Galke Kimbrough, Interstate's Battery Answer Man, states the following:
" Well, is it true? Will a battery be damaged or discharged by letting it sit on concrete? NO!
Why then do so many people believe that concrete is a battery enemy? Years ago, batteries could have been electrically discharged by sitting on a concrete floor. My dad, for instance, owned an automotive shop for many years. In fact, I grew up on a creeper. My dad reminded me time after time, "Set that battery on wood! I know batteries discharge on concrete because I’ve witnessed it!" And he was right at that time.


Historical Basis


You see, the myth that concrete drains batteries does have some historical basis. Many, many years ago, wooden battery cases encased a glass jar with the battery inside. Any moisture on the floor could cause the wood to swell and possibly fracture the glass, causing it to leak. Later came the introduction of the hard rubber cases, which were somewhat porous and had a high-carbon content. An electrical current could be conducted through this container if the moist concrete floor permitted the current to find an electrical ground. The wise advice of the old days to "keep batteries off concrete" has been passed down to us today, but it no longer applies because of the advanced technology of today’s batteries.


Today’s Technology


For more than a decade, automotive and commercial battery containers have been made of polypropylene, which is a highly insulative material. In fact, the Interstate Batteries poly material is at least five times more insulative than the old hard rubber. Also, tremendous technological improvements have been made in the seals around the posts and the vent systems, which have virtually eliminated electrolyte seepage and migration.


Battery Discharging


The fact is, all batteries self- discharge whether they’re sitting on the shelf or on concrete. This is why we regularly rotate your inventory. As the temperature increases, a battery’s self-discharge level also increases. Some lead acid batteries discharge 4% - 8% per month at a temperature of 80°F. The level of self-discharge is also contingent upon the type of lead plate alloy plus the age and cleanliness of the battery.

If the battery has a surface layer of acid or grime, which is electrically conductive, it self-discharges more rapidly. This surface layer may actually allow you to measure the DC voltage across the battery’s poly case (using a 10 meg-ohm digital voltmeter). For that reason, we recommend that you always keep batteries clean, whether they’re in storage or in a vehicle.


Grandfather Clause


You may now be thinking that you know more than your grandfather, who tells you that batteries stored on concrete will be damaged. Next time your grandfather says that, I recommend that you just say "Okay" and continue about your business. I’m a grand-father now, and I know that we like to have our way and we like to be right. If my grandson, for instance, tries to tell me that concrete won’t damage a battery, you know what I’ll say? I’ll say if you drop a battery on concrete, it will be damaged.

However, in a reply to this, an Interstate battery dealer tried to prove Kimbrough right by simultaneously charginbg one battery on a block of wood and another on concrete. The Battery on wood charged, the other one didn't. Of course, this is charging, not storage. I think I will store any batteries I need to store on a piece of wood. Thgat device sounds like a pretty clever thing.




"Tech Talk" is a copyright of Interstate Battery System of America.

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Semibodacious Transmogrifications a Specialty

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Richard,
I applaud you. You have taken the initiative to learn even if it meant discovering you had misconceptions. I have learned from apprentices and have given them verbal credit. Any person who thinks he or she has all the answers is a fool. You were curious about the performance of a battery in cold weather. Ironicaly a battery in service is adversally affected by cold weather. As temperature decreases,battery performance decreases. They are directly proportional. The common car battery is taken for granted when in fact a whole 3 semester hour course would be required to explain them. CAR54 where are you?

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Auto Zentral Ltd.

The very best way is to poor the acid out of it. There's industrial (military) applications for batteries to sit for very long times and have power when needed. There is typically an automatic system that has two seperate chambers, one for acid, one for lead. On demand a valve opens and bingo, a fully charged battery.

I also remember motorcycle batteries being sold seperatly, battery and acid. There's all sorts of changing laws about handling and transporting lead-acid batteries and that was a technique to comply with some.

FYI

Car Batteries

SOME MYTHS ABOUT BATTERIES

A. Storing a battery on a concrete floor will discharge them.

Modern lead acid battery cases are better sealed, so external leakage causing discharge is no longer a problem. [Temperature stratification within large batteries can accelerate the internal "leakage" or self discharge if the battery is sitting on an extremely cold floor in a warm room.]

B. Driving a car will fully recharge a battery.

There are a number of factors affecting alternator's ability to charge a battery.The greatest factors are how much current from the alternator is diverted to the battery to charge it, how long the current is available and temperature.Generally, running the engine at idle or short "stop-and go trips" during bad weather at night will not recharge the battery.

C. A battery will not explode.

While spark retarding vent caps help, recharging a battery produces hydrogen and oxygen gasses.Battery explosions can also occur when the electrolyte level is below the top of the plates. If a spark or flame occurs, an explosion will occur.

