So I got chance to try out my 6" nils convertible auger I bought last year with the dewalt 991 today. I kinda wanted to get 5amp batteries since that's what most seem to suggest but I was able to get my hands on a 2 pack of dewalt 4 amp batteries on sale for a lot less than the 5's. The battery indicator only shows 3 bars for 'full' on the four amp batteries where as I believe there's four indicator bars on the 5 amp (not sure).
Anyways, I had 8 to 8.5" inches in just about every hole I drilled. Arrived in the morning to fish and it was 15 degrees outside to start and ended up at 28* for a high. We were out for about 7 hrs and had the drill and battery laying on the ice all day. At the end of the day my uncle and I drilled easily 60+ holes on the ice and the battery indicator still showed 2 out of 3 bars lit up. So I'm not sure how many I would get before I had to switch to the 2nd battery but for my normal needs this is more than enough juice to take out for a day of fishing.
Will say this set up is awesome, I own an Eskimo 8" propane auger and a strikemaster 8" which are both great augers but I see them collected dust in the future. This set up really cuts like a hot knife thru butter. 8 inches in about four seconds.
