Laptop battery charging?...

[Dean Hoffman]

I recently bought a new MacBook Air. There are all sorts
of tips about extending
the duration of a single charge. Does it matter when I charge it if I
want to get the
battery\'s life to be the longest? Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

 

[Chris Jones]

On 06/10/2020 22:33, Dean Hoffman wrote:

           I recently bought a new MacBook Air.   There are all sorts
of tips about extending
the duration of a single charge.    Does it matter when I charge it if I
want to get the
battery\'s life to be the longest?  Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

Not sure about when to start charging it, but you should set it to stop
charging before it gets to maybe 80% (mine is set to stop at 60%), to
prevent the cell voltage getting into the range that causes degradation.

As far as I know the decision about when to start it charging is mostly
determined by how much charge you want to have available in the event
that you unexpectedly need to use it for a while without mains power. I
set mine to start charging at 50% and stop at 60%, but since it is used
on AC power it very rarely charges.

Letting it stay near completely empty might be a bad idea, since if you
forget about it or are unable to access it for a while, the battery
could get into deep discharge, in which case it is bricked as the
controller will refuse to charge it ever again for safety reasons, or
\"safety reasons\".

 

[legg]

On Tue, 6 Oct 2020 06:33:00 -0500, Dean Hoffman <deanhofman@clod.com>
wrote:

I recently bought a new MacBook Air. There are all sorts
of tips about extending
the duration of a single charge. Does it matter when I charge it if I
want to get the
battery\'s life to be the longest? Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

If Li-Ion, you\'ve got x number of charge cycles in the battery\'s life,
before capacity is reduced to 50% of its label rating. Keep it plugged
in and charging/charged, whenever you don\'t need portability.

RL

 

[Martin Brown]

On 06/10/2020 12:33, Dean Hoffman wrote:

           I recently bought a new MacBook Air.   There are all sorts
of tips about extending
the duration of a single charge.    Does it matter when I charge it if I
want to get the
battery\'s life to be the longest?  Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

Maximising number of charge cycles will probably get the optimum use.

Rules of thumb are:

Never leave it flat for an extended period.
Ideally don\'t leave it on charge continuously either.

Modern batteries claim no to have significant memory effect but even so
once in a while it does no harm to take the charge down to the last 5%
or so. Only crash into the shutdown end stop if you must keep working.

There seems to be a marginal gain in battery lifetime by allowing the
battery to cool down before connecting the charger. This applies more to
power tools and vacuum cleaners. Laptop current draw isn\'t anything like
as brutal. Cells too hot to touch are too hot to charge well.

--
Regards,
Martin Brown

 

[Ricketty C]

On Tuesday, October 6, 2020 at 7:33:11 AM UTC-4, Dean Hoffman wrote:

I recently bought a new MacBook Air. There are all sorts
of tips about extending
the duration of a single charge. Does it matter when I charge it if I
want to get the
battery\'s life to be the longest? Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

I have an app for my phone that seems to indicate the same sort of constraints as Tesla advises for their cars. To maximize the life span of the battery avoid the bottom 10%-15% of the battery state of charge and the top 10%-25%. Tesla has a charging setting image with lines at 80% and 90% marked \"Trip\" implying you should not charge above this level unless you are going on a trip and need the extra range.

My phone app goes so far as to provide charging advice based on battery life. It seems show charging between ~25% and 75% results in wear of around 14% of a \"full\" charge. Starting at a lower level than 25% increases the \"wear\" a bit but charging beyond the 75% level increases the wear more rapidly in an increasing scale.

I believe the \"wear\" is a result of the lithium ions intercalating into the anode and the resulting mechanical expansion. This process slows down at higher charge levels which results in lithium plating onto the anode more readily. That\'s a bad thing. The mechanical expansion issues also play a role although I\'ve not seen that described in much detail. I seem to recall a number of 10% expansion at full charge which seems a lot, so my memory may not be right. Bill seems to know a lot about batteries. Maybe he will know.

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

On Tuesday, October 6, 2020 at 7:58:07 AM UTC-4, Chris Jones wrote:

On 06/10/2020 22:33, Dean Hoffman wrote:

           I recently bought a new MacBook Air.   There are all sorts
of tips about extending
the duration of a single charge.    Does it matter when I charge it if I
want to get the
battery\'s life to be the longest?  Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

Not sure about when to start charging it, but you should set it to stop
charging before it gets to maybe 80% (mine is set to stop at 60%), to
prevent the cell voltage getting into the range that causes degradation.

