Why you (maybe) shouldn't store car batteries on the ground

Magazine articles and old timers often advise that car batteries should not be stored on the ground but none of them ever offer an explanation for why that matters..
Well here's why the ground is different and how to avoid problems.

[@dandearman2871]

The battery voltage is effected by the temperature of the electrolyte in the cells. Because of the difference in temperature between the ground and the air around the battery there can be a temperature difference in the electrolyte from the bottom of the cells to the top of the cells and this temperature difference will also cause a voltage difference from the bottom to the top of the cells that will cause the cells to discharge. I read an article years ago about submarines having problems from this with the cold ocean on one side of the batteries and the warmer inside of the submarine. Their solution was to put tubes down into the batteries to make a trail of bubbles to keep the electrolyte stirred up. I've never proved this one way or the other so take it for what it's worth. For sure, a clean battery and a battery maintainer is your best shot.

[@SN95Power]

Great information. I never knew

[@TheSkubna]

The olden day batteries had a heavy duty rubber compound for the case. The acid slowly soaks the pores in the case, and can complete the connection with earth

[@kevinroberts781]

Todays car battery can be safely left on the ground but you must keep a mantainer hooked to it. LA batteries have bad self discharge and they will sulfate the plates if they discharge. Plus if its cold outside a dead car battery will freeze.
The reason they said never to leave a car battery on the ground was because 80 years ago car batteries didn't have the plastic cases we have today. Back then they used other materials that were porous. It was very easy for those old batteries to make a mild short and self discharge. Todays batteries won't do that by just sitting on the ground.