# battery on concrete=dead battery? **URL:** \ **Category:** Factual Questions\ **Created:** [January 22, 2004, 5:55am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588 "2004-01-22T05:55:16Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![seaworthy](https://avatars.discourse-cdn.com/v4/letter/s/a8b319/32.png) [@seaworthy](https://boards.straightdope.com/u/seaworthy)\ **Post date:** [January 22, 2004, 5:55am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/1 "2004-01-22T05:55:16Z")
Someone told me a long time ago to never put your car battery down on concrete because it will drain the battery. I accepted it without question until recently. Is this true? If so, why does it drain the battery? And would putting the battery on a stack of cinder blocks have the same effect? ---
**Author:** ![The\_Green\_Feather](https://avatars.discourse-cdn.com/v4/letter/t/8e7dd6/32.png) [@The\_Green\_Feather](https://boards.straightdope.com/u/The_Green_Feather)\ **Post date:** [January 22, 2004, 6:56am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/2 "2004-01-22T06:56:54Z")
> [@seaworthy](#): > > Someone told me a long time ago to never put your car battery down on concrete because it will drain the battery. I accepted it without question until recently. Is this true? If so, why does it drain the battery? And would putting the battery on a stack of cinder blocks have the same effect? Everyone I’ve heard say this have two things in common: 1. They are absolutely sure this is correct. 2. They have no idea why. I’ve never heard a convicing argument why this might be true. So I looked it up at [Car Talk](http://cartalk.cars.com/Columns/Archive/1996/April/14.html). ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [January 23, 2004, 7:02am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/3 "2004-01-23T07:02:06Z")
Sure, I’ve heard the old tale, even from a engineer who should have known better. One of the old explanations said it dated from the days when battery cases were made of hard rubber, which would crack if you dropped it on the concrete. I think it comes from two things: First, a battery that gets taken out and placed on the garage floor is probably on its last legs. Second, many a battery that gets put on charge is forgotten until it has cooked dry for a couple of days. :smack: ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [January 23, 2004, 7:22am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/4 "2004-01-23T07:22:28Z")
Some 10 years ago I got into an extended wrangle with a friend over this. He was sure that the old tale was true, but couldn’t come up with anything better than “Well, you see, if you put a battery on concrete the charge leaks out!” So we did a test - two charged batteries side by side, one on a concrete floor, the other on a piece of plywood with small “feet”. I let him chose the time period; the initial experiment covered 5 days. At then end of this, both batteries showed pretty much a full charge, though the one on concrete was 0.1 volts lower. He claimed this proved his theory, but I spiked that by putting it in a car, which started immediately. The next experiment went nearly three weeks, and there was negligible difference at the end. He wound up conceding that “maybe the effect isn’t all that big” but also asserting that a really long test might prove him right. ---
**Author:** ![ccwaterback](https://avatars.discourse-cdn.com/v4/letter/c/df705f/32.png) [@ccwaterback](https://boards.straightdope.com/u/ccwaterback)\ **Post date:** [January 23, 2004, 7:31am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/5 "2004-01-23T07:31:52Z")
[http://uuhome.de/william.darden/carfaq14.htm#concrete](http://uuhome.de/william.darden/carfaq14.htm#concrete) ---
**Author:** ![mjhoberiii](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@mjhoberiii](https://boards.straightdope.com/u/mjhoberiii)\ **Post date:** [January 23, 2004, 2:42pm UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/6 "2004-01-23T14:42:10Z")
> [@AskNott](#): > > I think it comes from two things: First, a battery that gets taken out and placed on the garage floor is probably on its last legs. If you have every owned a boat, you will see how false this statement is. I remove the batteries from my boat every year and I can tell you that if they were stored on a concrete floor, they would definitely be dead come spring. I’ve done that once. Now they are stored on a wood shelf, and they are always fully charged when I put them back in the boat. ---
**Author:** ![Skammer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/skammer/32/143_2.png) [@Skammer](https://boards.straightdope.com/u/Skammer)\ **Post date:** [January 23, 2004, 3:00pm UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/7 "2004-01-23T15:00:49Z")
> [@mjhoberiii](#): > > I can tell you that if they were stored on a concrete floor, they would definitely be dead come spring. Why would that be? The battery manufacturers mentioned in the Car Talk article linked above say that they often store batteries on the cool concrete floor purposely to _preserve_ the charge. If no one can explain how an insulated car battery can lose it’s charge on concrete but not a wood shelf, I’m going to believe it’s an old wive’s tale (or old grease monkey’s tale). ---
