Several years ago, I worked in a shop that used Black & Decker electric screwdrivers with Versapak batteries. They had a green plastic body and a silver painted metal gearbox and an orange switch that you could flick with a thumb to change direction, and press to engage, whether you were holding the body thumb up or thumb down. We experimented a bit to get the right setting for the adjustable clutch. I never even checked if it was calibrated in any particular units, but they were consistent from one unit to another and didn't change with time, and didn't break.
The only problem I recall was a girl who was new to the operation somehow got the idea to give the screws an extra twist with the power 'off' after the torque limiter ratcheted. Those particular screwdrivers were consumer products, and didn't limit the torque with the power off, so she screwed up quite a few assemblies before I caught her and retrained her.
I just looked at the one I have here. It is a model VP730, Type 2, 3.6VDC, 180 RPM. The body is straight and does not fold into a pistol grip, unlike some newer models I have seen and bought.
At that time, Versapak meant NiCd cells, which thrive on abuse, and gave us no particular trouble in a production environment. The newer Versapak Gold batteries with NiMH cells are better in a home environment where self-discharge is a nuisance.
Both types of Versapack batteries are still available online, but I have no idea if they're still in production because Versapak has sort of gone out of style. I also don't know if that particular driver is still in production. Anyone who is still using them probably won't part with any.
Atlas Copco, Bosch, Aimco and Stanley are considered the best for heavy volume industrial manufacturing. A new tool, properly selected, from any of them should provide excellent performance.
Here is probably the dean of the production screwdrivers from Aimco. They are almost indestructible but a little pricey. They are available from numerous distributors with a nominal discount.
They have all types, here is the direct plug in type that I'm familiar with.
