Fixing a low battery charger voltage on an SMT2200 UPS by interfacing with the smart protocol connector on the ups main board.



This is only known to work for me with the "ID17" hardware version. I tried on an ID18 and it did not seem to work, the USB serial adapter did not seem to be able to over-power the internal processor. It may be possible to cut a resistor to solve that problem as in the youtube video linked below.



Links for more info from others without which this wouldn't have been possible:

https://forums.overclockers.com.au/th...
http://jelmerbruijn.nl/apc-ups-smart-...
   • Finding the hidden Smart protocol in ...  


More info about the smart protocol commands:
https://networkupstools.org/protocols...