Greetings from Germany

[Sylvain Cote]

(07-25-2019 07:53 PM)Thott Wrote:  What I am still looking for is a rechargeable battery pack for the HP41 for renewing with new batteries.

I would suggest to use NiMh N batteries instead of a battery pack, you will have more autonomy.
For ~$12.00 USD you can have 4 x N batteries rated at 600 mAh (look here).
I use a smart charger like this one to recharge these batteries.