Yet another reason for me to dislike Shopify.
I already hated that all the small retailers I use have migrated to it and it pushes you to set up an account so that it can connect all my purchasing habits together from what should be independent retailers.
Thanks for sharing. I would definitely be interested in a write-up on how you solved the DNS+certificate problem please, as this is a problem I’ve run into on my self-hosting journey.
I have no experience with UPSes, but I have used LFP batteries a fair bit.
The main compatibility issue will be the battery voltage and charging system. Most Li-based batteries have slightly higher nominal and charging voltages than lead acid types depending on the cell configuration.
Check the specs on your UPS model to be sure it is compatible and if it is, I’d go with LiFePO4 (LFP) batteries rather than other Lithium chemistries at this time. They don’t weigh as much as the equivalent lead-acid batteries, are roughly the same size for the same capacity and handle deep discharge better than lead-acids. Plus LFP batteries aren’t as volatile as some other Lithium batteries.
I would tend to agree with the other comments - media center device hooked up to the TV if you can’t fix the internal display.