On the right and bottom how the APC SmartUPS 1500 looked before cleaning. Despite APC claims of being non-spillable, lead acid batteries do eventually leak. APC just doesn’t tell you when (they say there is some fine print about replacing them, but hey – if the UPS doesn’t complain about capacity loss…).
Like I mentioned in my first post about the leaking, I cleaned the inside with sodium bicarbonate (easily to get – even in The Netherlands – as “baking soda” or “zuiveringszout” in most grocery shops. “zuiveringszout” is the same but much cheaper).
So after cleaning, you need to assemble a new battery pack and reinstall it. The RBC7 stock battery packs from APC are very expensive and since warranty expired on the UPS and APC batteries leaks anyway, it is much cheaper to re-assemble your own battery pack from a pair of UB12180 batteries. The same holds for the RBC55 (which are just basically two pairs of assembled UB12180 batteries). The decoding of these battery numbers are fairly easy: 12V holding 18.0 Ah of charge. Different battery manufacturers use different battery size nomenclature usually with a similar structure.
Disassembling and re-assembling the packs is fairly easy. Be sure to do this carefully: replacement sets of the APC battery connector wiring harness and fuse will set you back another USD/EUR 15-20 excluding shipping.
The below youtube videos are much clearer on this than any picture series I could have made, plus a series of Tweets figuring out the correct fuses to use.





