Are the rechargable batteries in the Eton/Grundig radios replaceable AA's that can be swapped easily or is it a different type battery?

I looked at the Eton/Grundig radios and then bought a Sony AM-FM TV Weather Radio instead. I can use standard NiMH rechargables (I already have a solar battery charger which will do four NiMH AA's) and not be hassled with cranking.

From what I can determine, the NOAA Weather channels are useless unless you are in their relatively small footprint. They use LOS ~162 MHz at 90-100 Watts, really just designed for guys out on their boats who need to know about storm fronts. However, it receives AM well, FM in mono format and the TV audio is very clear. I figure if a big earthquake hits it will be a race to see who can get their back-up power first and between AM, FM and TV audio, I should be well covered for local News.