[OT] automotive battery

Mom's car, sitting for 2.5 years had to be moved. The Interstate 72 mo. battery that was put in just before storage won't take a charge...no surprise, I put another new one in. Rather than turning in the core for $12 I will get it replaced under warranty. Is there any way to keep a new battery on the shelf for extended periods of time? Should I keep it on a trickle charger? Is it an urban myth that sitting on concrete will kill it?

Reply to
Tom Gardner
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I have about 7 batteries in the garage, 4 marine deep cycle and 3 auto batts. About once a month or when I am not too lazy or forgetful whichever comes first I put them on a trickle charger overnight. I have had the auto battiers for about a year now and the marine batts over two years. All still goin strong.

Not sure about the myth but I think that I have heard from a friend of a friends cousins mother in law that that will not discharge, but I still keep my batts on a wooden shelf..

Searcher1

Reply to
Searcher1

I use (and love) a device called a "Battery Tender" when I let my motorcycle sit over the winter. It's about the size of a big wall wart and has lots of ways you can configure the end that attaches to your vehicle. My bike has a power plug that's always connected to the battery (intended for heated clothing) so I just plug it in there. The unit is completely intelligent and flat out works. Every guy I know that has a big motorcycle has one. It's exactly what you need. - GWE

Reply to
Grant Erwin

Reply to
JR North

Was the car sitting outside in freezing weather? If it was and the battery self discharged (about 3% a month) and then froze, it may well have be ruined by the expansion of the freezing electrolyte. But if it wasn't frozen, read on.

When you say "won't take a charge" do you mean that it will accept a reasonable charging current for several hours but then not deliver any significant current to a load? If that's it, the battery has croaked.

Or, do you mean when you hook it up to a charger it doesn't draw any current?

I've seen the latter happen with "run down" batteries, but if I turn the charging voltage way up and leave them connected to the charger, after

15 minutes or so they suddenly start drawing reasonable charging current and will then charge normally. It's some sort of battery chemistry thing I never learned the reason for.

Yes, trickle charging an unused battery with a "smart" charger is a good idea.

The concrete thing is an urban myth. Back when battery cases were made of asphalt or hard rubber they used to store them on wooden pallets at garages and battery shops rather than on the concrete floor. The reason for that was so that if the battery jockeys set them down "hard" the case didn't crack like it might if it was clunked down onto concrete.

Modern battery cases can stand much more knocking around.

'Course if you cracked the case by setting it down hard on concrete, the acid would leak out of one or more cells and you WOULD find the battery dead when you went to use it.

Jeff

Reply to
Jeff Wisnia

A lead/acid battery begins to deteriorate as soon as it is activated (acid is installed), whether it is put into use or just sits on the shelf. If it sits on the retailer's shelf for a year before you purchase it, it is a one-year-old battery that you've purchased.

Hint: When shopping for a battery, try to purchase a "dry charged" battery. This is one that has not been activated and can sit on the retail shelf indefinitely without any maintenance. When you purchase it, the retailer installs the acid to activate it. Deterioration starts as soon as the acid is installed.

Batteries come from the factory "dry charged". The acid comes in a separate container that is included with the battery. Retailers (or their distributors) tend to install the acid as soon as the battery plus acid shipment is received from the factory due to Hazardous Materials handling regulations that require the acid to be installed by someone specially trained in handling such materials. The HazMat specialist is usually a contractor that comes in after hours to install the acid. This is convenient for the retailer but, for you the purchaser, it means that you are not getting a "factory fresh" battery. To ensure that you are getting a "factory fresh" battery, you must observe the acid being installed with your own eyeballs after you purchase the battery.

Yes, preferably an automatic one to prevent overcharging.

A lead/acid battery loses 5 to 10 percent (depending on ambient temperature) of its charge per month sitting anywhere. Concrete has nothing to do with it.

Reply to
Speechless

Most battery warranties are prorated, so be prepared to pay about a third of the battery's cost, at least.

The concrete thing had to do with the bakelite shell. When the concrete's would get too cold, the battery would freeze, crack or break open the case, and the acid all over the floor made for a real mess. I think there was some chemical interaction, too, but I forgot what it was. Battery cases are made of plastic now, so there's nothing to worry about.

Reply to
carl mciver

HF even has sales with them under $10 quite often.

