Build notes on a light-weight portable 12v 50Ah LiFePO4 battery in a pelican laptop case for HAM radio and other uses – great for POTA and SOTA trips. Features include an AMP meter/gauge, main battery disconnect, dual Anderson Power Pole ports, PD/USB-C and USB QC 3.0 charge ports all housed in a lightweight easy to carry laptop case.

The battery pack that was chosen was from the LiFePO4 flat pack from A123 Systems. Battery specifications were 50Ah, with a 50A output on the XT90 connectors, charge voltage of 14.6VDC and all of this in a compact size 2.5″ x 9.5″ x 12.25″ size.

On the web site there were plans for a custom BMS (battery management system) PCB board and a parts list. Using those plans and parts a custom PCB was ordered from PCBWay and assembled:

The battery as shipped from came with two XT90 connectors on the terminal board, these were de-soldered and removed which allowed shorter stand-off mounting posts to be used for mounting the custom BMS board to the pack. After digging around on Amazon some U shaped stainless steel brackets were found (18mm X 22mm) and holes were drilled in them and using the bolts and nuts from the battery they made great mounting brackets for the battery pack.

Some measurements were made to include the additional components and ports and the pack was positioned inside the pelican iM2370 case and holes were drilled in the bottom and button head bolts were used to secure the pack in the case – best to measure 3 or 4 times and cut/drill 1 time! Special care was taken to make sure everything would fit and there would be room to secure the pack to the case:

I decided to use a 35mm DIN rail and terminal blocks to mount cross connects to connect everything together – I had originally planned on mounting the shunt for the AMP meter on the DIN rail as well but later decided to mount that to the top front side of the case after having a custom 3D-printed mount made for it (Thanks to KF5ZBL for printing):

Final paper templates were made and printed then taped on the outside of the case and center marks were made with an awl. The larger holes for the main 100AMP on/off switch, charge port, dual Anderson Power Poles, and USB combo ports and meter were drilled out:

Custom 12AWG silicon covered cables were measured and fabricated for all the connections. Silicon sheathed wire is really easy to work with and very flexible, it also will not melt/burn very easy:

Final assembly – All that was left was to wire up all the ports and connectors and test everything.:

The first real field use was Winter Field Day 2023 – This pack is easy to move around and carry out to the park and using a Power Pole jumper cable was super easy and fast to power up a go-box. The pack was used for just over 6hrs of continuous use with a Yaesu 991 radio running SSB non-stop at 100W – at the end of the day over 73% of the pack was left – the fuel-gauge AMP meter was a nice addition to keep track of use and battery level.

More build photos and photo notes and build links in in this Flickr Gallery and here is the main wiring diagram I used: