Swapping the battery in a small UPS
The UPS under the desk started beeping during its weekly self-test. The sealed lead-acid battery inside was five years old, which is about what these last.
What I did
- Unplugged everything and let it sit for ten minutes before opening the battery door.
- Matched the replacement by voltage, capacity and terminal size (12 V, 7 Ah, F2 terminals).
- Moved the leads one at a time so the polarity could not get mixed up.
After a full charge the runtime estimate went back from three minutes to about twenty. The old battery went to the recycling point at the hardware store.