The Natural Philosopher wrote:
wrote:

In my (limited) experience, the key words in the PP's post are
"normally plugged in". I know someone who always used their laptop on
mains power. When they came to use it on battery after about a year,
it was next to useless. The Lithium polymer battery in my mobile phone
seems to be going quite well after 3 years plus, and it's only ever on
charge when it needs to be.

Probably best to exercise batteries as they were intended to be used.
Attempts to extend their life by leaving them on permanent charge seem
to be counter productive.

Again, I think its down to the age, and quality of the cells and the
charge regulation circuitry.

Well, that covers all bases ! Not that I would disagree.

Lithium cell actually are best stored at half charge, but they vary
markedly in terms of self discharge, internal resistance and peak power
delivery.

The good news is that its an area of rapid devlopment.

Indeed - apparently Toshiba have some super new technology that permits
1-minute recharge times, although I suspect it may never arrive in the
initially announced form.

--
"VD is nothing to clap about."