I have an 1985 Sears 2/8 amp, 12 volt battery charge that I originally bought. I've only used it twice or so. It's been in the box in and looks to be in good shape. Should I used it to charge a totally dead Sears Platinum Diehard? This battery is completely sealed so no water to add.

Will the charger be OK to use and not burst the battery? Don't know how the gas can vent so that is my concern.

Regards
Larry

 

It is vented.

No reason not to use that charger.
It is going to take a long time

 

How long will it take on the 2 amp setting vs the 8 amp setting? Just asking for a reasonable guess.

I figured it had to be vented, but I don't see anywhere to add water. Maybe I will take a closer look now.

Thanks,
Larry

 

You say it's completely dead.
Most battery's will never come back from that.

How many amps and what group size is the battery?
Without a load test to tell you how dead your battery really is there's no way to know. (How long)
10 hours @ 10A = 100Ah.

Your best bet is to monitor temperature and voltage.
stop if the battery gets too warm or when it reaches 14V right after disconnecting the charger.
A healthy battery is about 12.5-6V at rest (hours after the charger is disconnected)

 

I didn't drive my truck for two days and i tried this morning to start. It was the deadest I've ever seen a battery. Not even a clicking sound. I took the battery out and it tested zero.

I didn't think running it to zero would totally kill it. I have a three year warrantee on it.

Numbers on SearS DieHard Platinum say
930 CCA / 65
135 RC /50065

Regards,
Larry

 

Will be fine on the 8 amp setting. You'd have to neglect the battery for a couple days or more to cause trouble.

It helps to monitor the voltage and keep an eye on things, though, and compare with the AGM battery charge chart at

http://www.batteryfaq.org

8 to 10 hours sounds about right. Even better, monitor the current. Remember it takes roughly two volts over the normal resting battery voltage to charge a battery. So it will start out with about 8 amps and very little voltage. Watch the voltage track the chart at the site linked. Pretty cool huh? As the battery charges the amps decline to just a fraction and the voltage tops out somewhere around 14.5 to 15.5 volts depending on temperature, battery is fully charged. Put it on a timer to be safe.

 

Please delete

 

Did you leave the lights on?

I'd be more concerned about what killed the battery, than the fact that it's dead.

 

Please delete

 

I'm looking into that now. BTW, Sears charged the battery for me and said it was "good." So I'm off to see what the real problem is. There's been a slow drain on the thing for years and I can't find anybody who knows how to trace it.

Maybe this time it will show up better.

Regards,
Larry

 

Sears gave it a quickie charge. An overnight slow charge is adviseable. It's possible to overcharge a battery but ya really have to go out of your way to do it. Particularly after it has been discharged completely.

 

Please delete

 

OK, never thought of that. I'm going to try it. Unfortunately, I do rely on this truck for my only transportation.

Regards,
Larry

 

New battery in 2015 F150...dead...F150 not driven since 8/6/2015 (I've been ill).

Ancient trickle charger hooked up, it might be ready by this time tomorrow.

 

Slow charging is the way to go.

Glad to see you back Bill!