slow charging dead battery

[The_Jeff]

Just bought a grand marquis with a bum alternator, and a dead, couple months old NAPA/exide battery. This battery is a huge group size, BTW.

Got the battery home (will pick the car up tomorrow, 10 miles away, hope to run it off some stored juice) and it's trickle charging... 2 amps on my 6 amp walmart cheapie charger.

This battery was DEAD, and my typical experience is their internal resistance is low enough that it guzzles the amps from my nonsophisticated charger.

Shows 11.9 volts (and dropping while I look at it) when I take it off the charger, 14.4 volts with the leads hooked up. So it could be charging-- but it'll take several days at this rate.

Thoughts? Junk Exide? (but then I repeat myself) I have a spare walmart DT3N, their standard, smaller dual terminal setup that I'll bring as well for backup.

And yes I know it screws them up to deep discharge them but I figure once shouldn't totally do a new one in.

 

[Colt45ws]

See if NAPA will test/warranty it?

 

[alreadygone]

Should come back and be perfectly ok. But needs a HOT, high output charge.

Bob

 

[The_Jeff]

Hmm, sounds like the WM charger= fail.

It's up to 3 amps now, but charging voltage in the mid 13's.

 

[Familyguy]

The plates are probably all sulfated. Some of the more sophisticated chargers can coax that [censored] back into solution, but barring that I agree with a hot charge if you need to use it soon.

 

[Chris142]

Can you bump it up to the 6a setting? 6a won't hurt a thing.

 

[The_Jeff]

It's on 6 amp.

If I had a 20A mode I'd use that!

Good news is overnight it started taking around 4.5A or so and the surface charge is up to 12.6V.

 

[The_Jeff]

Epilogue, after 14 hours of charging at between 2 and 4 amps it started the car and got it 10 miles. Has been a consistent 4 amps since.