Batteries on concrete

[DANNY8]

I've always thought sitting batteries on concrete stuffs them up?? I took a battery to an auto electrician to be charged and tested, and when I dropped it off he sat it on the concrete floor in his shed. I asked him about it saying how I thought concrete stuffs them, he said he'll sit it on a block of wood to charge it.

My bro did a delivery there the other day and said he saw it charging on a block of wood...and when I picked it up 2day I saw it sitting on the shed floor again.

What's the go?

[88GreenVN]

Dunno! I charge mine on the bench.

[azkwazere]

i see no reason why concrete would have any effect on a battery... it doesnt make sense.

aZk.

[DANNY8]

Just googled it and found some info....seems it's ok these days...
Storing Batteries on Concrete

[LightningVP]

Sitting batteries on the concrete used to drain the power out of older batteries

[Gero SV6]

At work we sit them on the bench.Took out of a new car when fitting air con one afternoon. Dead flat next morring

[garth]

i see no reason why concrete would have any effect on a battery... it doesnt make sense.

aZk.

back in the old days champ the battery walls and base use to be thin
batterys go flat quicker in a cold place, and cause the batterys were on the concrete floor, which was cold they would go flat, thats the reason.
now days they are different technology, they dont suffer from this anymore.

[Morton]

I'm no scientiest, but here's my two cents:

Concrete sucks a lot of heat. And when it's cold, it's REALLY cold. Anyone who's worked in a factory with concrete floors, and stood on rubber mats while they worked, can agree with that. When you stand on the concrete, you can feel the chills running up your legs.

Now if I'm not mistaken, leaving a battery on a cool concrete floor will cause the bottom of the battery to cool to a lower temperature than the top of the battery, which is exposed to only the warmer ambient air. Once you find a temperature gradient within the battery, you have the more excited electrolyte trying to charge another part of the battery cell, and it will gradually discharge itself.

This is why leaving the battery on a block of wood is helpful - wood isn't as heat-conductive as concrete, so there is less temperature gradient within the wood.

(this works in the same way that air is less heat-conductive than water. 100-degree water will scold your hand in a second, but you can comfortably put your hand inside a 200-degree oven for a short while.)

But as Garth said, plastics have improved, and now the base of batteries are slightly less conductive of heat. But still, it's a good idea to keep your battery off the floor, and somewhere it will remain evenly heated or cooled.

[naf33n]

im an auto electrician and this came up in tafe a few years ago. there is no proper reason for it, the teacher could not even explain it, or even confirm if its true or not,


i think its just one of those old theories that just been passed on with the years,

[commsirac]

Battery manufacturers must know the answer to this!......they have enough batteries to do the testing with...given there are no warnings written on the battery about to where to store it....Id say myth....sure there will be reps from the places that tell you otherwise, basically so they will sound knowledgeable.....and storing them on wood isnt going to hurt.

Once upon a time, as has been pointed out ^, battery cases where permeable and electroylte could seep out and form a nasty circuit with the concrete.....even todays batteries when they are vigorously charged can put layers of acid on the top of the battery....which eventually find its way to the bottom and rust out the battery holder......seen a few of them.

It would appear that people are keen to keep the art of knowing about "concrete" going by telling us about temperature gradients and the like causing self discharge. Perhaps it does, but Im not seeing any evidence for it anywhere. Convenction currents inside the battery? cant see it, if the bottom gets cold and the top is hot...this wont cause it....the opposite will.
Differences in concentration of the acid will cause a reaction....this will happen by having the battery sit anyway....the acid will become denser at the bottom. Larger batteries have stirrers to conteract this.....but is it significant in a car battery?

Is the temperature gradient significant enough? Id say not, many form an incorrect idea of how cold a concrete floor actually is, even in winter.
Sure if you walk on one you can feel it is cold, but that's because there is a large temp difference between your body and the concrete, perhaps 20C on average and concrete is a better conductor than carpet or wood.
Batteries are not warm blooded(obvious I know), on average, the difference between air temperature and the temperature of the top layer of the ground is not going to be anywhere near this value. Do also consider that the ground stays at a fairly constant temperature, its the air that causes it to change temp and that the ground temp will be warmer than the min air temp in winter etc) If anything, Id say the concrete would keep the temp of the battery more constant, which may be a good thing.

