> I'm wondering if there's such a thing as a phone battery charger -- the kind you insert the battery into, rather than plugging in the phone.
Yep, I got one with moveable pins so (in theory) you line them up and it charges any battery that the adjustable grip can hold.
I have no idea whether it works - have tried it with two batteries but in both instances I don't know whether the charger is crap, the battery buggered, or the phone fucked.