On 01/02/2021 17:49, Tim Streater wrote:
On 01 Feb 2021 at 16:31:54 GMT, Peter Able wrote:

On 01/02/2021 13:50, Reentrant wrote:
On 01/02/2021 07:30, Brian Gaff (Sofa) wrote:
No.
Â*Â* Depends on the number of cells and what type of battery they are
and to
some extent on how cheap the device is. Charging in series is hardly
every a
good way to preserve life.
Â* Brian

Brian, Braun toothbrushes use wireless, high-frequency inductive charging.

We upgraded from an older NiMH toothbrush to a new Li-ion one and the
existing wall-mounted charger/head holder worked fine.

About 20-50kHz

Not sure I'd call it wireless. Just a loosely coupled transformer. Small
because it's not 50Hz. :-)


https://en.wikipedia.org/wiki/Inductive_charging

"...also known as wireless charging... ... electric toothbrushes ..."

Feel free to edit the article if it's wrong.


--
Reentrant