I know how the headmasters work,by flooding condensor on the low ambiant. But say say you find a leak on one, how do you go about charging it after your leak has been repaired? Do you need to pull the rest of charge and weigh in acording to nameplate or can you top up? If you can top up how does that work in summer when your using less of the charge? Just a general question from a greenie, thanks for all responses.