On Thu, 07 Feb 2019 21:11:32 +0000, Dave W wrote:

Of course that's the way to do it, but I don't want to, because
"completely empty" means I can't answer it without being liable to be
cut off unexpectedly. When installed the cells were full voltage and
shouldn't have needed charging at all, yet the indicator said empty.

The way around that is to fully discharge the batteries...

A second phone, maybe wired, for the few hours between empty and charged?

Thomas Prufer