On Mon, 23 Dec 2019 22:29:40 GMT, Pamela
wrote:

On 19:42 23 Dec 2019, T i m wrote:

On Mon, 23 Dec 2019 16:49:00 GMT, Pamela
wrote:

snip

I wouldn't leave a lithium ion battery on charge the whole time because
a full charge stresses the battery and shortens its life,

Whilst it does, it's a toss up between (and already short) run-time in
use and battery life.

Some laptops (and some (/most / all?) EV's, have the ability to limit
the maximum charge to say 80% (of maximum capacity) to make the battery
last longer, at the expense of a shorter run-time.

The minimum charge cutoff is pretty common on most BMS's, including the
cells themselves in some cases.


As I understand it, manufacturers design the charging cutoff to allow the
maximum charge in order to satisfy consumers who demand the longest runtime
possible.

Yes, except manufacturers of EV's and (some that I know of) laptops
.... and who knows what else?

My point here is that unless we know what's going on behind the
scenes, we can only assume how the charging is managed.

I'm currently working on a Samsung laptop for a friend and I noticed
that has an option in the BIOS to limit the maximun charge to 80% to
prolong the battery life. How many other laptops (or phones etc) may
also give you the option or do it by default?

I think Tesla will sell you a replacement EV battery at a much reduced
cost if you are able to get the existing one up to a specific number
of miles / years. To do this the owner would have to manage the
battery carefully and that might include ensuring the max and min
charge levels are not exceeded. Obviously they want owners to get the
maximum lifespan out of their batteries as it looks good on their PR
and is likely to reduce any warranty claims (compared when the battery
is used 'hard').

Cheers, T i m