Used 9 cell battery

[WVZR1]

I've an opportunity to purchase a used 9 cell for a T60 and we're a few $$'s apart between ask and offer! What exactly do I want to check when the battery is installed? How much does age have to do with "real value"? How does one base value on battery cycles etc?
I've tried some searches with no "direct information"!

Battery is a 42T5245. I appreciate any "advice"!

[SHoTTa35]

check the "remaining capacity" the cycles almost mean nothing. I can cycle a battery 10 times and not loose any capacity but after 1 cycle battery can loose 10 percent (reconditioning)

[DAH]

I would suggest that you go to Lenovo Battery recall page and check to see if it's been recalled and replaced under that program. Remaining capacity should be equal or near full charge capacity.