Thread: Batteries on a concrete floor

Have also heard of this one, never really known whether it was true or not, but any battery I stored on a concrete floor was usually destined for battery heaven.

A quick google found this

In the early 1900s, when battery cases were made of porous materials such as tar-lined wood boxes, storing batteries on concrete floor would accelerate their natural self-discharge due to external leakage. Modern battery cases are made of polypropylene or hard rubber. These cases are sealed better, so external leakage-causing discharge is no longer a problem, provided the top of the battery is clean and free from wet or dried electrolyte and the same temperature as the floor.
Large differences in temperature could cause electrolyte stratification within very large batteries (>250 AH) which could accelerate it's internal "leakage" or self-discharge if the battery is sitting on an extremely cold concrete, stone or steel floor in a warm room, boat or submarine. Stirrers or bubblers are often used on these types of large batteries to keep the electrolyte from stratifying. Undercharging will also cause electrolyte stratification, which can also result in loss of capacity from sulfation.

Martyn

The logic I've got on it is more for charging than storage and theres a side logic for storage on a wooden surface.

the logic against charging is to do with the convection currents setup within the battery while charging. The batteries warm up when they get charged, if you have it sitting on a cold slab then the hot stuff gets to the top and stays there, hot acid is better at taking a charge than the cold stuff so the batteries plates dont get "used" equally when you then let the battery sit the acid sorts itself out within the cell over time (or when you chuck it in the car and start driving it around) because the reaction is more evenly distributed during use the plates get deposits forming at the same rate. The deposits forming limit the usefullness of the plate and therefore the battery. Done often enough the deposits will form bridges and short out within the cell and thats the end of the battery.

The secondary logic for not storing your batteries directly on the concrete comes about when something goes wrong with the battery and it leaks, Its easier to chuck out a piece of timber thats been acid marked than it is to clean up the mess that forms on the concrete. This is especially relevant if the cement has reo in it and is not sealed. If the acid makes it to the metal it promotes oxidisation and that cracks the cement.

Originally Posted by Blknight.aus

The logic I've got on it is more for charging than storage and theres a side logic for storage on a wooden surface.

the logic against charging is to do with the convection currents setup within the battery while charging. The batteries warm up when they get charged, if you have it sitting on a cold slab then the hot stuff gets to the top and stays there.

Hi Dave and I don’t often disagree with you but this one has a problem.

If the concrete kept the base of the battery cool and posed problems then any metal tray would cause an even greater potential problem because it would act like a big heat sink and transfer much greater amounts of battery heat, and would, if the theory was correct, make every vehicle’s battery tray a battery killer.

Anyway, that’s how I see it.

yep, but then the battery is normally in the engine bay which is heated by the engine. Generally theres also a rubber mat in the bottom of most battery trays and in modern cars they have those insulation bags...

It does of course raise the real question of...

why if the convection current thing is true did the establishment that taught me that theory have a metal bench to charge the batteries on in the battery charging room?

Just checked my retired 6year old AGM the other day. I took it out about 4 months ago. Read 12.84 volts. Not too much wrong with that and sitting on concrete all that time.

Regards Philip A

I fully agree with Drivesafe on this one. I have spoken to many a battery expert and they all say the same. It does not apply to modern batteries due to water/acid proof plastic cases.

Dave.

I cant answer the question....but I do know that during my time at 2 CAV in Darwin, over the wet season, batteries (**** loads of them) were removed from vehicles, and locked up on pallets connected to trickle chargers.

I always though it might have something to do with the use of lifting equipment.....but the only lifting equipment ever used was "biological".

I've run into this one two, especially on a few jobs running safari camps, where people used to say we needed to keep the batteries from the solar system and inverter up on wooden blocks. I couldn't see how it would make any difference. All I can say is that all those batteries ended up resting on the concrete and were fine afterwards for a long time.....