r/HomeServer • u/Hot-Adeptness7155 • 12h ago
I’m designing an internal UPS that fits in a PC expansion slot and drive bays. Would you use it in your home server?
Along with an electrical engineer friend, I am in the early stages of working on an idea for a project I wish existed, but doesn’t (to the best of my knowledge).
Sometimes power outages happen, especially short ones. In order to survive these blips, most people would install a UPS between the wall and the power supply. Unfortunately, most uninterruptible power supplies are bulky, use lead-acid batteries that don’t last very long, and beep once they die.
I have designed a PC expansion card that sits between the existing power supply and the motherboard, GPU, and hard drives, etc. Up to two modular LiFePO4 batteries that fit into unused 3.5” HDD slots can be plugged into the expansion card. The batteries can last around 10 years and the packs can be replaced at the end of their life.
Essentially, it can turn any mid-tower PC into a sort of laptop with a battery big enough to allow a graceful shutdown or hibernation via a usb jumper to the motherboard.
Improvements over existing UPS’s:
- Small and lightweight to ship - no need for additional AC->DC->AC Circuitry
- Completely internal
- Long battery life
- Modular and replaceable battery packs
- No beeping
- Graceful shutdown or hibernation on mains power-loss
- Will auto-restart your PC when mains power is restored
What I am not claiming:
- That you can continue hardcore gaming or intense rendering
- Surge protection
- Backup power for external devices
I am thinking about the casual home server builder who wants to recycle an existing gaming PC chassis into a dedicated server with TrueNAS or Proxmox, not the power user who has a rack mount in their extra closet. Something neatly internal with a high WAF (wife acceptance factor).
I wrote this post to gauge interest in the idea, and to see what features you would like to see in v1. My next step will be to build and test a physical prototype.
Possible extra add on features, depending on interest:
•2.5” SSD-Sized battery pack for smaller form factor PC’s
•Built-in KVM over IP controller with HDMI jumper to GPU or motherboard
•Built-in extra SATA ports
So 3 Questions:
- Does it interest you?
- Is it something you would pay for?
- What haven’t I thought of yet?

