John Laird wrote:
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.
yeah..I wouldn't say that that particular cell is either more than
vapourware, or actually any use apart from possible automotive
applications. BEVs need to get down to about 3-5 minute recharge times -
of at least 70-80% capacity anyway - without sever loss of efficiency
and damage.
But of the 7 or 8 lithium packs I have that fly my model planes, the
very worst one on power delivery.. it gets hot and loses power if used a
high power (20A on a 2000mAh pack) continuously..is the very best on
charge retention.
Some of the high discharge ones are a lot worse..and don't seem to be
lasting well either.
So it would seem that there are many micro adjustments to cell
construction and chemistry that can optimise in different directions,
but not ALL directions.
But anyway they are streets ahead of nickel cells in every respect
except the ability to go flat and survive, the recharge times and the
cost.