During the last year I have replaced all my Rx and Ignition NIMH batteries with lithium ion or Lipo4. The advantage of both compared with Lipo is they can be safely kept and charged in the model, but with limited access on my scale type models connecting both a power and balance socket for charging is awkward. I retained the existing and adequate JR connectors but they also require safety connector locks.
The first pic shows the old and new system.
My solution is to rewire all battery backs and related Rx & Ignition power plugs with these AMASS 3 way connectors for Pos, Neg and centre balance wire so that only single connector is required for charging or flight. I'll also make special charger adapter leads to connect the balance ports at the charger.
These connectors have 2 mm sprung pins rated at 15amps and have sufficient friction to negate the need for connector locks but have nice grab detents to allow separating.