**Author:** ![robby](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robby/32/11048_2.png) [@robby](https://boards.straightdope.com/u/robby)\ **Post date:** [January 23, 2004, 3:13pm UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/8 "2004-01-23T15:13:44Z")
Placing a battery on a concrete floor will **not** cause it to self-discharge any faster than placing it on any other surface! In fact, it will probably _decrease_ the tendency for the battery to self-discharge. (See below.\*) The only effect that I can see that causes people like **mjhoberiii** to insist that it does is that concrete floors (and the ground in general), are generally considerably colder in the early spring than the outside air temperature. By heat conduction, this may cause the battery stored on the ground to be colder than the air temperature. Battery voltage, like that of all galvanic cells, is temperature-dependent. (Look up the _Nernst Equation_ in a chemistry book for more information.) A cold battery will have less discharge voltage than a warm battery. All you have to do, though, to increase the discharge voltage to normal is to allow your battery to warm up. \*In fact, it would be _preferable_ to store batteries on a concrete floor, as the coolness will slow down the tendency for the battery to self-discharge. Just warm up the battery before trying to use it. BTW, I know a fair amount about batteries. I was the Electrical Officer on a U.S. submarine, responsible for (among other things) the 126-cell main storage battery with an approximate capacity of 6000 A-hr. I also taught chemistry for five years. **mjhoberiii** , the purpose of this message board is to fight ignorance, not perpetuate it. Do you have anything to support your contention beyond your own anecdotal experience? ---
**Author:** ![seaworthy](https://avatars.discourse-cdn.com/v4/letter/s/a8b319/32.png) [@seaworthy](https://boards.straightdope.com/u/seaworthy)\ **Post date:** [January 23, 2004, 3:55pm UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/9 "2004-01-23T15:55:58Z")
Wow, thanks guys. Now I can go tell off my friend for being such a jackass. He so wholeheartedly believes this story that he thinks it applies to all batteries, not just the ones in cars. I remember the day we were hanging out at the beach and he kept yelling at me for setting his radio on the seawall. Even if it were true, I thought the plastic would serve as a barrier. But it doesn’t matter anyway. What a dork. ---
**Author:** ![MidiMagic](https://avatars.discourse-cdn.com/v4/letter/m/cc9497/32.png) [@MidiMagic](https://boards.straightdope.com/u/MidiMagic)\ **Post date:** [October 14, 2015, 12:53am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/10 "2015-10-14T00:53:55Z")
I have the final answer on this. It was an auto tip in a 1930s Popular Science: “Leaving a car battery on a concrete floor will ruin it.” It really happens. I have seen three concrete floors ruined by leaving car batteries on them Acid fumes or leaking acid eats away the concrete. That word “it” has too many antecedents. ---
**Author:** ![MidiMagic](https://avatars.discourse-cdn.com/v4/letter/m/cc9497/32.png) [@MidiMagic](https://boards.straightdope.com/u/MidiMagic)\ **Post date:** [October 14, 2015, 1:07am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/11 "2015-10-14T01:07:04Z")
I have the real answer. This started in an auto tip in Popular Science in the 1930s: “Leaving a car battery on a concrete floor will ruin it.” This does actually happen. I have seen three concrete floors ruined by leaving car batteries on them. Leaking acid vapors eat the concrete. Nothing happens to the battery. That word “it” has too many antecedents. ---
**Author:** ![Razncain](https://avatars.discourse-cdn.com/v4/letter/r/9d8465/32.png) [@Razncain](https://boards.straightdope.com/u/Razncain)\ **Post date:** [October 14, 2015, 1:34am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/12 "2015-10-14T01:34:59Z")
“It” sure does. 🙂 Interesting if that is how it all got started. I haven’t bothered to track it down. I remember nobody being too sure in my dad’s paint and body shop, so we always put the batteries on wood first instead of the concrete itself, just to be on the safe side, but of course just thinking it would ruin the battery. If that’s how it all got started, they got a hell of lot of mileage out of it. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [October 14, 2015, 1:41am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/13 "2015-10-14T01:41:16Z")
Hi MidiMagic, Welcome to the Straight Dope. I saw your post in the old thread about [dead car batteries on concrete floors](http://boards.straightdope.com/sdmb/showthread.php?t=236087). It’s an interesting response, it would be nice if you could link to some information showing that a 1930s issue of Popular Science contained that line. Even if not it’s still a interesting and clever addition to that thread. I’ll let one of the mods know about this thread that isn’t really a General Question, or any kind of question. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [October 14, 2015, 1:43am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/14 "2015-10-14T01:43:42Z")
