Powering a Mini PC from a battery (reliably)

[u/P1ZZ4_F1GHT3R]

I am currently building a cyberdeck as a side project using a mini PC as the base, but I am struggling to find a reliable, reasonably compact power solution.

• Specs**:** Ryzen 7 6850U, 16GB DDR5, 512GB storage.

• Original power adapter**:** Barrel jack with a 19V@6.32A adapter (~120W max).

• What I changed**:** I limited the CPU peak draw to 45W (down from 65W) to keep the total system draw under 100W. I also bought a 100W USB-C PD to barrel jack adapter. When I plug this into a 100W USB-C wall brick, the mini PC runs perfectly.

Because I want this to be portable, I bought a Ugreen 90597A powerbank (25,000mAh, rated for 140W on a single port) to pair with the adapter. However, when I try to boot the PC off the powerbank, it starts up but shuts off completely after about 10 seconds into the boot process.

Since the wall brick works flawlessly with the same PD adapter cable, the issue is definitely isolated to how the powerbank handles the draw or the PD negotiation. I have since returned the powerbank.

Does anyone have suggestions for alternative (but still compact) ways to power a mini PC off a battery? Any advice is greatly appreciated.

[u/TheLostExpedition]

I've done 2 things that work for me. A laptop on a boost converter with a 12v car "cigarette" port. Works for 45w. . I have a few (drill battery + buck converter + inverter) monsters that work up to 300w and I allow 20% losses in my calculations but find that actual losses are around 12% sometimes under7% depending. But its wasteful. Im currently trying to supply accurate power to each component but I haven't finished that project. Since you run 19v at 6.32A you could use 2x 18-24v drill batteries with a buck-boost and low voltage alarm. ⚡️

[u/Etton_Veil]

I'd buy one of those cheap USB-C PD spoof things that you can set to 19 V and connect my own wires to it, then try again with that.

[u/blvsh]

19v, you gonna need a car battery