XT-60 Empty / Full / Storage Indicator Cap

thingiverse

After an exhaustive search for an XT-60 battery cap/plug, I couldn't find one that met my expectations. What I wanted was a product that would clearly indicate if the battery was fully charged or empty, as well as its storage charge level. For those who are unaware of this crucial information, it's essential to avoid leaving Li-Po batteries at either full or empty levels for extended periods, as this can cause them to swell and die prematurely. To mitigate this risk, you should discharge a full battery down to the 'storage level' of 3.8V per cell (or charge an empty one up to that point). To use this product effectively, simply place the safety cap on with the F facing outward to indicate a fully charged battery. If it's at storage charge, add one of the "S" endcaps to the F to clearly signal that status. If you've flown and depleted the battery below 3.8V, turn the plug around so the E is facing out and attach the S plug. Note that the S plug is entirely optional.