The Stovebolt Site Forums The Shop Area The Electrical Bay Bring a few months old battery back to life? What am missing here?

I left my running lights on with trickle charger on for about 5 days. Now the battery seems dead, won't take a charge. Shows less then 2 volts.

While trying to determine the problem, I did top off the cells with distilled water and didn't see any change. All of the battery plates were always under acid level.

What caused the battery to die? It was being charged, yet drained. Anything I can do to bring it back to life?

The 6-volt battery was only a few months old.

Thanks for your comments.
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I did the same with my New Truck, which I've done on pretty much every vehicle I own.

I hit it with the 12 Amp mode for a bit, then I'll leave it on the 2 Amp mode until it is fully charged.

Also, my trickle charger instructions say to have the battery fully charged when using it.

Many modern smart chargers won’t attempt a recharge from too low starting voltage
Make sure you have an old dumb charger when attempting to bring it back.

I was helping someone fix their broken charger one time
And half way through I figured out the charger wasn’t broken at all, they neglected to tell me that were trying to charge a dead battery and the charger was working as designed, lol
-s

The battery is "sulfated"- - - - -there is a thin layer of crystallized lead sulfate on the surface of the plates that must be broken down before the current will flow to rejuvenate the acid. Hit the battery with the "12 volt boost" setting on a commercial charger for a few minutes to force-charge the battery for about 15 minutes, then drop the charge rate down to about 10-15 amps overnight. Put a load on the battery such as a sealed beam headlight bulb and totally discharge it. Repeat that charge/discharge cycle several times. Eventually, the sulfate crystals will bvreak down and the battery will take and keep a charge. It usually takes a week or more of this process to reclaim a sulfated battery. A way to fool a "smart" battery charger into working with a totally dead battery is to connect two batteries in parallel- - - -one with a little charge in it. The charger will top off both of them.
Jerry

12 Volt Boost on a 6 volt battery ok?

Just keep the time short- - - -10-15 minutes max. If the battery starts to "gas" heavily or boil over, reduce the current.
Jerry

If you have a 1 amp or 2 amp trickle charger, not a battery tender, plug it up and let it go all day. It will probably come right back. Check the water in the vent caps and fill them up if necessary before charging.

If it's still under warranty, exchange it for a new one.

Had battery on charger overnight and appears to be coming back!!!

They usually do.

I brought a dead 2006 battery back to life in 2021. It was in a car in a climate controlled garage but hadn't been driven or started in 15 years. I topped off the acid and put it on a 1 amp charge for a day or so.

Excessive charge- as in charging a 6 volt battery at 12 bolts too long - is evidenced by a nasty sulfur smell.
This phenomenon is especially pronounced in desert conditions with temperatures in excess of 100f.
(Lesson learned in the era of the mechanical regulator.)