Ok thanks. Will rapid charging hurt my batteries?
It will if it heats them up too much.
The chargers that announce "charge your batteries in an hour!" = "fry your batteries in an hour!".
Maha recommends a charging current of around 0.5 X mAh capacity = 1000 mA for an AA cell rated at 2000 mAh
It's not a good idea to charge the batteries using the radio's internal charging circuit (just a dumb charging circuit, there's no monitoring/regulation of the charging process), it's asking for trouble if something goes wrong (I know this from experience = burning plastic smell and melted battery compartment).
Also, the radio's charging feature treats all the cells as if they're just one battery, if one cell goes bad it compromises the performance of the other cells. An intelligent charger like the Maha charges/monitors each cell individually and via the display data you'll be able to see if one cell is not functioning/charging correctly. The Maha charger will also reject cells that have gone bad.
Get an intelligent charger like the Maha MH-C9000PRO.
That way you can monitor the health of the batteries.
You don't mention what type of rechargeable AA cells you're using, but the Gold Standard AA cells are the Japanese-made Eneloops. Never had an Eneloop battery fail, and I've some that are around 10 years old and still holding a good charge.
Avoid like the plague the various Chinese-manufactured rechargeable AAs, which also includes the major brand names (exception being the Amazon Basics AA cells, made in China now, but seem to be okay), they're crap, as I've also learned from experience.
