HP-41 Batteries

[klacombe]

Thanks Geoff, I'm sure I'm one of many (im)patiently waiting for your book release. One of the sources for cells (both 1/3AAA and 2/3AAA) that I found is Pololu. They sell pre-soldered packs for use in things like RC vehicles. Much cheaper than buying individual tabbed cells and most of the work is already done for you. They do not have the set of 4 1/3AAA in stock so I went with 2 sets of 6 cells and was able to create 2 sets of 4. Connected, mine charge in the pack with the standard AC adapter but I'm not happy with the fit so I am looking at other options. They are a hair longer than the original 1/2N cells which makes for a tight fit with the two spring loaded contacts!