I have 2 UPS’ that have expired batteries. The manufacturers want crazy amounts of money to replace them, and a friend recommended I look online to see if I can get them elsewhere. However, the sites all seem so sketchy. Have any of you had good luck with third party battery sites? Obviously a bit nervous about safety.
Depends on the model, but many, especially cheaper ones, have standard lead batteries which you can buy at motor or electronics shops.
But do not use the “motor” ones for a UPS.
If their size and capacity is equal or similar, why not?
You should use the AGM variant (if lead batteries at all)