chilidip

So I bought a battery from Wal-mart for his AP1 in March of this year. He basically didn't drive it for 6 months so it went dead. We jump started it on Wed (ran fine) ran the car for about 30 mins while driving it for 5 mins. Was this enough of a charge, or do you think the battery is no longer good? Reason I am asking is I believe the battery has a one year replacement warranty.

Status of the battery prior to jumping.. the charge was so low, you couldn't get the keyless remote to open the car.

Status of the battery now: electrical functions work, however not enough to start the car.

Should I get a replacement or charge the battery fully (drive it for an hour.. or get it charged at autozone).

Thanks!

Fusiondynamics

Since there is warranty, I would opt for the replacement.

chilidip

Ok, thanks

Bror Jace

Definitely charge the battery fully, first, before going for a warranty replacement.

It's not the battery's fault the car sat for 6 months. That would drain most batteries.

fatjoe10

Also, remember that a battery that sits discharged for too long gets "sulfated," reducing the life of the battery over time. It may work now, but there's a chance that it won't last 5-6 years like a normal battery should.

In my personal case, I had a car put away for 8 months that had a fully charged, fresh off the shelf battery. Battery was dead when the car came out of storage. It was fine but the battery failed me within 3 years.

If I was you, I'd get a new one if possible.

EDIT: Also, have the battery fully charged by a charger and not by the alternator. Alternators are not designed to charge a completely dead batt. Doing so may result in ALT failure.

idea-catalyst

There are a lot of easy tests for battery condition, but they require a volt meter (a digital volt meter is available from Radio Shack for less than $20). The basic test is: charge the battery fully (not 20 minutes on the alternator, but overnight or for up to two days on a trickle chargers); let the battery sit for at least 12 hours with no load (although there is a slight load from being connected to your S2k, it is not significant for 2 days); measure the battery voltage at the battery terminals. If the battery is less than about 12.5v, your battery is toast because the nominal drain from electronic standby is only about 40mA and your battery had better be able to handle this for days or weeks (but probably not months).

The other test is when the engine is running. Factory specs call for alternator output of about 13.4v to 14.5v (I forget the exact numbers, but this is a good range). If the alternator doesn't boost the battery voltage up to at least 13.4v, then there is something wrong with your charging system.

As fatjoe10 noted, batteries can become sulfated - there are maintenance chargers that help with this condition (search batteryminder) but you really don't want to leave your battery "dead" for long periods of time; lead acid cells don't like being discharged.

Bottom line: there are very few automotive batteries that will tolerate being "left alone" for 6 months, particularly if left connected to the constant drain of most current vehicles. If you need to do this on a regular basis, find yourself a good "maintenance charger" that will meet the constant needs of your vehicle's electronics and also keep the battery up without overcharging it. Many years have passed since "turning off" your car really meant "turning it off". Electronic processes persist.

chilidip

Thanks, that's a lot of good information. I have this charger at home.. will this suffice to get a full charge?

http://www.sears.com/shc/s/p_10153_12605_0...ku=02871227000P

I'm still a little wary in trying to get this battery up to full cahrge.. in the event that it is now bad..

hirev

i just left the ignition on in my acura for 24 hours, stupid...i was doing something with phone and nav....so no start...i jumped it and within 10 min of just ideling it started on it's own....i think if a battery cannot come back in a few min of driving then it is not in good shape...i bought the battery within the past year....i have one of those portible jump starter/tire pumps from costco, well worth it...i am carrying it in my trunk today incase the car does not start after sitting for hours.

idea-catalyst

If you are lucky, running the car for 10-15 minutes may charge up the battery sufficiently to start the car the next time. If this happens, then over your next few drives, your battery may come up to full charge - but it won't happen right away. Typical auto batteries are 40-60 Ampere Hours and your charging system will not charge the battery at a sufficiently high rate to restore it to full charge in a short period of time. And you wouldn't want to because your battery would likely overheat, warp the plates, destroy itself, and possibly explode.

A better plan is a smart charger that starts out at about 8 amps and slowly reduces its charge rate over 24-48 hours to restore full charge. The "BatteryMINDER" that I'd mentioned in my previous note is a charger that also de-sulphates batteries. I don't have a lot of experience with this charger, but I'm currently experimenting with two of them and the initial results look promising.

Anyway, think "slow/trickle charge" to get your battery back up to full charge.

chilidip

Thanks all! given the battery charge I have, are there any indications I need to look for? Just slow/trickle charge it over night?