D. A battery will not lose it's charge sitting in storage.

A battery has self discharge or internal electrochemical "leakage" that will cause it to become fully discharged and sulfated over time.Prior to storing a battery, it should be fully charged, placed in a cool location above freezing, and recharged when it reaches the 80% state-of-charge level or once every six months, whichever occurs first.If left in a vehicle, disconnect the negative cable.

E. Maintenance free batteries never require electrolyte.

In hot climates, the electrolyte could be "boiled off" due to the high underhood temperatures.Electrolyte could also be lost due to excessive harging voltage or charging currents.

F. Test the alternator by disconnecting the battery with the engine running.

A battery is like a voltage stabilizer or filter to the pulsating DC
produced by the alternator. Disconnecting a battery while the engine is running can destroy the electronic components, e.g., computers, radio, stereo, alarm system, etc., or the charging system. Just say NO! if anyone suggests this.

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Reno

'93 300E 4Matic
'98 Nissan Altima
'00 Yamaha Road Star Silverado

The trick here for prolonged storage seems to be to keep the battery always fully charged, but not to put so much juice into it that the electrolyte will boil off. Probably 1/4 - 1 amp max. would be about right.

Why not simply fully charge your battery with a real battery charger, then hook it up to one of those small 12 vdc transformers that were made to power small units such as cell phone chargers, toys, etc. Most folks have drawers full of them around the house. Simply hook one of those up to your battery and it should nicely do the trick of keeping your battery at peak for no equipment cost and damn little electricity cost.

Anyone have any negative comments about this concept?

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'76 240D-Sold
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'86 560SL 124K Miles-Sold
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07 SL550, 14K Miles

Just a thought on storing batteries for yourself... would freezing the battery be bad? If you can freeze the cells, you'd stop the chemical reaction, or at least slow it down very greatly, so it will in theory discharge very slowly or not at all. Then thaw it and use or charge it. Bad idea? I'm not going to attempt this, I just thought of it because of chemical reactions being slowed in colder climates.

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1984 190D 2.2 Auto 220k
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Freezing the battery will usually crack or damage the plates inside the case, if not the case itself. I'm not sure what happens to the electrolyte--it it is ruined or not.

Reno,
You summed it up very well. I can only add a few details. When you remove the load on an alternator by removing a battery lead, you not only risk destruction of electronic components,you may also destroy the alternator. The voltage can surge close to 100 volts. Also alternators are designed to keep a battery charged and not to recharge a dead battery. If you continue to use an alternator to recharge a dead battery, it will fail prematurely. When you experience a battery exploding and call a battery expert, he or she will ask you if you have a Ford Escort.

Peter

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Auto Zentral Ltd.

190D22,
You might have an interesting theory.

Dweller,

You must remember the importance of specific gravity. A discharged battery will have a specific gravity near that of water witch will freeze at 32* F. Once I went skiing in Idaho when the temp went to 36* below. Of course at this temp the battery couldn't power a flashlight.I took the battery to the condo and put it in a sink full of hot water twice. With the battery at a temp of about 80*,I fired up my 1980 Celica. In my opinion Toyota makes the best of the rice burners. In this temperature you always leave a stick in neutral. You always run the engine a short time and shut it off several times til the oil flows. By the way I depend on Interstate Bateries. Now I'll shut and wait for the cold country experts to tell me better. This is just my way.

Thanks,
Peter

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Auto Zentral Ltd.

NEVER FREEZE A CAR BATTERY! - Here in cold Canada - a fully charged car battery can survive -40F no problem AS LONG AS THE BATTERY IS CHARGED. The higher specific gravity of the electrolyte in a charged battery prevents it from freezing. Discharge the battery, or drain it severely and within 4 hours it will be frozen - and worthless. In extreme cold weather here - if a car cranks and cranks and does not start - we have to immediately recharge the battery to prevent it from being destroyed. Apparently when the electrolyte solution has a low specific gravity from being low on charge - ice crystals start to form and if left long enough at below freezing temps. the electrolyte will freeze hard and as it does so - will crack the material off the plates leaving the plastic grid with little or nothing on it - resulting in a battery that is dead or will not hold a usable charge. As I said in a different thread - my daughter had a bad alternator and drove home with her lights on in the dark 17 miles - by the time she got home the lights were very dim (it is a diesel) and the battery was frozen and had to be replaced. - Just my experience with batteries and freezing - Oh by the way - it is a known trick up here that if you freeze flashlight batteries - they will last longer until the time comes to use them. - But they are a different breed of battery than lead-acid.

Yeah I kinda figured there was a reason why no one mentioned freezing of a battery. I do keep my AA and 9V batteries in the fridge along with camera film, so you slow down the chemical reaction there and when you use them they are 'fresher.' I figured I'd ask. Later.

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1984 190D 2.2 Auto 220k
2001 Jeep Cherokee Sport 70K
2004 Lexus RX-330 ??K
2005 Chrylser Crossfire LTD 6K

Play guitar? Go to www.cyberfret.com for free online lessons!