Server equipement

I've picked up many battery backups that were in good shape and some that were new in the box. The problem is how old are they and how long have they been sitting in storage. From what I've been told batteries not being charged do not last long. I don't know if that's true but I do know that replacement batteries are very expensive. In most cases you can buy a brand new battery backup with new batteries for just a little more than replacement batteries.
Plug them up and test them. You might want to check the batteries and make sure they're not swollen or cracked first.
If they hold a charge and work you can probably sell them.