HP 19C charger

[burkhard]

(10-01-2018 06:30 AM)badaze Wrote:  Of course I know it has to be plugged with the battery pack inside. My question is. As I know those devices are fragile, is there any risk to damage the calculator using the charger ?

Charging the batteries while inside a Woodstock (or Sting) calculator is indeed very risky:
1. If the battery has an internal fault such that it's "open" to the charging circuit, your 19C is ruined.
2. If there's a marginal connection (crud on the connector or whatever) between the battery and the power circuit, your 19C is ruined.
3. If while it's under charge, somebody bumps it hard or it gets knocked off the desk, those couple milliseconds of "open" can mean your 19C is ruined.
4. Even though you yourself know not to attempt running the calculator w/o a battery inside, your family (and/or heirs) do not. So many nice HP calcs of this vintage get smoked because the estate sale picker plugs it in "to see if this old thing still works." It did until 50ms ago...

The safest thing you could do is never buy the OEM charger. If you "need" it for the collection, I would tag it prominently with a warning to never ever use it under any circumstance.

The charging circuit design on the Woodstocks had to be one of HP's dumbest ideas ever. Not warning people about it until page 102 (gee, thanks!) of the manual is a close second. Would a sticker inside the battery compartment (or better yet, on the back) have been so expensive?

Are the Spice series as fragile as the Woodstocks in this regard? I would assume so, but don't know that for sure.