Hi,

I have a 2001 Dodge Ram 2500 pickup that I have unfortunately allowed to "set up" for a while. The battery is down, but it responds to a slow charge and builds up enough for cranking. However, it then apparently drains down again. I am still not using the truck.

I have not run the truck after a slow charge for any significant length of time to see if the battery will "re-charge." In the past I have thought that the way to build a battery up again is to run the vehicle.

Someone at our local "Mr. Battery" store tells me differently. He says a down battery will not charge again just from running the vehicle.

What is your take on this?

Thanks.

Car batteries are designed for high current and thus the lead plates are very close together. When you deep discharge these batteries for a long time, the plates short. The battery has a self discharge and there are systems that are always draining the battery in a modern car.

Take the battery out and place on a trickle charger. What your currently doing may destroy the battery.

The alternator will charge providing your above the voltage that makes the regulator work. I guess this would be about 8 V, but no confirmation.

MArine batteries are designed for deep discharge, but don't have high cold cranking amps.

Keepitsimple is right, you should use a trickle charger, but at the same time keeping the vehicle running does charge your battery. The battery won't charge completely but if you crank it and keep it running for a good while then it will be strong enough to crank up again and it will also charge while your driving, so you can charge it one good time to be able to drive it around