There are multiple tiers of batteries, I got the $50 one I linked but the first hit was $120 on their site.

So you can find the model’s battery here, and then google that and batteries plus. I have an 850M model which uses the rbc17 model. I’ve highlighted that on the apc site on this photo:

Batteries plus had a Duracell version of the one my APC unit needed, in stock in store so I could get it same day. If you’re in the US, might try them.

Which hardware is recommended? Trying to search through their list a ton of it is already on old-stable and seemingly ready to be eol-d. I’m not really interested in spending on new routers playing whack a mole with security updates every 2 years. I’d rather have poor performance and a longer lifecycle versus unknown likely marginal support window.

I use pf as the firewall on my server, what is the difference/reason for the opnsense fork?

They also list my current one as unsupported unfortunately, I think because of the Broadcom WiFi chip in it.

That was one of the things I was considering was whether running a router before the WiFi and then just using them as access points might be a better choice.

Realistically no. My wife primarily uses the ad blocking dns and smb file storage. I’ve built the server on FreeBSD so those should run near forever if I passed, and she knows she has until the server dies to find somewhere else to put her photos. Past that there’s a maintenance document next to the will, which includes everything up to how to replace drives on zfs, but I doubt she’d use it if I’m being honest.

Wife and I just bought them last year. Thankfully haven’t needed them but glad to have them if we do!

They also make airbag vests with built in neck protection, if anyone rides studies are showing an 89% reduction in cervical spine injuries, they are worth every penny!