APC pro 1300 charging voltage

Thread Starter


Joined Nov 15, 2020
Hello everyone I'm new here but here goes. I recently purchased 4 apc 1300s. I want to put lithium ion batteries in then but I need to either charge them separately. And thus deactivate the ups charger or boost it to 29.4v can anyone help me with this Please. I have limited knowledge, but the boards are labeled pretty well. I can not find any schematics.


Joined Jan 23, 2018
Have you checked the charging voltage of the unmodified UPS systems? That is, the open circuit voltage when they are powered up , and both with the batteries connected and not connected?
And what is the motivation for changing the battery type? I am not familiar with that particular model of UPS, although APC has been producing UPS systems for many years. So I am really wondering why change battery types.
AND, you will not be able to find a circuit schematic because they do not ever expect these units to be serviced, except for battery replacements.