From: http://www.stevejenkins.com/blog/2012/12/dead-ups-batteries-theres-a-cheaper-way/

1 . So whenever I remove multiple old batteries from a UPS, the first thing I do is 
shake them individually. If they rattle, they’re dead. Go ahead and toss recycle them (in fact, 
some battery stores will pay you for your dead RBC-style batteries). 
2. If they pass the shake test, I connect them to one of my CTEK 12 volt battery chargers (any 
car charger will do – car batteries are also 12 volts). If my charger doesn’t light up, it means 
the battery’s posts aren’t connected internally, and so the battery is dead. 
3. If the charger’s lights rapidly switch between “fully charged” and “charging,” then something’s wonky inside the battery, and it’s dead. 
4. But if it charges, and stays charged, put it in the “good” pile.

From: http://www.batterysharks.com/

From: http://www.gobti.com/

Very Expensive for UPS RBC2

From: http://www.gruberpower.com/12-volt-7-amp-hour-ah-battery

Great Specs and Crossrefernece tables

From: https://www.upsforless.com/cart.aspx

	
APC SmartUPS 750VA Tower UPS with LCD Display, Refurbished (SMT750)
For: 160.00 with Shipping