QMX Battery Backpack and Rails

This is a 3S battery pack for the QRP Labs QMX Transceiver. It holds 3x Li-ion packs I purchased from Amazon.  It also includes rails to protect the front panel knobs.  If I don't count the rails, the battery pack only adds 8mm to the thickness of the QMX.  It prints flat and is designed with "hinges" that fold up.  Then screw the sides to the QMX.  The OEM QMX aluminum side covers are left in place on the QMX and the original screws are sufficiently long to hold it together.   

The three batteries each came with a JST connector that I cut off.  I soldered the batteries together in series.  They peak out at 12.1 VDC and settle in 11.1 VDC at their nominal voltage.  Which is a nice comfortable voltage for the QMX for SSB, Digital, and CW.  I had my first QSO with my newly finished QMX kit and the battery pack yesterday at US-1974!

EDIT: I added a version with no rails and I added the enclosure for the USB-C charger.  The USB-C charger requires either three M2.5x8mm or three M2.5x10mm counter sunk screws.  Either length will work.  I bought the linked set below, and ended up using the 8mm to hold the sides of the backpack to the QMX.  The 6mm that are included with the QMX will grab extruded enclosure.  A few extra mm gave me peace of mind.

batteries: https://amzn.to/4m9zwe1

pigtail connector: https://amzn.to/4bULzbT

charger: https://amzn.to/3POhm5  make sure to get the 3s!

charger plug: https://amzn.to/4sSaBy6

M2.5 counter sunk screws: https://amzn.to/41Rm05v

I might be able to squeeze the charger into the backpack if I used smaller batteries.  Personally I'd rather have an external charger and longer run time in the field. Drop a comment if you think it's better to be internal with a smaller battery.