APC Back-UPS After-market Battery Mod

[Anonymous user]

I have a 725VA (500w) Back-UPS which I modded with a new Amstron AP12-75 SLA battery using 10AWG wire (see attached pics for details).
The UPS seems to have problems calibrating the run time and it's only showing ~5min @ ~90% load. I tried a discharge for a few hours and the run time didn't change.

Any thoughts/ideas? Does it take a Smart-UPS to calibrate to an after-market battery?

P.S. I am running a Linux server with apcupsd and auto shut down / nologin disabled.

Thx!

[BillP · Accepted solution]

The UPS that you have is not designed to have an external battery connected to it. The battery charger might not be able to handle the required charging voltage of that battery. Unfortunately, I will not be able to provide any other feedback or help with your setup since the configuration that you have is an unsupported application.

Let's see if there are other Forum Posters who have been on the same situation as yours.