Re: Issue with notebook (maybe the battery?)
On Sun, 26 Mar 2017 12:07:46 +0200
<tomas@tuxteam.de> wrote:
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> On Sun, Mar 26, 2017 at 04:46:37AM -0500, Richard Owlett wrote:
> > On 03/25/2017 05:29 PM, Daniel Bareiro wrote:
> > >Hi, Joe.
> > >
> > >[snip]
> > >
> > >Checking the purchase invoices, I bought the notebook on September
> > >19, 2013, and then changed the battery on November 2, 2015. So
> > >less than two years ago I have this battery.
> > >
> > >The notebook I use it practically every day and I leave it
> > >sleeping from one day to the next so I do not have to open every
> > >application every time. I'm not sure if that impacts so much on
> > >the battery life.
> >
> > If it was a long term degradation, possibly. With some battery
> > technology/technologies(?) there is a "memory" effect. If there is a
> > repeated "shallow discharge"/recharge cycle ( sleep overnight
> > followed by running during day with charger plugged in) the
> > effective battery capacity will decrease. IIRC that applies to only
> > one technology but can't remember which.
>
> That would be the nickel family (NiMH and its predecessors). Laptops
> changed long ago (I'd venture somewhere in the 90-ies) to Li-whatever.
Lithium isn't particularly sensitive to state and depth of charge,
apparently the optimal long-term storage state is about half-charge.
>
> Those have other weak spots: overcharging shortens their lives,
> especially being overcharged *and* higher temps. More overcharging
> leads to fireworks. They *need* some electronics to take care of
> that. Deep discharge is also fatal to their lifetimes.
Complete discharge is instantly fatal, they can never wake up again.
All lithium cells have rudimentary electronics to cut off discharge
earlier than this, typically 2.8-3.0V per cell. Charging is relatively
complex, constant current of about half capacity to around 4.1V, then
constant voltage to fairly precise 4.2V, then when the current drops
below a certain level, cutoff.
It should be possible to leave a lithium battery permanently connected
to the charger. No 'trickle charge' will occur, no additional current
will flow until the cell voltage drops by a certain amount. But full
charge is not recommended for long-term storage.
Yes, I had to build a lithium battery into something a few years ago,
I had to learn how to charge it.
--
Joe
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