I'm using an Eskimo gear reduction setup on a homemade brace connected to an 8" Strikemaster Lazer hand auger section, (no manual handle section) powered by an 18V Ridgid brushless hammerdrill. In early season last year, I got around 55-60 holes in ice on a 4.0 AH battery over a 3 week period, (I went 3 weeks without recharging, just to see how long it would last). Ice ranged from 6-9 inches over that period.
Here's my setup. I plan to add a 6.0 battery or 2 to my setup this year.