Buying a used OE AGM battery

[0_to_60]

Thinking of grabbing a oe battery less than a year old for dirt cheap; hasn't been used for months. Owner says the battery is fully charged and can hold a charge and will verify with me at Autozone. Is this a good idea in general? I know used batteries are a gamble but what do you guys think of AGM that has been laying around for a while? Should i pass?

[pbonsalb]

If it is half new or less and the owner has kept it charged, definitely.

[aus]

Has it been trickle charged? My battery died under warranty even with the car being driven daily.

[0_to_60]

i dont think he kept it on charge after he sold his car. He had it laying around and recently charged it to see if it works

[Helmsman]

Easy enought to check if its good. Start with measure voltage as is and see if it keps the 12.7 isch (or whatever for this type batt when full), then add some load (wire a light bulb or something). If it holds voltage with a slight drop you're good to go mate.

[brownb_2]

if you can afford to buy an M3 you can afford a new battery

[Helmsman]

Originally Posted by brownb_2

if you can afford to buy an M3 you can afford a new battery

Que, why not use stuff as long as possible instead of throwing away...

[brownb_2]

Originally Posted by Helmsman

Que, why not use stuff as long as possible instead of throwing away...

completely agree, if it was already yours..

[0_to_60]

Thanks for the replies, What do you guys think of load testing the battery? I have done this test before and it was pretty accurate

[Helmsman]

Eh...yes sir, as mentioned above I believe this is a good idea.

[0_to_60]

Update: Ran load tests on the used agm and it held up really well not losing any current or significant voltage, i let is stay on charge on agm mode for 3 days and ran another load test same response battery good condition. So its finally in the car. On the other hand my old battery that i took off from the car responded lightly weak to load tests and lost voltage after the tests. I let it stay on charge for days and it responded again with voltage drop. What was really interesting was how my old battery would charge really quick to full compared to the used agm

[dparm]

Originally Posted by Helmsman

Que, why not use stuff as long as possible instead of throwing away...

Agreed! Just because it's an expensive car doesn't mean you need to be perpetually spending tons of money on it...that's what the aftermarket companies love to perpetuate.