> [@razncain](#): > > “It” sure does. 🙂 Interesting if that is how it all got started. I haven’t bothered to track it down. I remember nobody being too sure in my dad’s paint and body shop, so we always put the batteries on wood first instead of the concrete itself, just to be on the safe side, but of course just thinking it would ruin the battery. > > If that’s how it all got started, they got a hell of lot of mileage out of it. I was told to put it on wood because concrete would make the battery case crack. Never heard any reasoning to support that. ---
**Author:** ![steatopygia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steatopygia/32/3132_2.png) [@steatopygia](https://boards.straightdope.com/u/steatopygia)\ **Post date:** [October 14, 2015, 1:44am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/15 "2015-10-14T01:44:21Z")
To the OP; I like it. Not sure if I believe it, but I like it. ---
**Author:** ![Razncain](https://avatars.discourse-cdn.com/v4/letter/r/9d8465/32.png) [@Razncain](https://boards.straightdope.com/u/Razncain)\ **Post date:** [October 14, 2015, 2:18am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/16 "2015-10-14T02:18:53Z")
**MidiMagic,** I did a quick search using some of the info you provided for my search engines, but only could come up with other threads by you such as this one on the [Physics forum](https://www.physicsforums.com/threads/the-final-answer-to-the-car-battery-on-a-concrete-floor-ruins-the-floor.837522/) you also started today. There you mentioned you actually have the 1930’s Popular Science with the original tip in it, but said not to ask you which issue. If we had a specific year and/or month, we could track it fairly quick through on-line archives. ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [October 14, 2015, 6:33am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/17 "2015-10-14T06:33:20Z")
> [@MidiMagic](#): > > I have the final answer on this. > > It was an auto tip in a 1930s Popular Science: > > “Leaving a car battery on a concrete floor will ruin it.” > > It really happens. > > I have seen three concrete floors ruined by leaving car batteries on them > > Acid fumes or leaking acid eats away the concrete. > > That word “it” has too many antecedents. I think this (the graped text) might indicate that _batteries that leak acid tend to stop working_, rather than anything at all to do with concrete. ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [October 14, 2015, 8:43am UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/18 "2015-10-14T08:43:24Z")
> [@Mangetout](#): > > I think this (the graped text) might indicate that _batteries that leak acid tend to stop working_, rather than anything at all to do with concrete. It also means that sulphuric acid is not good for concrete floors. ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [October 14, 2015, 12:28pm UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/19 "2015-10-14T12:28:50Z")
Pronoun trouble? ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [October 14, 2015, 2:14pm UTC](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588/20 "2015-10-14T14:14:56Z")
**MidiMagic** ’s information is accurate, but very much outdated. There are two things going on here. The first is that battery cases in the old days were made out of hard rubber. That rubber also happened to be slightly porous. If you left a battery on a concrete floor, some of the electrolyte would ooze out of the battery and onto the concrete. This leaked electrolyte would form a conductive path and slowly drain the battery, in addition to doing whatever damage it would do to the concrete floor. In 1930, this warning was certainly applicable. In modern times, though, they have been making battery cases out of non-porous plastic for a very long time now, which makes the warning more than a little outdated. Modern batteries are also usually sealed, which means they don’t emit fumes either. The second thing is that if you have a battery in a warm room with a cold floor, you can set up a temperature differential across the battery. This can cause the electrolyte to stratify, which results in tiny currents flowing through the electrolyte due to the density differences. These tiny currents cause the battery plates to sulfate, ruining the battery. Large battery systems will sometimes have stirring systems built into them to prevent this from happening. For a battery as small as a car battery though, I’ve read conflicting information about whether you can even get enough of a density variation to get any significant current flow, so it may be that car batteries are just too small to worry about. In order for the electrolyte to stratify, it has to be left sitting still for a fairly long time. This won’t happen overnight. We’re talking about leaving a battery untouched for weeks on end. If you are worried about it, pick up the battery and give it a good shake about once a week. [Next page](https://boards.straightdope.com/t/battery-on-concrete-dead-battery/225588.md?page=2)