bobby49 wrote:Wow. Those hammer drills don't come cheap, do they?
No, they don't. My Bosch cost $150 just for the drill, without any batteries. (looks they they have gone up quite a bit since then) The lithium batteries are very pricey, but a much better bang for your buck than the old NiCad ones. I paid $149 for a kit with two batteries and a charger; one battery was the 4.0 amp/hour, the other was a 2.0 Amp/hour.
As far as how many holes, that varies a lot with the size and the depth of the hole, as well as the rock type, etc. When drilling 1/2" holes in limestone, I can usually drill 8 to 10 holes to a depth of ~10". Keep in mind that I usually use my drill for micro-shaving, and not for setting bolts. Anchor bolts would usually only require a 3/8" hole, and you'd probably drill it ~3" deep. So you could expect a lot more life out of your battery. Still, it is always a good idea to have an extra battery on hand.
By the way, the 2.0 Amp/hour battery didn't seem to have a proportional amount of battery life to the 4.0, not sure why. At least that was my experience with the Bosch brand batteries.
Trogman