I guess it might be harder to keep gasses in solution at a higher temp. Perhaps my battery has lasted so long because my six cylinder doesn't generate much heat. Or maybe it's because my only electrical accessories are headlights, turn signals and the original AM radio.

Max your points are well taken. However, I'm quite certain that a battery will discharge faster in the cold. I could be wrong though. I think that colder temps change the chemical reaction's equilibrium point as well as its reaction rate. I don't think the charge in a battery is the same as the water in a glass. If you heat the battery and boil off the acid, the battery is dead, for instance. If you freeze the battery, same thing.

 

[Max Power]

A battery will not discharge faster in the cold, but it's cranking amps will reduce. Current flow slower in cold weather, which is why starters and electrical systems create an increased drag.

I looked on my battery last night as I was trying to fire up my new 393, and it said at 32F it had 625cca, and at 0f it had 550 CCA. That is a reduction in cranking amps of about 20%, so I imagine at 20 below, the cca would be reduced by another 20% or so.

Even battery mfgs for little batteries like Duracells recommend storing your batteries in a cool dry place, like your refrigerator.

This is what they tought me in trade school, what they tought me for my certification tests, and what ten years sellings batteries for Johnson Controls taught me.

While that is not empirical evidence, for me, it's the way to bet!

BTW, try turning a motor over by hand when it is cold vs warm. You will get the idea.

 

[Hack]

A battery will not discharge faster in the cold, but it's cranking amps will reduce. Current flow slower in cold weather, which is why starters and electrical systems create an increased drag.

I looked on my battery last night as I was trying to fire up my new 393, and it said at 32F it had 625cca, and at 0f it had 550 CCA. That is a reduction in cranking amps of about 20%, so I imagine at 20 below, the cca would be reduced by another 20% or so.

Even battery mfgs for little batteries like Duracells recommend storing your batteries in a cool dry place, like your refrigerator.

This is what they tought me in trade school, what they tought me for my certification tests, and what ten years sellings batteries for Johnson Controls taught me.

While that is not empirical evidence, for me, it's the way to bet!

BTW, try turning a motor over by hand when it is cold vs warm. You will get the idea.

Yep I'm still with you 100% on cold storage.

I still believe that the total power available from a battery changes with temperature. I'm open to being proven wrong, but until then..

 

[Platonic Solid]

A battery will not discharge faster in the cold, but it's cranking amps will reduce. Current flow slower in cold weather, which is why starters and electrical systems create an increased drag.

I looked on my battery last night as I was trying to fire up my new 393, and it said at 32F it had 625cca, and at 0f it had 550 CCA. That is a reduction in cranking amps of about 20%, so I imagine at 20 below, the cca would be reduced by another 20% or so.

Even battery mfgs for little batteries like Duracells recommend storing your batteries in a cool dry place, like your refrigerator.

This is what they tought me in trade school, what they tought me for my certification tests, and what ten years sellings batteries for Johnson Controls taught me.

While that is not empirical evidence, for me, it's the way to bet!

BTW, try turning a motor over by hand when it is cold vs warm. You will get the idea.

If resistance increases as temperature increases, how can "current flow slower in cold weather"?

For what it’s worth, Consumer Reports did a storage test on small batteries, keeping half the test samples in room temp. and the rest in the fridge. End result, no noticeable difference in battery life between the two lots.