I used a 14.4 volt Bosch for quite a while, and this has the advantage of torque settings so you don't strain the steadies/chassis. Howver, most of these drills still use Ni-Cad batteries which do deteriorate with time to the point where they will not hold a charge. This means that at some point you will find yourself having to take the charger with you as well, as the battery may be flat by the time you leave. Replacement Ni-cads are not really economic, relative to the price of a new drill. The new Li-ion batteries wil be much better, but are currently expensive. I've now gone back the old hand winder, being 100% reliable.