As far as I know the decision about when to start it charging is mostly
determined by how much charge you want to have available in the event
that you unexpectedly need to use it for a while without mains power. I
set mine to start charging at 50% and stop at 60%, but since it is used
on AC power it very rarely charges.

Letting it stay near completely empty might be a bad idea, since if you
forget about it or are unable to access it for a while, the battery
could get into deep discharge, in which case it is bricked as the
controller will refuse to charge it ever again for safety reasons, or
\"safety reasons\".

I saw a video of an Australian gent who showed how to \"revive\" power tool battery packs. He was simply using a good battery pack to put some charge on an exhausted battery pack using two pair of scissors to bridge them. Seems the batteries have nothing that breaks the connection to the terminals. Once the battery had enough charge (~1 minute of \"charging\") the charger would recognize it and finish the job.

--

Rick C.

+ Get 1,000 miles of free Supercharging
+ Tesla referral code - https://ts.la/richard11209

 

[Ricketty C]

On Tuesday, October 6, 2020 at 8:53:25 AM UTC-4, legg wrote:

On Tue, 6 Oct 2020 06:33:00 -0500, Dean Hoffman <deanhofman@clod.com
wrote:


I recently bought a new MacBook Air. There are all sorts
of tips about extending
the duration of a single charge. Does it matter when I charge it if I
want to get the
battery\'s life to be the longest? Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

If Li-Ion, you\'ve got x number of charge cycles in the battery\'s life,
before capacity is reduced to 50% of its label rating. Keep it plugged
in and charging/charged, whenever you don\'t need portability.

Charging between two states of charge other than a full charge puts much less wear on the battery. A charge from 25% to 75% is around 14% of a full charge according to my phone app.

Heck, I just found out why my phone didn\'t wake me up this morning... it\'s out of charge. Starting at 5% the app says charging to 75% will put 17% of a cycle wear on it. So the low end doesn\'t seem to matter as much as the high end.

--

Rick C.

-- Get 1,000 miles of free Supercharging
-- Tesla referral code - https://ts.la/richard11209

 

[Dean Hoffman]

On 10/6/20 6:33 AM, Dean Hoffman wrote:

           I recently bought a new MacBook Air.   There are all sorts
of tips about extending
the duration of a single charge.    Does it matter when I charge it if I
want to get the
battery\'s life to be the longest?  Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

I did a little more research.
<https://support.apple.com/en-us/HT211094?cid=mc-ols-energy_saver-article_ht211094-macos_ui-04022020>
The people at Apple added battery management to macOS Catalina 10.15.5
I didn\'t see anything in the articles that answered my question.

I forgot to say thanks the
first time around

 

[gray_wolf]

On 06/10/2020 6:57 am, Chris Jones wrote:

On 06/10/2020 22:33, Dean Hoffman wrote:

            I recently bought a new MacBook Air.   There are all sorts of tips
about extending
the duration of a single charge.    Does it matter when I charge it if I want
to get the
battery\'s life to be the longest?  Should I charge it when the battery is at
50%, 25%, or
maybe let it run down to shutdown?

Not sure about when to start charging it, but you should set it to stop charging
before it gets to maybe 80% (mine is set to stop at 60%), to prevent the cell
voltage getting into the range that causes degradation.

As far as I know the decision about when to start it charging is mostly
determined by how much charge you want to have available in the event that you
unexpectedly need to use it for a while without mains power. I set mine to start
charging at 50% and stop at 60%, but since it is used on AC power it very rarely
charges.

Letting it stay near completely empty might be a bad idea, since if you forget
about it or are unable to access it for a while, the battery could get into deep
discharge, in which case it is bricked as the controller will refuse to charge
it ever again for safety reasons, or \"safety reasons\".

Is leaving my new Dell laptop constantly in the charging mode, even when not in
use, a bad idea?

 

[Ricketty C]

On Tuesday, October 6, 2020 at 11:40:42 PM UTC-4, gray_wolf wrote:

On 06/10/2020 6:57 am, Chris Jones wrote:
On 06/10/2020 22:33, Dean Hoffman wrote:

            I recently bought a new MacBook Air.   There are all sorts of tips
about extending
the duration of a single charge.    Does it matter when I charge it if I want
to get the
battery\'s life to be the longest?  Should I charge it when the battery is at
50%, 25%, or
maybe let it run down to shutdown?

