I have a stock AGM bagger battery that was removed from a 2016 bike a year ago. The battery was six months old when pulled, fully charged, set aside and forgotten about. Yesterday, I checked it and it read 11.9v after sitting without a charger for that year. I put a 3amp battery tender brand charger on it, and it read fully charged after several hours. After sitting overnight off the charger it reads 12.45v.

Could the the battery be ok after sitting for that long?

I picked up a 2015 that has an aftermarket battery and I noticed the neg terminal is cracked, so I’l like to use this battery if possible. What do you think?

 

Have it tested to be sure. If it was never completely dead it should be fine. These batteries don't sulfate like traditional lead-acid types.

 

 

If it took hours to fully charge, it's probably ok. It's when they charge up in 5 minutes that the battery's toast, they'll discharge just as fast, no capacity left. Putting the battery through a few work cycles sometimes recovers capacity, too, you may see the resting voltage increase some more after a few rides.

 

Put it on and try it!

 

I did, it seems fine (post 3)

Tx

 

Phew, that's a relief!