Is 100% really 100%?
Since I got this new Acer 7739 two months ago, and put Precise on it, the battery indicator has always shown 100% when it was fully charged.
My previous notebook, the Sony VAIO VGN-F140E, showed only 90% after it completed its rechargee. That was good. Charging up your Lithium Ion battery to a full 100% of maximum capacity, combined with discharging it to below 5%, can reduce the battery's useful life by a factor of 2 or more. My Sony, after 3.5 years of repeated charging and discharging still charges up to the full 90% of the designed mwH maximum capacity.
That got me concerned about this Acer. Was the 100% charge also the designed maximum capacity? I checked the hardware and here is the output:
Even though the Battery Monitor app in Precise does not show it, Precise is charging my battery to only 90% of its design capacity, "last full capacity", as it should, to maximize battery life. Also, the "design capacity warning" level, 4290 mWh, is 10% of 43,912 mWh (not 48,400 mWh), and the "design capacity low" level, 2145 mWh, is obviously 5% of the "last full capacity".
I have my battery power settings set to warn me at 10% and to automatically power down at 5%. I also have my lid set to power down this notebook if I close the lid, instead of hybernating or sleeping, to prevent the charge from going below 5%. I have read that a LiIon battery can be reverse polarized on recharging if allowed to fully exhuast its capacity.
So, even though the Battery Monitor in Precise does not display the same figures that it did on my Sony running Lucid, I have don't the mental gymnastics necessary to equate "100% charged" to mean that it is charged to 90% of the maximum design capacity. Barring a physical construction flaw, the batter on this notebook should last for at least a computer generation, or more, just like my Sony battery has.
What really triggered this outburst of curiosity was the release of iPod3 and everyone's amazement at its battery capacity:
The LiIon battery in this 17" Acer 7739 with a six cell battery is only 48.4 wH. That is 87% of the capacity of the battery in this notebook, and it is 1" wide, 1" thick, and about 10" long. :eek: I suspect that Apple has introduced Nano Carbon technology into its batteries.
My previous notebook, the Sony VAIO VGN-F140E, showed only 90% after it completed its rechargee. That was good. Charging up your Lithium Ion battery to a full 100% of maximum capacity, combined with discharging it to below 5%, can reduce the battery's useful life by a factor of 2 or more. My Sony, after 3.5 years of repeated charging and discharging still charges up to the full 90% of the designed mwH maximum capacity.
That got me concerned about this Acer. Was the 100% charge also the designed maximum capacity? I checked the hardware and here is the output:
Code:
cat /proc/acpi/battery/BAT0/info present: yes [B]design capacity: 48400 mWh[/B] [COLOR=#ff0000]last full capacity: 43912 mWh[/COLOR] battery technology: rechargeable design voltage: 10800 mV [B]design capacity warning: 4290 mWh design capacity low: 2145 mWh[/B] cycle count: 0 capacity granularity 1: 484 mWh capacity granularity 2: 484 mWh model number: AS10B31 serial number: battery type: LIon OEM info: OEM jerry@jerry-Aspire-7739:~$ cat /proc/acpi/battery/BAT0/state present: yes capacity state: ok charging state: charged present rate: 0 mW [B]remaining capacity: 43912 mWh[/B] present voltage: 12522 mV
I have my battery power settings set to warn me at 10% and to automatically power down at 5%. I also have my lid set to power down this notebook if I close the lid, instead of hybernating or sleeping, to prevent the charge from going below 5%. I have read that a LiIon battery can be reverse polarized on recharging if allowed to fully exhuast its capacity.
So, even though the Battery Monitor in Precise does not display the same figures that it did on my Sony running Lucid, I have don't the mental gymnastics necessary to equate "100% charged" to mean that it is charged to 90% of the maximum design capacity. Barring a physical construction flaw, the batter on this notebook should last for at least a computer generation, or more, just like my Sony battery has.
What really triggered this outburst of curiosity was the release of iPod3 and everyone's amazement at its battery capacity:
Between the release of the iPad 2 last year and the announcement of the new iPad yesterday, Apple has nearly doubled the capacity of the battery, taking it from 25Wh to a massive 42Wh. Measured in milliamps this boosts the battery from 6944 mAh to a monstrous 11,666 mAh