I've bought a couple of the Ryobi 12V drills with the Ni-Cad batteries. I must have 4 batteries, all dead. Converted one by removing the batteries and adding a cord with a cigarette lighter plug for the boat - works fine on boat power! Two more packs I've converted to the Ni-Mh batteries, using the original Ni-Cad chargers - both working fine. Oh yeah, no problems with the drills themselves - just the d..n batteries!