Charging flat OEM replacement battery at 4 AMPs
 

My battery sat for three months and it is obviously dead. I am charging it as we speak at 12v and 4AMPs. It has been charging for about an hour, and now the charger DC AMP meter is showing 2.25. I am not sure how long I should charge the Mazda OEM replacement battery at 4 amps. What is the AH and CCA rating of an OEM battery?

Isn't there a label on top of the battery?

Trickle charge it enough to get the thing turned over and then just let the alternator do the rest.. but deep discharging is not good for the oem battery. You might as well just buy a new battery, now's a good time anyway.

4amps? What a slow charger u got. Even 10 amp it takes couple of hours to fully charge it.

But if u let it sit for 3 month without disconnect then i would assume the battery is completely dead. Just buy a new one. Advance auto u can get one like 70 bux 3 yrs free replacement?

Yeah, its some old solid state 4 amp charger. I disconnected it after a month and it sat indoors for two months. Im just going to try charging it at 4amps for 10 hours, use it for a week or two if possible, then get a generic replacement.

Optima Yellow Top!

Charged it for 10 hours at 4 amps and it fired right up. Pretty damn good for something that was sitting for four months. Injected some 20w50 and premix into the housing via the spark plug holes prior to starting it.
Time to go battery shopping regardless.