Some rechargeable N-Cells I have used in my 41c over the years

[m_a_s]

(04-25-2023 06:27 PM)Dave Britten Wrote:  I've used these on my 41 with pretty good results:

https://www.amazon.com/Tectra-Rechargeab...B096FJKDX3

The 4-pack comes with a single charger, so you have to charge them one at a time, but they're not exactly high capacity, so they charge pretty quick. Alternatively, buy two 4 packs so you get two chargers, and have a spare set you can alternate with.

I use the same batteries in my 28S with no issue. But when I tried to use these in my HP-41CL (has the "chassis" of my dear old HP-41CV that works no more) they don't work.

At first I thought it was the corroded battery tab that I had fixed with a whisker of fine wire and some solder. It's the one that contacts the + battery all the way on the end, not the middle + terminal.

Normal alkaline N cells work fine. Even brands I thought are very "sus". After much fiddling and fussing it turns out that the end + terminal doesn't make good contact with the Tectra or any other rechargeable N cell I had on hand (Anvow and Batmax at the moment). My fix was to solder the nipple of a regular alkaline battery's nipple onto it. It really needs the flange.

I ordered some of the 2/3AAA with flat tops to see if that makes a difference.

Attached photo shows the modified cell (right most) above the battery compartment terminals.