Happy Birthday to Me ...

[Bill Duncan]

(01-23-2018 08:04 PM)cjmcc Wrote:  Birthday came, so I was allowed to open the EBay package!
Calculator, case, and reference card all looking good. Battery pack is intact, but I have no idea of the condition of the NICADS or any way to charge them.

(12-31-2017 08:09 PM)Sylvain Cote Wrote:  FYI
Several designers (Nate Martin, Hans Brueggemann, Sven Gugelmann, Dave Frederickson, etc) have created several replacement parts for HP handheld.
For example: Woodstock Battery Top Part & Woodstock Battery Bottom Part
You can order a 3D print copy, from these Shapeways sellers: Nate Martin & Dave Frederickson
Sylvain
Edit: added designer names

I went the single piece approach using Chris Osborne's design, also available on Shapeways from MafWorld . Since the design files were available, I was able to 3-d print the holder, now I just need to figure out a decent spring arrangement to connect the cells and hold them in place. Then I'll add a pair of Eneloops, and hopefully I'm off to the races.

There are a couple of recent threads here on woodstock batteries. One of the threads has a source to springs. The other option mentioned in the threads are doing surgery on the battery pack and replacing the cells. This works for me and has the advantage of coming with a spring already..

Two basic approaches;
- the one I used was to cut one end (the one with the terminals) of the crosspiece out. You can then spread the sides slightly to pull the cells out one-by-one.
- the other approach is to notice how HP did it themselves. Slice the bottom off with an exacto knife.