Your point is well taken, Randy.
I did not mean to endorse the extremely poor, incompetent, negligent HP design of the Woodstock battery charging system. I do like the mechanical aspects of the Woodstock battery pack, with its integrated compartment door.
The cheapest Woodstock, the HP-21, cost the equivalent of $494 2008 dollars. I can't imagine why HP thought it would be acceptable to market an expensive product that could be destroyed easily and innocently while connected to the charger if the battery pack was missing, poorly connected, or so degraded as to not provide the charging voltage clamp needed to prevent the spikes that kill the machine.
Whenever I hear fanatical declarations of HP design excellence, I think in response immediately of this Woodstock charging system, the HP magnetic card reader roller, the early Spice series press-fit circuit construction, and the flimsy case, poor battery compartment design, the needlessly complex charger connector plug of all the Spice series, the HP-28 battery door, etc.
I will admit that my 33-year old HP-21 and HP-25 Woodstocks are still going stong today, but likely more from luck than prudent usage. I didn't even know about the charger problems until a few years ago.