Converted UPS with two series of 48v to one?

[Chris Johnston]

I have a ACP UPS model SUA2200RMUS. It was having a problem that was telling the battery was not connected. The batteries were physically connected. I saw a video that seem to be similar to my setup and it stated that the unit should give off between 48 – 52 volts. I removed the pack and noticed the two series circuits. They were 4 batteries each. I was not getting 48 volts because some of the batteries are only outputting 11 or so volts. I tried just the batteries that were above 12 volts and setup one circuit that I tested for 48 volts. The unit came on and works without the battery warning. I plan to try to replace the missing 4 batteries when I can get what I need. The question I have now is there any problem with using the unit with half the batteries? I imagine it will only keep a power outage backed up for about half the time or less? Are there any other problems with doing this? Thanks

 

[Bluejets]

In theory, should be half the capacity as you stated.
In reality, they're probably well on the way out also so maybe just a fraction of the output time.