After the annual service, a screwdrive will probably work quite well. However, a year later, when the threads have picked up some road dust and the grease has hardened, they won't cope.
I've tried several drills over the years - mainly with Ni-cad batteries. these suffer from the ' memory effect' and you really need to discharge fully before recharging, Can be done by using electical tape to hold the trigger down with the drill out of use, but a bit of a fiddle. If you have two batteries then you may not get caught out but the problem is only postponed. The larger drills say 18v. and above do the job but are heavy (particularly since leg duty is allocated to HID) and there is some danger of overwinding the leg and thus distorting the body of the caravan.
I've now bitten the bullet and bought a Bosch 14v with two Li-ion batteries which do not suffer from memory effect. It is light but strong and very useful round the house as well. Better still HID loves it !