Tedd Thompson

I took the Old Man to lunch today and as I pulled out of the driveway I noticed the hood of his F150 in the up position. Seems he had left the key on and ran the battery down to flat nothing.After a short conversion I found out that the charger had been on that battery for about five days. There didn't seem to be a problem but will a extended charge (10 amps) do harm to a battery?....Just wondering...Tedd

drop top olds

For long charge times I always use a lower amp setting. From what I recall a low charge for a long time is better than a high charge for a short time. High current charges cause the solution to "boil" if I recall correctly. Actually it creates a gas maybe Hydrogen-Sulfate (?). I think its time to disconnect the charger and check to see if there is any solution left in the battery.

jensenracing77

10 amp for 5 days is not that bad. You should be ok. How cold was it when it was completely dead? If a battery goes dead then the acid will be water. If it was water and frozen then the battery is likely junk.

Fun71

Depends upon the charger. Automatic chargers will reduce the current as the battery charges so that the electrolyte doesn't boil. Mine is an automatic so I set it to the 10A range and leave it connected all the time; it drops to "battery tender" mode after full charge is reached..

Tedd Thompson

No freezing here, it was about 75 today here in the valley, we are in a major drought and it's more like spring than winter. Thanks all, i thought it would be OK but wasn't sure....Tedd

pogo69

That will depend on a bunch of circumstances , if you put a load tester on it and it passes your good to go

gregvm

Was it CHARGING(as per an ammeter) at 10 A for 5 days, or on for five days on a 10A RATED charger? If it was CHARGING at 10A for 5 days there is a shorted cell(s) and probably boiled those cell(s). Most modern chargers ramp down the charge rate as the battery fills. It will start out high if dead and over a few hours reduce to practically a trickle.


BTW, a COMPLETELY discharged battery(non deep cycle type) will NEVER return to 100% capacity. It damages the plates in the cells and will only return to about 85-90% capacity it had new.


Greg

rustyroger

You won't return the acid to water either. It will not be as strong as a fully charged battery, but it will still be very acidic.

Roger.

Tedd Thompson

I didn't check the setting on the charger, just pulled the wires off and started the truck, which started right up. I'll keep an eye on it for the Old Man. The battery looks dirty enough like it may be the original but I didn't check that ether...Tedd