Multitude of reasons to stay away from NiMh batteries, one of which is that they typically lose some charge overnight unless you leave them on a charger until very moment you would use them. Their real capacity also rarely reaches the advertised capacity. I've been using these type of batteries in other RC and photo applications for years, and LiPo alternatives are always far more desirable in all mentioned respects.
I guess my question about generic Lipos would make more sense if related to a generic locomotive (home-built) that might not be able to accommodate the new PF battery box or the PF rechargeable battery pack.
I have quite a few PF bits and pieces on order, so I plan on experimenting and hopefully have something to report back soon.
Thanks for your reply!
ig