Okay, got the scoop from weasel:

"As for the charger with programming, it really depends. If you are just doing an "encoding" using the dis V44 then you are ok without it. If you are doing an actual programming with either dis V44 or any SSS version then it actually won't let you program unless the voltage is measured over 13 volts at the connector."

So, it seems I'm okay with the the small stuff. If I ever NEED to do some serious programming (which I hope not) then I probably would take it to the dealer.

I'm still going to investigate getting some kind of battery charger though.