regulated 2S 18650 battery pack for DJI goggles

thingiverse

Using the flat 4S pack uploaded previously for my DJI goggles has been overkill. It's heavy, and even after flying all my quadcopters in a long session, the goggle battery is hardly used. A 2S pack is more appropriately sized, but the 2S battery voltage triggers an annoying low voltage warning on the goggle OSD. Since I'm not concerned about draining the pack, I incorporated a MT3608 voltage regulator board into the pack. The shorter XT60 connector connects directly to the cells and is used for charging the pack (with the balance plug). The longer XT60 lead is a regulated voltage and drives the goggles. The voltage regulator is adjustable, but I removed the adjustment pot and replaced it with a fixed resistor to give about an 8.5VDC constant voltage. Keeping the regulated voltage setpoint low (rather than 12 volts, say) makes the regulator more efficient. Battery contact are the same Keystone 209 leaf spring contacts used in my previous packs.