I finished the drill.
Although I did not cut the handle, and I realized thet it is unnecessary to put in peli or other waterproof stuff.
Now the batteries are in my older equipment bag.
The capacity:
We used it for drilling 14mm diameter and 10 cm deep holes for wedges.
The stone was grey limestone the drilling direction was perpendicular to the structure.
It could drill around 1,8-2,0 m, when I started to feel the weakness of the batteries.
All things considered it is a good choice for secondary drill.
I put 5meters of silicon cable on it.
I'll take some pics to show what have I made.

Hungarian caver, member of the Hungarian cave rescue Service, certified blaster, and explosive pyrotechnics test engineer.