Here are the results of my battery life tests on the DR100:
NiMH AA (eneloop): Phantom off - 4 Hrs, 20 minutes
NiMH AA (eneloop): Phantom on drawing 10 mA - 31 min. 14 sec
Lithium: Phantom off – 6 hrs, 3 minutes
Lithium: Phantom on drawing 10 mA – 2 Hrs. 48 minutes
The chargers I use to recharge the lithium battery came with my Pocket PCs (have 7 of them: 2 Casio, 2 Toshiba, and 3 Dell). They range from 5.4 to 5.7 volts, current rating ranges from 1A - 2.5A