Concrete slab

Chris11

I finally got around to pouring a small slab to set 4 of my 8 deep cycle batteries upon.  I was thinking about something I was told thousands of years ago ... don't put your car batteries on concrete.  i remember asking at the time why and no one seemed to know, it's just what they were told.

Question .... was that a myth or is there some science behind that? 

Thanks, Chris

Marc Kurth

It was valid 80+ years ago due to the case materials commonly used to contain the acid at the time. Your batteries will not drain down because they sit on concrete. It is a place for moisture to collect depending upon the concrete and the ambient air conditions.

Dave Angelini

Myth but you should have some kind of containment in case a battery leaks. This is mainly to meet the building code if this was part of an inspected home. It can be as little as a tarp, a locked top to keep kids out, and a warning sign. If it is not then do what you want. 

Marc Kurth

Good point, Dave. Being an AGM guy, I tend to miss things required for flooded batteries. Containment is critical to include with flooded batteries!

Chris11

Thanks.  I was wondering about moisture gathering under the bat.  Dunno what to do about that ... or simply not worry about it.

JRHill

About all bad I can say is a slab can suck heat from the batteries in the winter. About all else I can say is a slab can help cool your batteries in the summer. But if you have temp compensation and a sensor in your bank then whatever under them - even a piece of 1" poly foam and the tarp. And prop the lid open a few inches in the summer. I used a Rubbermaid deck box and it fits 8ea L16's perfectly. No idea where you are but if it doesn't get too hot or too cold, yeah, just a tarp UNDER them.

Chris11

I left the wooden frame around the slab, and allowed room to put some insulation, then plywood walls and hinged top.  I'll use 2 x 6's under the bats for that insulation.  Holes in the sides covered with small mesh for breathing.

The temp sensor is on the other string of 4 bats inside an enclosure right beside this new one ....similarly constructed.

I won't be propping the top up .... bugs and critters would become squatters.

Spokane WA area.  Can be very hot in the summer and very cold in the winter.

Thanks for the advice.

littleharbor2

Flooded lead acid batteries and wood don't mix well. The acid tends to eat wood and generally make it a nasty mess. The 2 x 6's under the batts are mostly at risk. I haven't used flooded batteries in at least 15 years but I have the pleasure (ugh) of maintaining friends batteries in the summer and see the black nasty mess that the acid makes of wood structures. Do yourself a favor and do as Dave and Marc say

Chris11

I never knew that about bats and wood.... so thanks. 

I've had my flooded bats sitting on wood in the container I built for bats and electronics about 7 years ago.  I just had them all out since I had to rewire for the new location of 4 of the 8 bats.  The bottom wood was dirty but perfect.  From what you say about bats and wood not compatible my saving grace was probably is that I painted the whole thing before I put the bats in.  So maybe the paint saved the wood. 

I'm still going to use 2 x 6's but now I'll paint them first, which I hadn't planned on doing so thanks for the heads up.