I went through the
www.team-orion.com and found something on NiMh batteries:
How to treat your 3000 Ni-Mh cells
We've updated the Battery FAQ after having received notice from customers about fast degrading performance on Panasonic 3000 Ni-Mh cells. Now I know that the manufacturer recommends to store them in a charged state, but usage tells a different story.
If you store your packs in a charged state (even partially), performance will degrade very quickly and you will notice a lack of run-time and punch. If you discharge the same packs like you would discharge Ni-Cd cells, race, dump the packs and then put them on an equalizing tray, the performance will be maintained at the original level.
What do you guys think?