Not sure about when to start charging it, but you should set it to stop charging
before it gets to maybe 80% (mine is set to stop at 60%), to prevent the cell
voltage getting into the range that causes degradation.

As far as I know the decision about when to start it charging is mostly
determined by how much charge you want to have available in the event that you
unexpectedly need to use it for a while without mains power. I set mine to start
charging at 50% and stop at 60%, but since it is used on AC power it very rarely
charges.

Letting it stay near completely empty might be a bad idea, since if you forget
about it or are unable to access it for a while, the battery could get into deep
discharge, in which case it is bricked as the controller will refuse to charge
it ever again for safety reasons, or \"safety reasons\".

Is leaving my new Dell laptop constantly in the charging mode, even when not in
use, a bad idea?

It is a bad idea for the laptop makers to not design in proper battery management. The problem is not so much leaving it plugged in since it doesn\'t charge once the battery is fully topped off. It\'s the fact that the battery is always fully topped off that is bad for it. They should leave the battery at 75%-80% most of the time, but then you would need to tell it when you plan to use it off battery so it could then top it off before hand. That is really inconvenient for a computer. Works pretty well for a car though.

Tesla still has not factored in that some customers have TOU (Time of Use) utility plans and need to not charge during specific times. They have a timer to start charging, but not one to end it. Alternatively, you can schedule the time when the car will be fully charged and the car will start charging automatically, but it will start according to the charge level even if it is in the time window of high electrical charges.

Tesla does a lot of good things, but there are a lot of details they have yet to figure out.

--

Rick C.

-+ Get 1,000 miles of free Supercharging
-+ Tesla referral code - https://ts.la/richard11209

 

[Martin Brown]

On 07/10/2020 04:40, gray_wolf wrote:

On 06/10/2020 6:57 am, Chris Jones wrote:
On 06/10/2020 22:33, Dean Hoffman wrote:

            I recently bought a new MacBook Air.   There are all
sorts of tips about extending
the duration of a single charge.    Does it matter when I charge it
if I want to get the
battery\'s life to be the longest?  Should I charge it when the
battery is at 50%, 25%, or
maybe let it run down to shutdown?

Not sure about when to start charging it, but you should set it to
stop charging before it gets to maybe 80% (mine is set to stop at
60%), to prevent the cell voltage getting into the range that causes
degradation.

As far as I know the decision about when to start it charging is
mostly determined by how much charge you want to have available in the
event that you unexpectedly need to use it for a while without mains
power. I set mine to start charging at 50% and stop at 60%, but since
it is used on AC power it very rarely charges.

Letting it stay near completely empty might be a bad idea, since if
you forget about it or are unable to access it for a while, the
battery could get into deep discharge, in which case it is bricked as
the controller will refuse to charge it ever again for safety reasons,
or \"safety reasons\".

Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?

Yes. I have destroyed several laptop batteries that way. But my reason
for leaving them on power continuously is that they mostly were being
used as a desktop computer and run faster when on mains power.

Keeping the bettery brim full for long periods of time does irreversible
damage to the cell chemistry and like all stacks of individual cells the
weakest one in the chain is ruined by the others when it is discharged.

It is much worse to leave it with a flat battery for an extended period.

--
Regards,
Martin Brown

 

[legg]

On Tue, 6 Oct 2020 21:49:02 -0500, Dean Hoffman <deanhofman@clod.com>
wrote:

On 10/6/20 6:33 AM, Dean Hoffman wrote:

           I recently bought a new MacBook Air.   There are all sorts
of tips about extending
the duration of a single charge.    Does it matter when I charge it if I
want to get the
battery\'s life to be the longest?  Should I charge it when the battery
is at 50%, 25%, or
maybe let it run down to shutdown?

I did a little more research.
https://support.apple.com/en-us/HT211094?cid=mc-ols-energy_saver-article_ht211094-macos_ui-04022020
The people at Apple added battery management to macOS Catalina 10.15.5
I didn\'t see anything in the articles that answered my question.

I forgot to say thanks the
first time around

It\'s often a mistake to let the software guys get involved
with battery management. It\'s less a mistake if the HW mfr
does it - they at least have some control over the battery
chemistry and vendor source being selected for use and a
familiarity with the application load.

