Given how decent the mic preamps in the D-10 are said to be, and if so, all you need is 9-10v DC (@ possibly insignificant mA?) I wonder if an internal hack for boosting DC to the mic jack would be possible. Trouble is, the components in these things are getting so tiny they'll eventually be impossible for a normal person to work on (if they're not already). But I'm thinking, if not able to be inside the recorder, a teeny flat cellphone-type rechargeable, low-profile Li-ion cell virtually sculpted to the D-10 case, with a charging jack, and hard-wired back into the recorder's mic jack.. just a thought.
Dave