Michael-

I guess I will take the contrarian view. I have a field box with power panel and a rechargeable glow driver. I never use the rechargeable one. The main reason is it is kind of a pain to make sure that it is fully charged. With the power panel, I can always tell by looking at the meter to make sure I am getting adequate power to the glow plug and I can adjust the juice as necessary. I have a basic Tower Hobbies power panel, which is about as good a deal as anyone else has.

As someone else is mentioned, you charge the field box battery through the jacks for the 12V starter. I have a couple spare banana plugs that I stick in and then I clip my 12V charger to the plugs.

-Scott

P.S. This advice is from one lawyer to another, so take it with a grain of salt.