Is my battery toast?

Reply Subscribe

Thread Tools

Search this Thread

Sep 19, 2009 | 09:23 PM

Fubba

Thread Starter

Pro

Joined: Mar 2004

Posts: 686

Likes: 0

From: Southeast

Is my battery toast?

My battery has been dead for awhile...several months probably. It is completely dead as the key has been on. I hooked my new battery charger up to it in the car and out of the car, and the charger says that the battery is fully charged. It will not charge at all. Is my battery toast?

Sep 19, 2009 | 09:48 PM

7T1vette

Team Owner

Joined: Jan 2006

Posts: 37,637

Likes: 3,118

From: Crossville TN

Yes. You can rest assured that your battery is officially classified as TOAST!!! Leaving it ON for that long has turned the lead plates into mush and the only reason it shows a full charge is that it can't take ANY charge. Turn it in as exchange for a new one at Wal-Mart.

Sep 19, 2009 | 10:25 PM

Project80

Racer

Joined: Mar 2008

Posts: 428

Likes: 0

If the battery discharges and it falls below 6 or 7 volts level, it will need replacing.

Sep 19, 2009 | 10:31 PM

longbros

Burning Brakes

Joined: Feb 2004

Posts: 924

Likes: 2

From: Kearneysville West Virginia

Quote:

Originally Posted by Fubba

No, your battery may be ok. If it has not frozen, it most likely will come back to life. Leave the charger on it for some hours. Batteries that have been fully discharged and allowed to remain in that state for a long time, will not appear to take a charge at first. But, they will start out very, very slow, only drawing a few milliamps at first. Once the chemistry begins again, the charge will increase, and in most cases, will slowily increase to a normal charge rate. If after some hours, this does not happen, then yes, the battery may indeed be toast. I have brought many batteries back to life that have been discharged for long periods of time, as long as they did not freeze.

Sep 20, 2009 | 12:27 AM

7T1vette

Team Owner

Joined: Jan 2006

Posts: 37,637

Likes: 3,118

From: Crossville TN

Be sure to keep a fire extinguisher handy if following the above advice. If you ever get that battery to accept any charge, I would be amazed.

Sep 20, 2009 | 01:14 AM

Fubba

Thread Starter

Pro

Joined: Mar 2004

Posts: 686

Likes: 0

From: Southeast

I think it may still be under warranty haha. I'll see if I can dig up the receipt for advance auto. If not, I can do some brake work and keep an eye on it for awhile to see if ANYTHING happens. Thanks guys.

Sep 20, 2009 | 02:07 AM

73StreetRace

Burning Brakes

Joined: Aug 2005

Posts: 1,164

Likes: 1

From: Europe, France

Keep the charger at a low current ( the lowest possible ) during the first hours... The battery may wake up suddenly and the charging current increase rapidly

If there is still no charge after 6-8 hours, consider it officially DEAD

Last edited by 73StreetRace; Sep 20, 2009 at 02:10 AM.

Sep 20, 2009 | 01:33 PM

Project80

Racer

Joined: Mar 2008

Posts: 428

Likes: 0

Quote:

Originally Posted by Fubba

Leaving the key on for several months has discharged the battery to a point that the lead plates are totally sulfated. As the battery sat, the sulfate became increasingly harder and now has a high electrical resistance. Because of this, the battery shows a false reading when you try to charge it. True, with some batteries, it is possible under the right charging conditions to try to break the sulfate free and charge the battery. But, the battery could possibly overheat and explode.

I have personally seen batteries explode and I don't think it's something that you want to risk.
As already posted, the best advice is to buy a new battery.