charging deaaaaad battery

Charging a battery that has sat 1.5 years through winter. Should I put it straight on 2amp trickle and let it sit for a few hours? It is a 10/2 charger.

Hook up a good battery via jumper cables and then hook up the charger on trickle. Leave it for a few hours and maybe the dead batt will take a charge. If it starts to charge, you can disconnect the good battery.

so it wont take charge on trickle alone? or depends on the condition ?

after a year and a half? Maybe, but I wouldn't count on it. I doubt that the charger will push a current through the battery, but the new battery might be able to.

got ya. Now im wondering if the gas in the jeep is bad lol

I'd put it on 10, and see first if it even registers on the ammeter. If it does not, leave it for some time and see if it starts to register. If it isn't taking some kind of charge within a few hours it probably won't. If it does, you might be able to squeeze some more life out of it, but don't count on much. But it should not do any harm to push 10 into it for a while.

If this is in a Cherokee with Mopar electronics, you will get bad running if you simply jump start a battery that is truly bad, because it doesn't filter the alternator output well. Mopars seem not to like that choppy DC. So don't get too worried if the Jeep runs ratty until you get a better battery into it.

Matthew Currie said:

I'd put it on 10, and see first if it even registers on the ammeter. If it does not, leave it for some time and see if it starts to register. If it isn't taking some kind of charge within a few hours it probably won't. If it does, you might be able to squeeze some more life out of it, but don't count on much. But it should not do any harm to push 10 into it for a while.

If this is in a Cherokee with Mopar electronics, you will get bad running if you simply jump start a battery that is truly bad, because it doesn't filter the alternator output well. Mopars seem not to like that choppy DC. So don't get too worried if the Jeep runs ratty until you get a better battery into it.

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I don't know about the life expectancy. I have had really good luck reviving Optimas that were left sitting around. One has a date sticker of 02 pulled as defective at a parts store I worked at. sat for a year. revived this way and its been in my DD ever since.

Of course your milage may vary, but sometimes they seem to come back fine. Worth a shot.

A battery that discharged may take 24 to 48 hours to recharge fully.
Charge it at 2 amps and check it every 6-8 hours.(Case temperature and water level if possible) It might be shorted out after sitting that long.
Batterys do not like the heat of a fast charge & you do not know the condition of it after sitting for that long of a time.
As for a dead battery in a Jeep, the alternator at idle does not provide enough voltage to keep the electronics going right after you jump start it. It will need time to build up the charge.

Ricker said:

A battery that discharged may take 24 to 48 hours to recharge fully.
Charge it at 2 amps and check it every 6-8 hours.(Case temperature and water level if possible) It might be shorted out after sitting that long.
Batterys do not like the heat of a fast charge & you do not know the condition of it after sitting for that long of a time.
As for a dead battery in a Jeep, the alternator at idle does not provide enough voltage to keep the electronics going right after you jump start it. It will need time to build up the charge.

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I think it should still be enough at idle, and the electronics will continue to run pretty well below 12 volts, as I've found out when my alternator packed it in. But the output of an alternator is AC, which is then rectified by simple diodes into a pulsating DC. If the battery is not taking a charge, it is also not supplying voltage to fill the gaps in the pulsating DC, and that lack of filtering makes some electronics unhappy. I think you'll find that this occurs well above idle speed on some systems.

I remember back in the late 50's or early 60's, when Chrysler first introduced alternators in their vehicles, one of their marketing gimmicks was to demonstrate how you could drive without a battery, something a DC generator could not do because of its low output at idle. Of course there were no electronics to worry about then, and you could simply take the battery out of the circuit. I vaguely recall that they drove a Valiant or something across country without a battery.

Fully charge it, if it will charge, (Low rate many hours).

Then let it sit a day or two to be sure it is holding a charge.

Only then put it into the Jeep.

Good Luck,
Orange

P.S. Replace it if there is ANY doubt, as a tow costs more than a battery. (And you still gotta get a battery!)

Maybe I'm different, but the cost of a battery is a few tanks of gas. With the trouble they can create when they go bad at the wrong time I rarely wait until they die. I watch the warranty period. When they get within 6 months of the end of their warranty life I drive over to Sears and have them drop in a new die hard. I just consider it part of normal maintenance and the practice saves me a ton of trouble in the long run.

yardape said:

Maybe I'm different, but the cost of a battery is a few tanks of gas. With the trouble they can create when they go bad at the wrong time I rarely wait until they die. I watch the warranty period. When they get within 6 months of the end of their warranty life I drive over to Sears and have them drop in a new die hard. I just consider it part of normal maintenance and the practice saves me a ton of trouble in the long run.

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For my wife and daughters' cars, absolutely.

For my woods toy? if I can save a nickle on one thing, i can spend it on another.


from the optima website:
(works for regular batteries too)
How do I charge a deeply discharged battery?

If an OPTIMA is deeply discharged (below 10.5 volts) most basic chargers will not supply a charge. Also keep in mind an OPTIMA will not recharge properly if treated as a regular flooded or gel battery. To charge the battery, you can wire a second fully charged automotive battery (12+V) to the discharged AGM in parallel (+ to + and – to –). Then hook up the charger to either battery, setting the charger at 10 amps. Leave for two hours, monitoring frequently. During this process if the discharged battery gets very hot or if it is venting (hissing sound from vents) then stop this process immediately. When the discharged battery reaches 10.5 volts or more, remove the standard battery and continue charging the AGM until fully charged.
For normal charging a relatively low current, such as one or two amps can work well, but when the battery has been deeply discharged, some sulfation of the battery plates may have occurred. If you charge at 10 amps, the higher current will help to break up this sulfation.
If you have an automatic charger, let it run until the charger indicates charging is complete. If you have a manual charger, you can get a rough estimate of the charging time in hours of a completely discharged battery (11.2V) by multiplying the capacity (amp hours or Ah) of the battery by 1.2. If your battery is not completely discharged the time would be less.
In most cases these steps will recover the AGM battery. It’s okay for the AGM battery to get slightly warm during the charging process. If it’s hot to the touch it means there’s a short and the process should be discontinued.

Just out of curiosity did this dead battery sit outside over winter? If its a standard lead acid battery they will freeze if they are not charged. It can break the plates apart and cause a short internally which ruins them. If it has removable vents pop them out and look in the top with a light for damage.

Bigdaddyyjlove: Thanks for the tip on the optimas. I have 2 reds wouldn't take a charge. I'm definately going to try this out and see if I can save them.

You can get by with a lot of crap on batteries as long as they aren't pushed very hard.

Add cold temperatures, old starters, lots of short trips, and a marginal battery is going to bite you in the a**.

OP you say EAST COAST--would that be Florida or Maine?