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-   Linux - Hardware (https://www.linuxquestions.org/questions/linux-hardware-18/)
-   -   Is it possible for a battery's life to improve? (https://www.linuxquestions.org/questions/linux-hardware-18/is-it-possible-for-a-batterys-life-to-improve-4175655720/)

Lysander666 06-14-2019 02:43 PM
Is it possible for a battery's life to improve?
 
I inherited this laptop from work, and when I did so, the battery has always been at 95% of its capacity/condition. Nothing wrong with that, 95% is great.

A lot of the time I keep this laptop on suspend but I also give it 'time out' by turning it off.

I regularly check

Code:
inxi -B
which always gives me 95% of battery capacity. However, after another couple of days on and off suspended, I just checked inxi -B and I get

Code:
lysander@lysultra-vi:~$ inxi -B
Battery:  ID-1: BAT0 charge: 53.6 Wh condition: 54.8/55.0 Wh (100%)
Is this possible? Can the battery life actually improve?

ugjka 06-14-2019 02:57 PM
I wonder what the margin of error is like

jefro 06-14-2019 03:26 PM
" Can the battery life actually improve?" In reality the answer is no. A battery starts to go bad the second it gets built. Time and use both play a part in it's destruction.

What you may mean to ask is, "Can the way it is reporting vary?" That answer would be yes.

colorpurple21859 06-14-2019 05:43 PM
I had s cell phone that after bounced lightning strike hit the outside of our mobile home I would have to charge it everday to keep from going dead. I thought for sure I was going to have to replace the battery, but about a year later the phone went back to going four or five days before needing a charge. In my opinion it can happen, but it is rare. But then again it could of something in the phone shorting out that may have burnt open that didn't affect the operation if the phone

Shadow_7 06-14-2019 08:36 PM
It's more likely that reporting changed. Or usage changed with improvements in software. If you turned OFF the laptop for a while and let it change over a duration, it might have gotten more charge. Since the laptop draws from the battery, even when off (RTC clock and whatnot). Or the power connector improved as solder points can degrade when the plug gets pulled and yanked and dropped and whatnot. Like a bad headphone jack, push and pull it a certain way and it's great, but unattended it's anybodies guess.

ondoho 06-15-2019 03:13 AM
It used to be so that chargeable batteries' capacities could be improved through a dedicated discharging/recharging process, specialised chargers used to exist.
I'm not sure if this still applies to newer technologies like in laptops.

In any case, There's a lot of software involved; not only on your OS but also insiode the battery itself - I suspect that (most of) the change originates there.

business_kid 06-16-2019 05:14 AM
Jefro's on the ball here. There's actually a spec quoted in electric cars about how efficient a battery will be at x,000 km. The one figure I hears was 66%, which they thought was good.

zeebra 06-17-2019 07:57 AM
Quote:
Originally Posted by Lysander666 (Post 6005353)
Code:
lysander@lysultra-vi:~$ inxi -B
Battery:  ID-1: BAT0 charge: 53.6 Wh condition: 54.8/55.0 Wh (100%)
Is this possible? Can the battery life actually improve?
Try
Code:
acpi -i
In my experience it is very accurate, over time as well.

Lysander666 06-17-2019 08:00 AM
Quote:
Originally Posted by zeebra (Post 6006274)
Try
Code:
acpi -i
In my experience it is very accurate, over time as well.
Interesting:

Code:
lysander@lysultra-vi:~$ inxi -B
Battery:  ID-1: BAT0 charge: 34.8 Wh condition: 54.8/55.0 Wh (100%)

lysander@lysultra-vi:~$ acpi -i
Battery 0: Discharging, 63%, 09:25:55 remaining
Battery 0: design capacity 7236 mAh, last full capacity 7215 mAh = 99%
I suppose the answer is that we're not totally sure yet, but something is either going on in the reporting or the battery life has actually improved [which seems unlikely, but we would have to rule out its impossibility to go with the former].

I found this comment interesting from a Mac forum:

Quote:
The battery in your macbook pro, will generally have a higher capacity (only very very slightly tho) than when it was manufactured. This is due to the way the chemicals work.

