Dead battery not charging

[Kon]

Someone parked the car in the garage with the door slightly ajar and now the battery is completely dead.

I have a Schumacher smart charger that's supposed to automatically switch between 6V or 12V. It thinks my Genesis battery is 6V for some reason, probably because it discharged so low. I left it charging overnight and the car is still completely dead -- not even enough power to turn a light on.

Is the battery toast or should I get a different charger?

 

[joegr]

Completely discharging a car battery does damage it. If your battery is three years old or older, I would go ahead and replace it. If it is younger than that, you could take a chance on it. I think that you need a dumber, more manual battery charger to be able to charge a deeply discharged battery.

Note also that some auto stores will load test your battery for free. To do that, they have to charge it up first (they have high-speed chargers). You could give this a try.

 

[Kon]

Completely discharging a car battery does damage it. If your battery is three years old or older, I would go ahead and replace it. If it is younger than that, you could take a chance on it. I think that you need a dumber, more manual battery charger to be able to charge a deeply discharged battery.

Note also that some auto stores will load test your battery for free. To do that, they have to charge it up first (they have high-speed chargers). You could give this a try.

Is it easy to get the battery out of the trunk? I'll try a simple 12V charger first but the battery is barely 1 year old so I don't want to buy a new one yet.

 

[Suburbazine]

You need to use a dumb charger or a 12v fixed trickle charger to bring the battery up to at least 10.8v before any "smart" charger is going to charge it. Only use low amperage modes (less than 5A) to bring it up from dead to prevent outgassing.

The Schumacher chargers are usually pretty crappy anyway and should only be connected to lawnmowers. Never connect them to a modern car for any reason (especially NEVER in BOOST mode!!!!!) if you like your wallet full and your car not broken. If you're determined to use one, make sure it's connected to a battery that's NOT connected to the car too.

Stuff designed to not blow up car electronics while charging usually costs a lot more, like this:

PSC60 - XS Power

MSRP: $459.99 Our brand new, redesigned PSC60 IntelliSupply will be available soon! Power Supply, 60A, 12V, 14V, 16V with AGM Charge Mode – Sleek On-Board Design – Remote LCD Display – Three Mode Operation – 120VAC (100~130VAC) / 230VAC (180~240VAC) AC Input You can view or download the PSC...

4xspower.com

 

[carguy75]

Someone parked the car in the garage with the door slightly ajar and now the battery is completely dead.

I have a Schumacher smart charger that's supposed to automatically switch between 6V or 12V. It thinks my Genesis battery is 6V for some reason, probably because it discharged so low. I left it charging overnight and the car is still completely dead -- not even enough power to turn a light on.

Is the battery toast or should I get a different charger?

Same thing happened to my battery recently. The battery was 4v. My Sears auto charger would max out to about 6v in 10amp fast charge mode when using battery terminal under the hood..

I had to enter the trunk and remove the negative battery cable and then connect the charger directly to battery itself without it being connected to car electrical system. The battery quickly started to charge pass 6v when directly connected to the charger until fully charged. So far so good.

 

[Husam]

C

Someone parked the car in the garage with the door slightly ajar and now the battery is completely dead.

I have a Schumacher smart charger that's supposed to automatically switch between 6V or 12V. It thinks my Genesis battery is 6V for some reason, probably because it discharged so low. I left it charging overnight and the car is still completely dead -- not even enough power to turn a light on.

Is the battery toast or should I get a different charger?

Check the alternator too.