DIRA: Low Voltage Battery Alarm Unit
The main problem in the battery string is a finding “the weakest link”. When you have up to 16x12V batteries (4 parallel strings 48V) or up to40x12V batteries in the UPS – it’s a difficult to find bad battery. Your Power System or UPS controls only Group (String) voltage. During discharge in the battery strings some of the batteries can goes down less than 10V.
Your UPS does not see that while individual 12V batteries destroy internal structure. Voltage level less than 9V for SLA (VRLA) batteries is a critical. And we need to know which batteries are. You need to check them more attentive. You may use discharge unit or MIDTRONICS tester or both for that.
Low voltage battery alarm unit is a simple and very reliable battery monitoring unit for DC power systems (Telecom and Power Utility) or for UPS based on control individual 12V batteries in the battery strings.