How Long to Trickle Charge a Dead Battery?
 

My car has been down due to some mods I've been working on. Combined with some business trips, I haven't had a chance to drive it for about 4 weeks. Last weekend, when I went to open the car via the key fob....nothing. Completely dead.

I hooked up my trickle charger and it's been two days and it still indicates that the battery is charging. Does it normally take this long? The battery is a 1-year old AC Delcom OEM replacement. BTW, it's August in Florida, so lesson learned. :ack:

July/August in Florida is my "winter". Too damn hot to drive a vert.

Could indicate a dead cell....from being totally discharged. Try to charge another day or so and if that doesn't work, have it load tested to check for a dead cell. You may need to go shopping for a new battery.:thumbs:

Usually at 1 amp approx 10 hours

Are the setting right on your trickle charger? I know some let you change the amount of amps and the voltage of the battery. I left my lights on last week and hooked up the trickle charger and left it on for 2 days just to be sure that it got a deep charge. Does your car start up now?

Should not take two days to recharge. Might want to get the battery tested and see if it has gone bad.

You dont say which type of charger you're using. The "battery tender" type of charger takes longer to recharge the battery. i just recharged my boat battery (from dead) and it took 3 days - 1 day on a normal charger and 2 days on my Accumate.

:iagree: This was about the amount of time it took to bring back my discharged battery.
I had left the interior lights on our Grand Prix for 24 hours.
Just took it slow and easy with a 1.5 amp maintainer/charger :thumbs:

Thanks for all the feedback. I am using this 12V "Battery Tender Plus" trickle charger.

http://i499.photobucket.com/albums/r...teryTender.jpg

I hooked it up Sunday night and it's still not charged. The Key Fob is not unlocking the car and the hood light does not go on. Still completely down.

The charger does display the steady red light which indicates that the battery is charging. I've had the car down for over 4 weeks before and the battery never died, however it's been blazing hot the last few weeks here in Florida. I did remove the sun visors as part of the interior mod project I'm working on, however I don't think disconnecting the vanity mirror connections should have negatively effected the battery (per my other thread).

The battery is only one year old, so the warranty should cover it. Unless they have a non-use clause.

I've had the same problem

My Battery Tender will NOT charge a totally dead battery still in the car & hooked up to the car , I think because the computer(s), interior lights, hood light, and other stuff takes more than the trickle and it CAN'T catch up ...

I the past I used a regular 10 amp charger for a few hours to get some juice into the battery, then switched to the tender ... over night or longer

Worked perfect

Your results may vary ...

Thanks. I don't have any other type of charger (yet). Can I jump the battery and then switch over to the trickle charger?

Better yet - disconnect the battery from the car, then use jumpers, and let the jump stay on for 30 minutes or longer. That should put some life in the dead battery without effecting the vette electrics - then disconnect the jumper.

then re-connect the battery to the car

when you re-connect the battery to the car if you hear alot of clicking. the battery is still too low - maybe repeat but for a longer period ...

some may dis-agree with me, but I've done exactly that before I bought a 1/10/100 amp charger (with auto shut off).

Thanks. I will try that. Do you know if there is any long-term damage to the battery after it's recharged?

Don't know about your area but around here you can take the battery out and take it to an O'Rielys and they will put it on a tester for free (my favorite price !! :D ). Should be able to tell if you have a cooked battery or a dead cell.

Also, a CTEK battery charger is supposed to be able to recharge a completely dead battery still in the vehicle.

Years ago I did what you did (let the battery go DEAD), like 5 times in 3 years, didn't seem to hurt the battery, but eventually the battery needed replacement, anyway.

I never had any damage to the car or battery.

A symptom of a failing battery is it won't hold a charge for more than a few days (or less), and yours didn't have that symptom ... My guess is your battery is fine. Just don't let it go dead regularly - overall that's BAD for any battery.

A charger can charge forever and will never charge the battery if a battery cable end is loose or dirty. Are you going directly on the battery post with the charger clamps or just on the battery terminal ends?

Yep. Lessoned learned. I've had the battery run down before, however this is the first time it has been completely dead. Since the battery is only 1 year old, I'm hoping once I recharge it, everything should be OK. I will never let it go this long again, especially in the summer.

Once it is fully charged or if you buy a new battery, keep your tender plugged in if you think it is going to sit for more than two weeks. I keep mine plugged in pretty much all year round (not a daily driver) to make sure it doesn't discharge. There are a few ways to connect and dissconect the battery tender without the hassle of popping the hood every time (cigarette lighter, longer pigtail off battery, etc..)

Thanks for all the replies! I purchased one of these bad boys and completely re-charged the battery in 3 hours! Since it's still down due to the interior being reworked, I re-hooked up my original trickle charger which is now showing the battery as fully charged.

This new unit also has a maintenance mode with the digital read out, however it takes up more space than the trickle charger. I'm glad I have it around the garage. :thumbs:

http://i499.photobucket.com/albums/r...tuff/XC103.jpg

:cheers:

My experience with a battery tender and a dead battery in my 2012 Vette is that the car's passive electronics simply use too much juice - with or without a hood lamp and the alarm activated - for the tender to charge the battery. I've always had to remove one of the battery cables before attaching the tender - in which case I've achieved a full battery charge within 48 hours plus or minus a few (temperature may affect the amount of time required).

If you have the luxury of time. Try this before fussing around with trying to figure out if your battery is shot.