GD-77 18650 battery pack

thingiverse

PLEASE NOTE: I do not present this as a full function replacement for the OEM factory battery pack. Any use is at your own risk. This design was simply a method to house two 18650 batteries, with no consideration given to addition of battery protection circuitry. Having said that, I revisited my build and later incorporated a BMS board - specifically this one from Amazon: https://www.amazon.com/gp/product/B0842Q1F68. The BMS board fits tightly inside the pack on top of the batteries, requiring proper routing of connections. I used AWG 20 silicon wire for the BMS connections. Zvones52o did the heavy lifting with his battery eliminator back piece for the GD-77, and I made some modifications in Tinkercad to accommodate addition of two 18650 batteries. My version uses threaded inserts for screwing parts together, with holes roughly sized for using inserts for 3mm flat head beveled screws. Electrical contact points for charger and radio are made from nickel-plated strips intended for spot welding batteries into packs, with a dollop of solder creating a raised area for the contact. You may want to explore alternative approaches. The Tinkercad workspace can be found here: https://www.tinkercad.com/things/gwjK4Wsbj8v