An older Energizer 4-bay charger (forgot the model number) will charge 1-4
AA or AAA cells (NiCD, NiMH, or RA) at a slow rate. I think they are discontinued
which explains why I was getting them for $5-10 each. Not super fast but well
worth it if you can find them. Since each cell is independently charged (with its
own LED) you can mix cell types/sizes without a worry, if necessary.