@Tinnitus@lemmy.world, this is the answer.
The important part is that its giving clean power to your hardware, and it only needs to last long enough to shut down nicely. Batteries in these units are usually just car or wheelchair batteries, so you can get them cheaper just as a regular battery too.
You can also grab an older UPS with a crapped out battery for cheap and swap the battery. Last time I did that I got the UPS for $10 (local pickup) and put a new battery in for $20 from Lowes. Battery is still solid, its been about 5 years for that one.
If he becomes one, I’ll start having serious concerns about anyone developing a fs!