Anyway, for the time being, I keep my batteries of the concrete floor(it doesnt cost anything) until the matter is resolved at a higher level.

[Ozzie]

I worked for century yassa batterys in brissy a couple of years ago...
We had huge plastic tanks of "acid" which were charged via electrodes running from the roof.
The battery was then submerged into the tanks to fill them, then they were washed.
One thing we were'nt to do was place a filled battery on the concrete, they had to be placed streight onto a wooden pallet.
I would say all battery places work like this (not too sure)
They explained that it wasnt good for the lead cells inside the battery as the concrete drags them down or "drops them"

[gopher]

might be a topic for mythbusters

[garth]

might be a topic for mythbusters

nah, i answered the question pretty good i reckon, only apply's to a hand full of batterys, and mainly affected older style, where the base of the battery was thiner, and the electrolyte was of a crap grade or starting to loose it's ability to retain a charge. these flash new sealed type are all fine though.

the colder a soltion inside a battery goes, the less ability it has of maintaining it's charge. but it doesnt affect these new ones we have now days, dry cell batterys, and gell type arnt affected by this. we did this experiment at tafe a few years ago to make all that happen.

[Nevyn]

nah, i answered the question pretty good i reckon, only apply's to a hand full of batterys, and mainly affected older style, where the base of the battery was thiner, and the electrolyte was of a crap grade or starting to loose it's ability to retain a charge. these flash new sealed type are all fine though.

the colder a soltion inside a battery goes, the less ability it has of maintaining it's charge. but it doesnt affect these new ones we have now days, dry cell batterys, and gell type arnt affected by this. we did this experiment at tafe a few years ago to make all that happen.

sorry Garth, but so........it would still make a good one for the mythbusters. Your Garth...Jamie & Adam would do it so much better to show the difference

[TVR-190]

yes theyd be able to incorporate some explosions into it.

[Nevyn]

yes theyd be able to incorporate some explosions into it.

wouldn't be the mythbusters without an explosion or 2......but personally, I never leave a battery on concrete just in case....no harm in leaving it on a wooden bench or metal shelf.

[greenacc]

definitely one for mythbusters. i've heard of this before but the battery rep said myth. and if its a temp issue, a battery woudl get colder in your car in winter than it would sitting on concrete in summer. its more of a safety issue i reckon, if you keep batteries on the floor someones sure to trip over it, or kick their toe... ouch

[LightningVP]

definitely one for mythbusters. i've heard of this before but the battery rep said myth. and if its a temp issue, a battery woudl get colder in your car in winter than it would sitting on concrete in summer. its more of a safety issue i reckon, if you keep batteries on the floor someones sure to trip over it, or kick their toe... ouch

yeah gets annoying when there are a bunch of car batteries just lying around

[PRH]

Well i'm a qualified auto elec as well,from memory the acid aint whats charged its the plates,cant remember all the stuff (been 35 years since i did that)there is a chemical change in the lead in batteries when charged the acid also changes in its specific gravity,ie it has a higher reading on ya hydrometer,i cant say that we where ever told why ya always put batteries on a peice of wood or something,ya just did it coz the boss would kick ya bum if he seen one on the floor lol.
Its a bit like welding on vehicles with out unhooking the battery,i do it to keep the peace,but from memory ive never seen a vehicle with a fault after welding on it,i always earth the peice i'm actually welding to the vehicle and start the weld on that.
Phillip

[LightningVP]

i cant say that we where ever told why ya always put batteries on a peice of wood or something,ya just did it coz the boss would kick ya bum if he seen one on the floor lol.

HAHAHA....amazing what that can do....they should use that for TAC

"Drink and drive and we'll kick ya bum"