DIY LiFePO4 Power Station

A 50 Ah LiFePO4 battery in a Powerwerx MEGAbox, with a 400-watt inverter and solar charging. I built it in 2020 and upgraded it in 2026 to power a Starlink Mini.

Orange Powerwerx MEGAbox with a carry handle, a row of USB and 12-volt outlets and a voltmeter reading 13.9 volts on the lid, and a silver inverter mounted on the side — The power station today, after the 2026 upgrade: a 100 W USB-C port, the voltmeter port, a 12 V outlet and the Powerpole cover on the lid, with the 400 W inverter on the side

I wanted one of those 12-volt power stations for a long time: something to charge USB devices from, plug 12-volt gear into, and even run a few small 120-volt devices. Instead of buying one, I built my own around a Renogy 50 Ah LiFePO4 battery and a Powerwerx MEGAbox, an orange power box that already has the outlets, fusing and a work light built into the lid. A pure sine wave inverter on the side adds 120-volt power, and a folding solar panel keeps it charged in the field.

Six years later it's still in use. In 2026 I upgraded its USB-C port so it can power a Starlink Mini satellite internet dish with a single USB-C cable.

50 Ah12 V LiFePO4 (about 640 Wh)

400 Wpure sine wave inverter

100 WUSB-C PD, up to 20 V

110 Wfolding solar panel

40 Afused DC outputs

2020

The original build

I made a video of the whole build on my YouTube channel, Random Gene, from unpacking the parts to a real-world test with everything plugged in.

I went with the MEGAbox because, for the price, it was cheaper than buying and wiring all the outlets myself. The Powerpole outputs and the binding posts connect straight to the battery through a 40-amp fuse, and the USB ports and 12-volt socket run through a lighted 15-amp circuit-breaker switch. A built-in LED work light has several steady and flashing modes.

Making the battery fit. The MEGAbox was designed for a different brand of battery. The Renogy was too tall, so the lid wouldn't close over the connectors. A spacer under the lid's panel raised it enough to clear.
Mounting the inverter. The Wagan Elite 400W Pro pure sine wave inverter is screwed to the side of the box. Its fused battery cable runs into the box through a grommet. With a 50 Ah battery I keep the load to about 300 watts.
Two battery leads. One pre-made cable feeds the inverter and the other feeds the MEGAbox's outlets, which already have their own fuse. Foam spacers keep the battery from shifting, and there's still room in the box to store the charger.
Charging. A CTEK Lithium US smart charger (4.3 amps, with an 8-step LiFePO4 charging program) tops the battery up from 120 volts. I put Powerpoles on its leads so it plugs into one of the Powerpole outputs, with no need to open the box.
Solar. A Renogy Rover Elite 20-amp MPPT charge controller and a Powerwerx 110-watt folding panel also charge the battery through a Powerpole. I replaced the panel's MC4 connectors with Powerpoles to keep everything on one connector, and made the old MC4 plugs into an adapter. The controller and cables live in a separate small ammo box, so I can use them with other gear too.

The orange MEGAbox on a workbench, with the outlet panel, switch and Powerpole cover on the lid — The MEGAbox as it came, with its outlets already in the lid

Hands holding a black plate with three round holes over the open box, with the Renogy battery inside — The spacer, cut to raise the outlet panel so the lid clears the battery

The MEGAbox closed on the workbench, with the raised outlet panel on the lid — Spacer installed: the lid closes over the battery

The silver Wagan inverter screwed to the side of the orange box — The Wagan inverter mounted on the side of the box

Close-up of the Wagan Elite 400W Pro inverter on the box, with its cable entering the box through a grommet — Its battery cable goes into the box through a grommet

A hand on the lid of the power box, with the blue voltmeter lit up — First power-up: the voltmeter reads the battery

The open box showing the battery, wiring, foam spacers and the charger stored inside — Inside: the battery, the two battery leads and foam spacers, with room to store the charger

The Powerwerx FSP-110W folding solar panel, folded, on the workbench — The Powerwerx 110-watt folding solar panel, folded

The folding solar panel opened out to its four panels on the workbench — Opened up: four panels

The four-panel solar panel propped up outdoors in the sun — Out in the sun

Renogy Rover Elite charge controller with its screen reading 13.7 volts, in front of the power box — The Renogy Rover Elite MPPT controller reading the battery at 13.7 V

The charge controller on the workbench with Powerpole leads and a red extension cable, next to its manual and the power box — Wired with Powerpole leads, so the controller and cables can go in their own ammo box

For the real-world test, it ran all of this at once while the solar panel charged the battery: a 12-volt ICECO refrigerator holding 35°F, a 2-meter mobile radio and a handheld radio, a cordless drill battery charger and a drone controller on the inverter, and my phone on USB.

