Hello, On 21.09.2019, I changed the RBC6 battery in an APC SMT1000I UPS. No particular problem. Best regards.

The replacement battery as listed on APC's website for the SUA1000i is the RBC6, so yes it does. It is also why we purchased this one, we have the same APC UPS!

Instructions are enclosed, as far as I can remember. But it is quite simple and can be done during operation. Remove the front cover, unscrew two screws and remove the metal plate, pull out the battery, remove the cable (there may be a short spark here), remove the old battery. Now do the same steps in reverse order and you are done. Be careful not to press a button at the front or cause a prolonged short circuit.

According to my information, you need the RBC113 battery. Unfortunately not available at Digitec.