Car Battery won't charge after sitting for a Year

Question

I have a main starter battery and a leisure batter in my van. They have been left unused for around a year with my van off the road. I am now trying to get it up and running however I am unable to charge either battery.

The main battery is around 14 months old and the leisure is around 3 years old.

I have a main charger which I have connected, however the charge gauge does not move when I connect the positive and negative leads to the batteries. When I touch the positive and negative leads together, they spark and the charge gauge moves. I therefore believe that the charger is working OK.

Could there be something wrong with both batteries that is not allowing the current to flow around the battery from positive to negative and therefore stopping them from being charged?

Any ideas would be greatly appreciated. Thank you.

Answer 1

I assume the battery is completely dead? Multimeter not showing anything?

There are a couple of chargers that will try and revive a battery (Accumate/Optimate for example) that's pretty much completely dead, but your average parts store charger needs some charge left in the battery before it'll work.

Even if you get the batteries recharged, you've already severely shortened their lifespan unless they're deep discharge batteries. In fact you might already have ended up with two large paperweights but I'd still try to recharge them and see what happens.

If you're storing batteries for longer than a couple of months I would suggest that you'll recharge them from time to time or hook them up to good trickle/float charger (not the 4.99 special). These batteries really don't like standing around discharged.

Answer 2

There is an option for attempting to recover a completely dead battery described defined on Optima's website.

From: http://www.optimabatteries.com/product_support/resuscitating_agmbattery.php

Recovery Option #2: The DIY Solution

This is a recovery method for the do-it-yourselfer using the equipment you've got in the garage. With this option, you're going to trick your charger into charging the deeply discharged AGM battery.

Here's what you need:

• Battery charger
• Jumper cables
• A good battery, preferably above 12.2 volts (It can be an AGM or flooded battery, it doesn't matter.)
• The seemingly dead, deeply discharged AGM battery
• A watch or timer

Now, here's what you do:

1. Hook up the good battery and deeply discharged AGM battery in parallel—positive to positive and negative to negative. Do not have the charger connected to the battery or turned on at this stage.
2. Now, hook up the good battery to the charger. Turn on the charger. The charger will "see" the voltage of the good battery, and start providing a charge.
3. After the batteries have been hooked up for about an hour, check to see if the AGM battery is slightly warm or hot to the touch. Batteries naturally become warm during charging, but excessive heat may be an indication that there really is something wrong with the battery. Also discontinue the process if you hear the battery "gassing"—a hissing sound coming from the safety valves. If it's hot or gassing, STOP CHARGING IMMEDIATELY!
4. Check back every hour to see if the AGM battery has charged to 10.5 volts or above. If it has, disconnect the charger from the wall outlet and remove the good battery from the charger. Now, connect only the deeply discharged AGM battery to the charger. Turn on the charger and continue until the AGM battery reaches a full charge, or until the automatic charger completes the charge process. In most cases, the AGM battery will be recovered.