HP-34C external battery charging

[Dieter]

(12-07-2017 11:35 PM)rprosperi Wrote:  I suggest you instead simply use 'flat-top' NiCd cells, that don't cost much more, for example here.

I agree that flat top cells probably are a good solution. But why do you recommend NiCds instead of NiMHs with 2x or 3x the capacity and virtually no self discharge?

(12-07-2017 11:35 PM)rprosperi Wrote:  These are the same cells as in the original Spice battery pack (you can charge them externally in the smart charger),

If NiCds are used be sure to get a charger with sufficiently low charging current. The mentioned BC700 charger has a lowest (default) current setting of 200 mA which is perfect for 800 mAh NiCds.

(12-07-2017 11:35 PM)rprosperi Wrote:  and insert them into the orginal Spice battery pack frame (held with scotch tape) and simply use a folded aluminim foil conductor for the far end as Dieter noted.

For the record: I do not use the original battery pack frame, just two standard Sanyo/Panasonic AA Eneloops and a piece of folded aluminum foil. Works fine here.

Dieter