Battery mfrs are the most logical people to turn to for this
type of information, but in a competative market, they can
be cagey about releasing information that is not filtered
through a sales network.

Unless you\'re in a position to build or program your own
charging system, all you can use this info for is to determine
if there\'s a suitable marriage between the battery and its
application.

Letting the end-user program charging and discharging limits
and profiles may make everybody feel better, but it won\'t
necessarily produce the longest battery service life.

RL

 

[Chris]

On 10/07/20 04:40, gray_wolf wrote:

Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?

Don\'t know about Dell, but the older Panasonic Toughbooks here
have circuitry and software support to prevent damage if the
machine is plugged into the line all the time. That is, they
exp3ct users to do that.

These were not bought new either, too expensive, but made up
from various broken, spares examples...

Chris

 

[Martin Brown]

On 07/10/2020 14:03, Chris wrote:

On 10/07/20 04:40, gray_wolf wrote:

Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?

Don\'t know about Dell, but the older Panasonic Toughbooks here
have circuitry and software support to prevent damage if the
machine is plugged into the line all the time. That is, they
exp3ct users to do that.

These were not bought new either, too expensive, but made up
from various broken, spares examples...

The requirement for specsmanship longevity in various consumer run down
tests drives some creative accounting in the battery capacity. You can
get a longer runtime by allowing the battery to charge right up to its
absolute safe maximum capacity but there are diminishing returns.

The only way to tell is if the thing has no battery capacity remaining
when it is not on mains power (like my own Samsung 17\" portable now).
Hazards of using it for fast computations as a second desktop machine.

It is long enough in the tooth that it isn\'t worth replacing the battery
- particularly not since Covid prevented any travelling with it. On the
move these days I make do with a much smaller lighter 11\" unit.

--
Regards,
Martin Brown

 

[gray_wolf]

On 07/10/2020 8:03 am, Chris wrote:

On 10/07/20 04:40, gray_wolf wrote:


Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?



Don\'t know about Dell, but the older Panasonic Toughbooks here
have circuitry and software support to prevent damage if the
machine is plugged into the line all the time. That is, they
exp3ct users to do that.

These were not bought new either, too expensive, but made up
from various broken, spares examples...

Chris

Thanks for the reply. I kept my 5 yr old android on and charging for several
months. The battery became swollen so bad the back would no longer close
but it still works. Sister got me a new Samsung which is a big improvement.

Ken

 

[Ricketty C]

On Wednesday, October 7, 2020 at 1:43:59 PM UTC-4, gray_wolf wrote:

On 07/10/2020 8:03 am, Chris wrote:
On 10/07/20 04:40, gray_wolf wrote:


Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?



Don\'t know about Dell, but the older Panasonic Toughbooks here
have circuitry and software support to prevent damage if the
machine is plugged into the line all the time. That is, they
exp3ct users to do that.

These were not bought new either, too expensive, but made up
from various broken, spares examples...

Chris



Thanks for the reply. I kept my 5 yr old android on and charging for several
months. The battery became swollen so bad the back would no longer close
but it still works. Sister got me a new Samsung which is a big improvement.

Swollen batteries are dangerous. Lithium batteries can catch fire and a swollen battery is much more likely to have that happen.

The charging would only have caused this if the internal charging circuit was defective. Much more likely it was caused by the 5 year age.

--

Rick C.

+- Get 1,000 miles of free Supercharging
+- Tesla referral code - https://ts.la/richard11209

 

[Lasse Langwadt Christensen]

onsdag den 7. oktober 2020 kl. 20.30.26 UTC+2 skrev Ricketty C:

On Wednesday, October 7, 2020 at 1:43:59 PM UTC-4, gray_wolf wrote:
On 07/10/2020 8:03 am, Chris wrote:
On 10/07/20 04:40, gray_wolf wrote:


Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?



Don\'t know about Dell, but the older Panasonic Toughbooks here
have circuitry and software support to prevent damage if the
machine is plugged into the line all the time. That is, they
exp3ct users to do that.

These were not bought new either, too expensive, but made up
from various broken, spares examples...

Chris



Thanks for the reply. I kept my 5 yr old android on and charging for several
months. The battery became swollen so bad the back would no longer close
but it still works. Sister got me a new Samsung which is a big improvement.

Swollen batteries are dangerous. Lithium batteries can catch fire and a swollen battery is much more likely to have that happen.

