> On Dec 22, 2022, at 4:30 PM, Chuck Guzis <ccl...@sydex.com> wrote:
>
> On 12/22/22 11:42, Paul Koning wrote:
>> 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.
>>
>>
>>
> A good read on the issues of NiMH battery charging can be read here:
>
> https://www.electronics-notes.com/articles/electronic_components/battery-technology/nimh-nickel-metal-hydride-charging.php
>
> It pretty much says that "you're damned if you and damned if you don't".
Yes, that looks similar to what I read. One interesting point in the
discussion I saw is that it said slow charging is not recommended for NiMH
because the right way to detect end of charge is by voltage drop, and that drop
is even smaller if the charge rate is low. So to have reliable detection of
"fully charged" you need to go reasonably fast. Interesting.
paul
