Battery (auto) low voltage limit

I've got two auto batteries that are reading between 6 and 7 volts. They have been on a wood floor, indoors, for a couple years. I've got a trickle charger on one of them. See if it will hold.

The fact they got this low -- does that suggest they are worthless, now?

Reply to
Stormin Mormon
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Not necessarily. See what happens with the trickle charger. If they come up to around 12.5 volts, and stay there for a few days after being removed from the charger, they're probably going to be ok -- but if you're going to use them in cars, you might wanna keep a set of jumper cables in the trunk. Of course, that's a good idea anyway.

Reply to
Doug Miller

they may not come back up. if they were never used you have a better chance. the thing about not placing a battery on concreat only wood is not true.

Reply to
GVecere

Below 50% 70% charge lead acids sulfate fast. Its best to keep full chage , what percent capacity you have left can be determined with a load test, im sure you lost alot. Charging to 14.5- 15.5 can cook some away. Have them tested after you charge them they could be worthless.

Reply to
m Ransley

You won't know until your have tried. It will not cost much to charge them.

BTW with today's batteries you don't need to worry about wood, or concrete etc. floors. It is no longer a problem.

Reply to
Joseph Meehan

"Stormin Mormon" wrote in news: snipped-for-privacy@uni-berlin.de:

They probably are heavily sulfated,and will not maintain voltage under load,even after charging. I suggest trying a Vector brand charger,they are supposed to be able to renew sulfated batteries.

Lead-acid batteries do not like being left unused for years,without any charge/discharge cycles.

Watch out (while charging) for hydrogen gas,it can cause an explosion.

Reply to
Jim Yanik

They might be ok. You need a hydrometer to see what is happening in all the cells (if they have caps)

This site tells you more than you need to know about batteries:

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Reply to
HRL

dont waste his time Stormin your gettin Trade Junk For Junk

Reply to
m Ransley

Reply to
George E. Cawthon

I was present at a battery explosion one time. The old farmer was in a hurry, was charging a piece of farm equipment with a BIG charger, and had it on 12 volt boost. He leaned over and undid one of the clamps, and the spark was enough.

I may never forget his next words "get some water for my eyes". I grabbed him, and the two of us dashed into the house. There was acid all over his coat, and I got plenty on my coat.

Most of the front of my coat fell off the next day, I still have the coat. It was an old military style green jacket, people ask if I was machine gunned.

Trickle charging is not likely to be a hydrogen problem. But thanks for the reminder.

Reply to
Stormin Mormon

That was my guess. I'll leave the trickle on over night and check the voltage in a week or so. But I'm guessing they are useless.

I took a battery to the scrp yard last year, it got $1.25, a couple days ago one brought $0.50, hardly worth the gas to drive it there.

Reply to
Stormin Mormon

put it outside and plug it into 110v , cook it awhile , yeee ha. Cook off that sulfate. boom......

Reply to
m Ransley

Your farmers Blow was 99% caused by Reverse charge. i id it , bad cabel color. Reversed..........

Reply to
m Ransley

This is Turtle.

If you charge the batterys for 1/2 hour and then pull them off the charger and read the voltage of both. If you get less than 11.9 volts there gone. If you read 12 volts or above 12 volts they made it. A perfect battery dead or fully charged should read between

12.1 volts to 12.6 volts.

TURTLE

Reply to
TURTLE

A good battery explosion story I fully charged a battery on the bottom shelf of a work bench with a vice mounted to the top of the bench about 2' up. About

3-4 weeks later we had completely forgotten about the battery and a few boxes of other junk had buried it. The guy who worked in the bay next to mine was cutting a steel stub axle mounted in the vice with a die grinder and making a good trail of sparks. BIG BOOM it took us about 5 min before we realized where the BIG BOOM came from. Regards Gary
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Storage Sheds for the NY tri state area
Reply to
Gary

Just because the OCV, no matter how battery has sat, is reading "between 6 and 7 volts", that shouldn't be the sole reason for condemning a 12 volt lead acid battery as unusable, junk or scrap.

The O.C.V. (Open Circuit Voltage) only indicates the percentage state of charge.

Be careful when the OCV is below 9 volts, you may damage some chargers by trying to recharge a battery that reads 9 volts OCV and below.

A OCV voltage reading below 10.75 volts indicates the battery is Zero (0%) percent state of charge

CAUTION WARNING: A battery expels MORE Hydrogen gas from a discharged battery than one that is charged.

A trickle charge (especially on a constant current charger) may be worth a try. If the ammeter isn't bouncing around and no smoke is evident, try to continue charging. Don't be surprised that it may require 16 to 24 hours of charging on a 10 to

15 ampere charger.

Hopefully, after 16 to 24 hours and once battery is removed from charger, the battery has attained

100% state of charge.

If you want to terminate the charge for any reason: 1) Unplug or turn off the charger and 2) Disconnect the charger leads from the battery. 3) After removing the battery from charge, leave battery sit and "cool down" for at least 72 hours. The OCV is unstabilized due to a surface charge once the battery attains full charge. 4) Wait for 72 hours for surface charge to bleed off. The surface charge won't become stabilized until at least after 72 hours.

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Reply to
charge

the voltage of both. If you get less than 11.9

battery dead or fully charged should read between

Don't forget temperature compensation. 12.6 is a little low for a full charge. My deep discharge batteries read 12.75 at full charge at

75 degreees. So does my truck battery. OTOH, my Explorer battery which is now 10 years old (original battery) won't charge past 12.55 V, so I know that it isn't working perfectly. OTOH, how many batteries last 10 years; this is the first for meas most have died after 5 or 6 years.
Reply to
George E. Cawthon

read the voltage of both. If you get less than

11.9

battery dead or fully charged should read between

This is Turtle.

What i was saying here is to charge the battery for about 30 minutes and then pull it off the charger and read the voltage. It should not go under 12 volts at that time or you have a dead cell. For a good battery. It will read between 12 and 12.6 volts at that time. 12 volt being a weak battery but still useable battery but 12.6 volts or so a good battery.

TURTLE

Reply to
TURTLE

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