The charging would only have caused this if the internal charging circuit was defective. Much more likely it was caused by the 5 year age.

yeh, I replaced mine and took the old swollen one outside and poked a hole
in it, it took off spewing fire like a piece of fireworks ...

 

[Lasse Langwadt Christensen]

onsdag den 7. oktober 2020 kl. 10.37.10 UTC+2 skrev Martin Brown:

On 07/10/2020 04:40, gray_wolf wrote:
On 06/10/2020 6:57 am, Chris Jones wrote:
On 06/10/2020 22:33, Dean Hoffman wrote:

            I recently bought a new MacBook Air.   There are all
sorts of tips about extending
the duration of a single charge.    Does it matter when I charge it
if I want to get the
battery\'s life to be the longest?  Should I charge it when the
battery is at 50%, 25%, or
maybe let it run down to shutdown?

Not sure about when to start charging it, but you should set it to
stop charging before it gets to maybe 80% (mine is set to stop at
60%), to prevent the cell voltage getting into the range that causes
degradation.

As far as I know the decision about when to start it charging is
mostly determined by how much charge you want to have available in the
event that you unexpectedly need to use it for a while without mains
power. I set mine to start charging at 50% and stop at 60%, but since
it is used on AC power it very rarely charges.

Letting it stay near completely empty might be a bad idea, since if
you forget about it or are unable to access it for a while, the
battery could get into deep discharge, in which case it is bricked as
the controller will refuse to charge it ever again for safety reasons,
or \"safety reasons\".

Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?

Yes. I have destroyed several laptop batteries that way. But my reason
for leaving them on power continuously is that they mostly were being
used as a desktop computer and run faster when on mains power.

Keeping the bettery brim full for long periods of time does irreversible
damage to the cell chemistry and like all stacks of individual cells the
weakest one in the chain is ruined by the others when it is discharged.

It is much worse to leave it with a flat battery for an extended period.

Lenovo,

https://forumscdn.lenovo.com/old_attach/120272i5CC4D15CE4F14453.jpg

 

[Chris]

On 10/07/20 20:04, Lasse Langwadt Christensen wrote:

onsdag den 7. oktober 2020 kl. 20.30.26 UTC+2 skrev Ricketty C:
On Wednesday, October 7, 2020 at 1:43:59 PM UTC-4, gray_wolf wrote:
On 07/10/2020 8:03 am, Chris wrote:
On 10/07/20 04:40, gray_wolf wrote:


Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?



Don\'t know about Dell, but the older Panasonic Toughbooks here
have circuitry and software support to prevent damage if the
machine is plugged into the line all the time. That is, they
exp3ct users to do that.

These were not bought new either, too expensive, but made up
from various broken, spares examples...

Chris



Thanks for the reply. I kept my 5 yr old android on and charging for several
months. The battery became swollen so bad the back would no longer close
but it still works. Sister got me a new Samsung which is a big improvement.

Swollen batteries are dangerous. Lithium batteries can catch fire and a swollen battery is much more likely to have that happen.

The charging would only have caused this if the internal charging circuit was defective. Much more likely it was caused by the 5 year age.


yeh, I replaced mine and took the old swollen one outside and poked a hole
in it, it took off spewing fire like a piece of fireworks ...

I have a laptop that is always on, 24x7, running a vt100 terminal
emulator, but don\'t have the battery fitted, just gets plugged in
every few weeks to top up, Rubs fine without it...

Chris

 

[Clifford Heath]

On 8/10/20 12:12 am, Martin Brown wrote:

On 07/10/2020 14:03, Chris wrote:
On 10/07/20 04:40, gray_wolf wrote:

Is leaving my new Dell laptop constantly in the charging mode, even when
not in use, a bad idea?

Don\'t know about Dell, but the older Panasonic Toughbooks here
have circuitry and software support to prevent damage if the
machine is plugged into the line all the time. That is, they
exp3ct users to do that.

The only way to tell is if the thing has no battery capacity remaining
when it is not on mains power (like my own Samsung 17\" portable now).
Hazards of using it for fast computations as a second desktop machine.

I don\'t doubt your claims, but I have had three MacBooks over the last
14 years, and all have been used daily and almost always on the power
adapter - yet all have lived for some years and appeared to still have
great battery life on the occasions I had to work on battery.

So there\'s at least one contrary data point.

Clifford Heath.