I read most of that, and am over here facepalming.
1) Applied Physics - Electronics Engineering ( AP1 ) - Specializations in Computer Science, and Information Technology.
Never replace a battery or anything power related. Without matching Specs, Voltage/Current. Preferably with OEM authorized parts.
UPS are I.T. Hardware related.
What you should have done from the start is replace the batteries using factory replacement parts.
Instead of cutting corners, tryna save a buck.
Luckily you didnt meltdown the replacement batteries you purchased. Or caused a fire.
They likely burned out prematurely from constant overcharging when at or near 100%.
Developed a " Memory " and only retained a certain portion of capacity.
Stick to modding linux builds.
Leave the I.T. stuff to the I.T. Professionals.
Thanks.
/TipsHat
-StealthMode