I am selling a 650 VA (Model # BK650MC) UPS. in very good condition. The battery is a EnerSys Genesis NP7-12, 12V, 7.0Ah. The internal resistance is 25.9 mOhms. A brand-new battery has a rating of 30 mOhms resistance so this battery strength is better than its rating. The runtime for a 40W load is 2 hrs. 17 min. The runtime for a 400W load is 6 min. 34 sec. (please see graph). The User's Manual is included.