I use a 3S 3000mah I think its 8C lipo in my 3PK and anothe rjust like it in my 3PJS. There is no 'parasitic' drain like when a lipo is connected to an ESC.

I don't take mine out or disconnect them between uses. The only time I remove them is to charge them. Done it this way for over 2 1/2 yrs without any lipo probs. I monitor voltage off the radios display and charge when I get to the point I don't want to worry about it anymore, usually when it drops below 10v.