I recently bought a cordless ph> "To reduce the risk of fire, use only 3.6V 850mAh Nickel Cadmium
> (Ni-Cad) cordless telephone replacement battery pack."
> I've heard about the dreaded "memory effect" with NiCd batteries, so
> I'm interested in replacing it with a NiMH one. Someone who is
> selling a 3.6V 1000mAH NiMH battery on Ebay claims it works with my
> phone, but will it really be safe? Wouldn't want to install a NiMH
> battery and have the house burn down.
The NiMH battery will power the phone just fine, once it's charged. But you need to have a charger designed for NiMH batteries. Some Ni-Cad chargers also are designed to charge NiMH batteries, but some are not. (I assume there is a difference in charging current or something.) Don't use NiMH batteries in a charger designed only for Ni-Cads. Since you will undoubtedly be charging the batteries in the phone, not swapping them out into a charger, you shouldn't use NiMH batteries in a phone that says to only use Ni-Cads.
The only exception I would make to this is if the phone vendor sells a NiMH replacement battery specifically intended to be used in the phone in question. And I would go with the vendor's battery, in that case.
Michael D. Sullivan Bethesda, MD (USA) (Replace "example.invalid" with "com" in my address.)