Replacement battery pack for HP45

[Richard Hook]

Greetings: Bob Marinelli reported that the Panasonic battery packs HHR-P505 are good replacements for the original battery pack. However, the original battery pack consisted of NiCd cells while the Panasonic pack consists of NiMH cells. Will the original HP charger for the HP 45 be compatible with the NiMH cells or must another charger be used? If the latter is the case, what charger is recommended. Are the Panasonic cells soldered together or do they snap in their battery case?

Thank you for your input

[Dave Shaffer (Arizona)]

I did the HHR-P505 replacement for an even older HP35, and the original charger seems to have no problem putting electrons into the NiMH cells.

The Panasonic cells are prejoined, but you have to bring out their wires to a couple of home-made contacts that take the place of the original battery pack contacts. Make sure you get the polarity correct.

The entire assembly benefits from some strategically placed thin pieces of styrofoam to keep the batteries snug in their new home.