Hey Jim,
If you can get a Uniross fast charger from Currys, and with it comes 4 Nimh AA's. If your phone needs 4 then id get 8, and while 1 set of 4 are charged and left in the charger, the other 4 can be in the phone. I would just put some tape over the terminals so the phone dock doesn't charge it.
The best NIMH AA's I have used are the Green Energisers. They may not be the highest MAH but they seem to last the longest I have tried. The other alternative is the new Blue Energisers which are Lipo AA's.
It would charge them, but there is a likelyhood of them being overcharged - I am not sure... but if ever I am not sure I would do the option which is less risky.
Chris