Improving the MD-(UV)380/RT3(S)/GD-77 Charger

The battery chargers of many chinese HT's are known to be unreliable, noisy and to overcharge the battery.

The TYT MD-380, TYT MD-UV380, Retevis RT3, Retevis RT3S and the Radioddity GD-77 share the same charger cradle with similar electronics inside. The following picture shows the PCBs found in the MD-380 (left) and the GD-77 charger (right):

I've read about a very easy and affordable modification for these chargers here: The goal is to exchange the charger's guts with a small TP5100 board:

After I ordered and received 5 of these PCBs for 6€, I performed the following steps of the modification:

That's it. The final result will be a much more reliable charger that still shows its state via a red (charging) and a blue LED (charging done).