The POTA Power Pack: Built-In 16Ah Battery in a Tactical Backpack
- 4 min reading time
Build | DIY | Field Power | W4GGJ
I've been hauling a separate DIY battery box to every activation. It works, but it's one more thing to pack, one more thing to strap down, and one more thing that doesn't fit cleanly in the bag. So I fixed it.
This is the build where the battery becomes the bag.
The Concept
Two LiFePO4 8Ah batteries wired in parallel for 16Ah total capacity — living inside the bag itself. No external box. No extra carry. The whole power system is self-contained in a 50L tactical pack with the output panel 3D-printed and MOLLE-clipped directly to the side.
Flip the master switch, check the voltage, plug in the radio. That's it.
The Bag
I picked up a 50L Waterproof Military Tactical Backpack for this build. It's got enough room to swallow the batteries, the DigiPi, the Xiegu X6200, cables, and still have space for the rest of the go-bag essentials. The MOLLE webbing on the outside is what made the panel mount possible — the 3D-printed box has four MOLLE clips on the back that lock right into the side of the pack.
Waterproof construction is a bonus in Florida. If you've ever activated at a coastal park when a squall rolls in, you know exactly why that matters.
The Panel
The output panel is a 4-in-1 ON/Off Charger Socket Panel that packs a lot into a tight space:
- Illuminated master rocker switch
- Dual USB QC 3.0 ports
- USB-C PD fast charge port with built-in voltmeter
- Cigarette lighter socket
- Dual Anderson Powerpole connectors
The voltmeter is what really sells it. At a glance I can see battery state — no separate meter, no digging through the bag. When I flipped the switch for the first time and saw 13.1V glowing back at me I knew the build was solid.
The Box
I designed the 3D-printed enclosure specifically around the footprint of that panel. Four MOLLE attachment clips on the back, panel mounted flush to the front face. The blue PETG matches nothing and I love it. Wiring runs from the panel down into the bag to the battery terminals — clean enough that it doesn't snag when you're zipping pockets.
The panel sits in the side pocket area with the wires routed down and out of the way. The batteries sit in the main compartment with spade connectors on the positive terminals and a fused line to the panel. Parallel wiring means I'm drawing from both cells simultaneously — 16Ah at 12.8V nominal.
Why This Changes Everything
My old setup was a separate ammo can battery box with external Anderson Powerpole output. I had to carry that in addition to the backpack. Now it's one bag. Grab and go. The radio, the DigiPi, the power — it's all one unit.
For POTA activations, that simplicity pays off. Less time setting up is more time on the air.
What's Running Off It
At a typical FT8 activation, the Xiegu X6200 pulls maybe 1–2A on receive and 5–6A on transmit at 10W. The DigiPi (Raspberry Pi 4) pulls around 1–2A. Call it an average of 3–4A combined during an active session. At 16Ah, that's 4+ hours of continuous runtime without sweating it.
I've never drained a battery on an activation. Now I have even less reason to.
Would I Build This Again?
Already thinking about version 2. Maybe a slightly larger panel cutout for better airflow, and I want to add a low-voltage cutoff relay at some point to protect the cells from over-discharge. But as a first build? This thing works exactly as designed.
73 de W4GGJ