Protection Circuitry ?

[W6GQ]

I have the Yaesu FT-817ND and it comes with the battery tray (FB-28) to use 8 AA Alkaline batteries.

I just bought 8 rechargable AA Ni-MH batteries and THEN decided to read the manual which states the following:

Do not attempt to use Ni-Cd or other rechargeable cells in the FBA-28, because it does not contain the protection circuitry required when using rechargeable
cells.

DAMN!! What circuitry is there for alkalines but not rechargables?

I do not plan on charging them in the radio. I have a seperate charger for that.

I am cornfused

Is there no way I can use the rechargables with this rig?

[KE5FRF]

I'm PRETTY sure they are just warning you not to try to recharge the batteries while installed in the rig...i.e. hooking up your 12 volt supply to the rig and expecting a recharge. I seriously DOUBT that installing precharged NiCads in the thing will hurt a thing. Voltage is voltage.

BUT I COULD BE WRONG. Maybe someone else will have something to add.

[N4CR]

You will find your answer here:

http://www.w4wb.com/Manuals/FT817-FAQ.pdf

[M0DSZ]

NiCad and NiMh cells have a much lower internal resistance than alkaline so in the event of a serious fault something might fry. I suppose this implies a suitable fuse somewhere.
As far as charging them goes, you need to limit the charging current. An excellent and simple constant current regulator can be made from any 3-terminal regulator (12V for example). I think the National Semiconductor website still provides this somewhere, it's just a regulator and 2 or 3 resistors.