So yes it's perfectly possible for your macbooks battery to ship as say 6900 mah, and then for the next few cycles for the battery capacity to increase to a little over 7000 but will obviously then start to decrease as you continue to use the machine and it gets older

zeebra 06-17-2019 09:00 AM
Quote:
Originally Posted by Lysander666 (Post 6006276)
Interesting:

Code:
lysander@lysultra-vi:~$ inxi -B
Battery:  ID-1: BAT0 charge: 34.8 Wh condition: 54.8/55.0 Wh (100%)

lysander@lysultra-vi:~$ acpi -i
Battery 0: Discharging, 63%, 09:25:55 remaining
Battery 0: design capacity 7236 mAh, last full capacity 7215 mAh = 99%
I suppose the answer is that we're not totally sure yet, but something is either going on in the reporting or the battery life has actually improved [which seems unlikely, but we would have to rule out its impossibility to go with the former].
How do you know it was 95% when you got it? With what tool did you measure that? Perhaps Apple "cheats" and make some kind of secret margin in their software to measure the battery. Perhaps the case is that your measurement with acpi is measuring 100% of the actual battery, and not say 90% as 100% (to try to get the math to work).

54.8wh/55.0Wh seems to be the same as 7215 mAh = 99%.

Or perhaps the previous method you used just isn't the same as this one.

In any case, I feel I can rely on the acpi data.

Lysander666 06-17-2019 09:09 AM
Quote:
Originally Posted by zeebra (Post 6006296)
How do you know it was 95% when you got it? With what tool did you measure that?
I used inxi -B which reported 95% multiple times, as it says in the OP :)

Quote:
Originally Posted by zeebra (Post 6006296)
54.8wh/55.0Wh seems to be the same as 7215 mAh = 99%.
Well, there are two differences: inxi gives 99.64% whereas acpi gives 99.71%. 0.07% is not much of a discrepancy to worry about, I feel. Secondly, inxi rounds up and acpi rounds down.

Quote:
Originally Posted by zeebra (Post 6006296)
In any case, I feel I can rely on the acpi data.
They both seem good to me, but it's interesting to see the differences between the two.

zeebra 06-18-2019 02:39 AM
Quote:
Originally Posted by Lysander666 (Post 6006305)
Well, there are two differences: inxi gives 99.64% whereas acpi gives 99.71%. 0.07% is not much of a discrepancy to worry about, I feel. Secondly, inxi rounds up and acpi rounds down.
By "very" accurate in my case, I mean in percentage without commas. Not sure where inxi gets its data from, but I would guess /sys/class/power_supply/ and acpi gets it from acpi. But where does sys/class/power_supply get its data from? The Kernel? And Kernel is responsible for acpi or just fetch it from the bios directly?

hmm.

pan64 06-18-2019 04:36 AM
actually measuring the quality of the battery is not really possible. So all the used methods are just guessing something based on something else, which can be measured, but unfortunately not really/directly connected to capacity/condition.

tmittelstaedt 06-19-2019 08:44 AM
Battery life and capacity are 2 different things.

Think of it like a 1 quart pitcher of water. It can be 100% full - holding exactly 1 quart. A 1 pint pitcher of water can also be 100% full - holding exactly 1 pint. But if you pour both of them out at the same rate, the quart pitcher will last longer.

As batteries age their capacity gets lower and lower. But even an old battery with a half a pint of capacity left can be charged to 100%.

OF course all of this is academic since the battery specs in a modern laptop battery are supplied by a smart battery chip inside the battery itself which can be programmed to say whatever the heck the battery assembler wants it to say. You can buy a cheap battery from China that has marginal cells in it but the smart chip will happily report lots more capacity than is actually there to make you feel like you "got a deal"

ondoho 06-24-2019 05:01 AM
Quote:
Originally Posted by tmittelstaedt (Post 6007133)
OF course all of this is academic since the battery specs in a modern laptop battery are supplied by a smart battery chip inside the battery itself which can be programmed to say whatever the heck the battery assembler wants it to say.
That's the gist of it really :D


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