Einhell Parallel Battery Adapter (FPV field pack)

I made this design based on the einhell battery adapter from datdiy. It connects two 18V drill batteries in parallel to form a big capacity battery pack. The USB Socket allows you to recharge your Phone or Laptop. The barrel jack connectors are for other DC devices. I use it for a Lipo Charger to recharge Drone batteries. I also use it for camping purposes.

Building instructions:

You need to add threaded inserts to the adapters and the top box and then you can screw it all together. The top box needs eight inserts on the top and bottom four holes. The adapters need five inserts each. You have to use different holes on the left and right one! Tipp: Use the bottom box as a template for the inserts. 
The wiring is pretty easy just connect everything in parallel. You don't need any diodes like some other project suggest because the pack already has one internally. (At least that's what i was able to observe by voltage drift between the packs)

Print instructions:

PLA or PETG or ASA or what ever you prefer!
20% supports
4 Perimeters

All Parts except the adapter can be printed without supports.
The adapter needs supports “everywhere” check the screenshot!

For a good looking finish print in two colors ;)
Color1: Adapter + bottom box lid + top box lid
Color2: bottom box + top box

Bill of Material:

• 14x M3 Threaded Inserts
• 4x M3x8mm Flat Head
• 4x M3x15mm Flat Head
• 4x M3x8mm Button Head
• 6x M3x6mm Button Head (Can be 8mm too)
• 4x crimp male spade connectors
• 1x USB Car Socket
• 2x Barrel Jack Connector

PS: Feel free to remix for other power tools manufactures!

Disclaimer:
I don't take any responsibility for anything I showed here! If you burn down your house/car/etc. or injure yourself and/or others it is on you! Make sure you know what you are doing!