USB Woodstock charger?

[BruceH]

(05-30-2023 03:00 PM)smp Wrote:  But since I've not been paying close attention, I had not yet heard the rule to charge the batteries separately outside the calculator.

This is because there is always a risk that one or both of your batteries, replacement or otherwise, might go bad without warning. And if that happens when the charger is plugged in then there is a chance that the calculator gets damaged.

Much simpler therefore just to avoid that risk completely.