Thinking about an HP-41CL

[renif]

Thanks, Dieter, for sharing your insights in this matter and suggesting a more practical solution!

Of course newer charging technology should be used where possible. I keep the old W&W charger only because there is no need for a new one so far and, compact as it is, it also proved to be a lightweight compagnion on travel without taking care of spacers or other small adapter parts.

(07-25-2016 10:55 AM)Dieter Wrote:  This looks like a standard charger for one or two 9 V batteries (6LR61). Their typical capacity (100...120 mAh for NiCds) is quite similar to N-size NiCds of the Eighties, so the charging current should fit. It should be mentioned somewhere on the back of the case. These devices usually offer no charging control at all, maybe at best there is a simple timer, typically set to 14 h.

There are no ratings mentioned on the casing and I don't have a documentation either. But a quick measurement showed a stabilized charging voltage of approx. 5.4 V across fairly depleated cells. If i remenber correctly, there's a potentiometer inside the charger by which this voltage can be changed in a rather narrow range of 2 or 3 V.

Whenever this charger stops working, I definitely go for a processor-controlled device, just as you recommend. Again, thanks!