Getting a dead battery to charge?

**predator** · 03-05-2011, 11:18 AM

My bike battery is DONE... and my battery tender wont charge it (it acts as though there is no battery connected... I think i have heard that you can hook another battery to the dead one and trick the charger to charge the dead one...

Any one done it? Any tips or tricks?

-me

**Knight** · 03-05-2011, 11:23 AM

Have you checked the acid level in the battery? You could try replacing it, it may work. Obviously, be careful when doing so, as you are dealing with acid.
Otherwise, you'll need to replace the battery. I wouldn't recommend trying to "trick" a charger into charging a battery.

Oh, and make sure when charging that you have the charger hooked up correctly - the right polarity. I've caught myself hooking it up wrong.

**predator** · 03-05-2011, 11:52 AM

its a sealed battery... and the charger is hard wired into the bike... there are no polarity issues...

-me

**Knight** · 03-05-2011, 12:13 PM

Then I'd say you'll need to pony up the $ for a new battery.

**cammed goat** · 03-05-2011, 01:52 PM

I agree. I have tried to charge stone-dead batteries for customers and they STILL had to buy a replacement. I think of it as a 50-50 shot. You could try to charge the old battery...but the odds are you will need a new one.

**SteveCZ28** · 03-05-2011, 06:53 PM

some guys have to run jumpers to get a charger to charge a dry cell (optima) but in your case the battery is done for, and will need replaced. they arent priced too bad for the bikes

**9T8W66** · 03-05-2011, 08:15 PM

The run of the mill Home Battery chargers won't read or charge a battery that's below 10-10.5 volts. This is a safety feature so you don't hook up a 6 or 8 volt and blow them up.

**thearborbarber** · 03-06-2011, 08:33 AM

Hot magazine did an article last winter about this. They hooked up a 12v battery in parallel do the dead battery. Then the battery charger was hooked up to the pair. This revived batteries about 75% of the time.

**JayTA98** · 03-06-2011, 09:39 AM

be careful with this. If you are going to mess around with it wear googles. I will hate for the battery to blow up on ya. I seen it a few times. good luck.

**KMdef9** · 03-06-2011, 11:50 AM

What about the auto parts store as well? They might be able to get a charge on it.

Have you tried leaving a trickle charger on it for 48hrs our so? Keep at room temp.

**predator** · 03-06-2011, 02:56 PM

I have it going right now... we will see how it works... I left the trickle charger on it for prolly a week and it just acted like there was no battery tied to it... I will let you know if it worked...

-me

**9T8W66** · 03-06-2011, 03:50 PM

Originally Posted by predator

I have it going right now... we will see how it works... I left the trickle charger on it for prolly a week and it just acted like there was no battery tied to it... I will let you know if it worked...-me

refer to my previous post

The battery doesn't have enough voltage to be recognized.

**thearborbarber** · 03-06-2011, 04:33 PM

Originally Posted by 9T8W66

refer to my previous post

The battery doesn't have enough voltage to be recognized.

That's why hotrod used the second battery in parallel. To give the charger 12v.

**KMdef9** · 03-06-2011, 04:52 PM

Originally Posted by 9T8W66

refer to my previous post

The battery doesn't have enough voltage to be recognized.

Mine do, but mine aren't "run of the mill" I guess.

**parnelligq** · 03-06-2011, 05:36 PM

BUY a battery! I had one blow and its like a grenade. Not worth you getting hurt.

**JayTA98** · 03-06-2011, 06:09 PM

Originally Posted by parnelligq

BUY a battery! I had one blow and its like a grenade. Not worth you getting hurt.

Thank you!!!

**9T8W66** · 03-06-2011, 06:28 PM

We use constant voltage industrial chargers that will do 10 batteries at a time linked in series. I've seen them bring back a battery from 2-3 volts. Also one reason a Battery explodes is because of lack of water/acid in the cells and it builds up pressure because the vents are closed up. It sounds like a shotgun going off.
If it's a maintainable battery with caps you need to fill it before charging, if it's a sealed battery like and old Delco then it's done. I've seen old batteries read full voltage but have one dry or dead cell which causes them to not hold a load test.
I loop batteries for charging everyday and linking two batteries in parallel to trick the charger isn't something we do with regular lead acid batteries. This is how Optima's are charged when their very low though.

**Knight** · 03-06-2011, 06:35 PM

Originally Posted by predator

its a sealed battery... and the charger is hard wired into the bike... there are no polarity issues...

-me

As I said, it sounds like he needs to just get a new battery and be done with it.

**0rion** · 03-06-2011, 06:40 PM

first off...how old is the battery? If it's fairly old just replace it. If it's newer you need to get an initial charge on the battery prior to charging. With my battery charger I'll set it on "start" mode for 10 minutes or so and then try to get it to charge....usually works unless the battery is just done.

Side note: Several years ago when I was working at Coke I was putting a fresh battery into a forklift......36v battery that was roughly 3'long x 2.5'wide. Whoever had put the end on the battery left a little bit of exposed cable. When I sat it down in the forklift the cable shorted against the side of the lift causing it to arc and burn through the top of the lift for a few seconds and then it exploded with me about 2 feet from it. Took days for me to stop shaking and get all the shit cleaned out of my pants.