Back in the days before "dry charged" batteries you could walk into almost any servie station and see a rack of batteries wired up with a small pilot light (#47 ?) in series with each 6V battery. They didn't do that just for the pretty lights 8o). Lead acid batteries left setting sulfide up fairly quickly as well as self-discharging. I have a '62 Chevy pickup that doesn't get much use (

Reply to
keith bowers

My guess is that the battery became deeply discharged because some minimal loads were still drawing current.

What I do is similar to what searcher1 does, I just keep then on a proper (suto sensing) trickle charger. I have a couple of marine batteries.

i
Reply to
Ignoramus21796

"JR North" wrote: (clip) A battery will only discharge into a concrete floor if the floor is damp, and the battery has a conductive scum of electrolyte on the case. ^^^^^^^^^^^^^^^^^ If a battery has a conductive scum on the case, a small current can flow from the positive post to the negative, eventually discharging the battery. A concrete floor, or even a copper floor would not make any difference.

Reply to
Leo Lichtman

Any acid traces or residue on the bottom of the battery will etch any concrete it comes in contact with, doing severe damage to the concrete if there is very much acid. I think that's why we learned to not set them on concrete.

Reply to
Don Young

I am not sure of the chemistry or physics here but when I am trying to get a fully discharged battery to take a charge, I will hook a set of jumper cables to a good battery for a few minutes and then hook up the charger.

Reply to
Roger Shoaf

I'm writing Sears, suggesting that they change the name of their DieHard battery to DieSuddenly, Well-before-the-expected-lifetime-Battery. What an effing pita. And then they're gonna *pro-rate* it?????? Please.....

Reply to
Proctologically Violated©®

Thanks all!!! I'll get a charger and have a spare battery. I only gave the old battery 10 minutes on a charger, it was taking about 8 amps. I wasn't going to screw with it. Amazingly, the Town Car started instantly after sitting over two years. It might revive but I have a bud at a dealership that will just replace it without pro-rating it. DAMN, I love having friends!

Reply to
Tom Gardner

One of the small maintainece chargers works pretty well. Lift the negative ground clamp though. There are often Things in cars that keep a very low level drain on the battery. Clock, alarm etc

"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.

Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner

Reply to
Gunner Asch

I have one called a "Battery Minder" for my motorcycle and it works well. They have some additional circuitry in them that is supposed to help prevent sulphation in the battery. So far, it seems to work very well (I also have a

6 volt version I use for my gel-cell for my digital camera (I use external power when shooting the kids soccer games)). All secondary batteries will self discharge over time -- some faster than others. One important detail to remember (does not apply if you live in Florida etc.). A fully charged car battery (lead acid) freezes at something like -70 F, HOWEVER, a dead battery will freeze at about 32 F -- it is almost straight water when it is dead. It will freeze and split the case so keep those batteries charged in colder areas !!

mikey

Reply to
Mike Fields

A well-designed charger will maintain it. There's a lot to know about battery charging, that knowledge is incorporated in "good" chargers.

Batteries vary a lot in longevity, Interstate makes good batteries.

The bit about sitting on concrete once had basis but is now an urban myth. Having said that, it's easy enough to set the battery on a block of wood.

I replaced the batteries in my Ford cars after 8 years just because I thought I should, being in MN and all. The three batteries in my boat are now 5 years old, still work well. The boat doesn't get used between mid-October and mid-April.

Reply to
Don Foreman

On Sun, 11 Sep 2005 04:28:27 GMT, the blithe spirit "Tom Gardner" clearly indicated:

Consider a solar charger if your battery lives close to the sun. Why pay the Shrub's oil conglomerate any more money than you have to for energy? HF - $9.99 , JCW - $29.99

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Man, what happened to JCW's prices/selection?!?

Reply to
Larry Jaques

There is a little known phenomena called electrolyte stratification where a cold concrete floor can increase the self discharge rate of a lead acid battery. The bottom layer of electrolyte gets cooled by conduction from the floor while the upper layer stays basically at room temp. Since there is no natural circulation to mix the layers, the situation is static and the increased leakage current flow will eventually discharge the battery. Diesel-electric submarines had bubbler tubes in their batteries to agitate the electrolyte . The problem was potentially serious because the batteries were exposed to very wide temp. ranges in submarine duty. See

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Randy

Reply to
R. O'Brian

Interesting. Is that increased self discharge because the parts of the plates at different temperatures want to produce slightly different potentials so which forces a circulating current?

Jeff

Reply to
Jeff Wisnia

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