> On Dec 22, 2022, at 11:49 AM, Chuck Guzis via cctalk <cctalk@classiccmp.org>
> wrote:
>
> I can't speak with any authority on the NiMH vs. NiCd substitution,
> except that I've replaced them on low-draw devices and used the same
> charger. After 20 years of doing this, I can't claim to have destroyed
> any NiMH, though I can certainly appreciate the self-limiting of
> overcharge on NiCd cells.
I just read the battery chapter of the ARRL Amateur Radio Handboo, which
discusses this particular point at some length.
Among many other points it says (a) you can trickle charge a NiCd but not a
NiMH, and (b) NiMH requires a more complex charging algorithm than NiCd, so
that NiMH chargers are also capable of charging NiCd batteries safely, but NiCd
chargers cannot charge NiMH cells without the risk of damage.
I suspect NiMH charger circuits can be found. Buying $3 Chinese ones may work,
or not; I keep remembering that China disallows selling unsafe equipment within
the country but doesn't have any rules against exporting such things.
paul