The power station on a garage workbench with radios, phones and chargers plugged into it — Everything plugged in at once while the solar panel charges it

A tan ICECO 12-volt refrigerator running from the power station — The ICECO 12-volt refrigerator running from the 12-volt outlet

The ICECO refrigerator's display reading 35 — Holding at 35°F

2026

The upgrade: powering a Starlink Mini

White Starlink Mini dish propped on a patio lounge chair, cabled to the orange power station on the ground — The power station powering the Starlink Mini

A USB tester plugged into the old USB-C port on the power box, its screen listing the fast-charge modes the port supports — Testing the old USB-C port: it tops out at 12 volts and 1.5 amps (18 watts)

The Starlink Mini runs on anything from 12 to 48 volts and uses 20 to 40 watts, sometimes up to 60 watts when it starts up. None of the power station's USB ports could supply that. The original USB-C port only goes up to 12 volts at 1.5 amps, which I confirmed with a USB tester and from its specifications.

The 12-volt socket and the Powerpoles could run it, but at 12 volts the Starlink draws at least 5 amps, so any long cable run would need heavy 14-gauge wire. A USB-C port that supplies 20 volts moves the same power at a much lower current, over a regular USB-C cable.

A new 100-watt port. I replaced the old USB-C port with a 12-volt panel-mount outlet that has a 100-watt USB-C Power Delivery port (up to 20 volts at 5 amps) and an 18-watt Quick Charge 3.0 USB-A port.
Bench testing first. On the bench, the USB tester asked it for 20 volts and a load bank drew about 32 watts, the Starlink's normal range. It held 20 volts, and after running for a while it was only 84.5°F.
Installing it. I removed the old port and crimped and soldered spade connectors onto the new one's leads.
Keeping the voltmeter. I liked being able to read the battery voltage on the old USB-C port, so I moved it into the spot where the dual USB port was.

The new round USB outlet wired to a bench battery with alligator clips, a USB tester and load bank plugged into it on a cutting mat — Bench test of the new outlet from a spare battery

The USB tester requests 20 V: 20.1 V at 1.63 A, about 33 W

Electronic load bank with a cooling fan, its screen reading 20.0 volts and 1.59 amps — The load bank drawing 1.59 A at 20.0 V

Infrared thermometer reading 84.5 degrees, aimed at the new USB outlet — Heat check after running for a while: 84.5°F

The power box lid with two empty round holes in the outlet panel where the old USB ports were removed — The old USB ports removed

Underside of the open lid, showing the backs of the outlets with red and black wires on spade connectors — Wiring under the lid, with the new spade connectors

The new 100-watt USB outlet installed in the first slot, next to the dual USB port, with the old voltmeter port lying loose on the lid — The new port in the first slot. The old voltmeter port (loose, above) is about to replace the dual USB port.

USB tester and load bank plugged into the new port on the finished power box, with the voltmeter reading 13.6 volts — Final test on the finished box. The voltmeter shows the battery at 13.6 V.

Parts

Powerwerx MEGAbox portable power box (since replaced by the MEGAbox2)
Renogy 12 V 50 Ah LiFePO4 battery
Wagan Elite 400W Pro (EL2610) pure sine wave inverter, mounted on the side of the box
CTEK Lithium US (56-926) LiFePO4 charger, 4.3 amps, with Powerpole leads
Renogy Rover Elite 20 A MPPT solar charge controller
Powerwerx 110-watt folding solar panel, with Powerpole connectors
2026 upgrade: 12 V panel-mount USB outlet with 100 W USB-C PD and 18 W QC3.0 USB-A

Links

The build video on YouTube Random Gene on YouTube Powerwerx MEGAbox2