[HOW TO] Notebook Battery Calibration

Discussion in 'Hardware Components and Aftermarket Upgrades' started by blackbird, Jul 23, 2009.

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  1. blackbird

    blackbird Notebook Deity

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    Hope this is the right section for this, even if your battery is not acting up you should still read the note at the end.

    If you'd rather skip the story and get straight on to calibration, read the parts in blue.

    Recently my notebooks battery started acting up, It would go from 100% charge to indicating 5% charge in just under 5 minutes. This caused windows to automatically shut my notebook off in a few minutes, rather annoying.
    After doing some research i found out some possible causes, which are as follows

    - Charger not working properly / does not suit notebooks specs e.g 19V/4.7A
    - Battery requires calibration
    - Battery gone dead
    - Charging system on notebook gone faulty

    The mentioned fixes for each respectively where

    - Try a charger which is known to work (friends laptop etc)
    - Fully charge battery, turn windows powersaving features off, take charger out and let it run till notebook shuts down automatically
    - Try another battery
    - Open notebook up and see if there is rust or connections loose on the charging circuit.

    Now at this time my charger was dead so while i was waiting for a replacement to arrive i eliminated everything by borrowing a friends charger. However the situation was still the same.

    I was hopeful that the calibration could have done the trick as when i turned the power saving features off (screensaver, hibernation, suspend etc) the notebook although still reporting 5% battery in just a few minutes lasted as long as it normally does. After recharging it back up fully I unplugged my notebook hoping for that stupid icon to show a different rate of depletion but still no luck.

    I thought maybe its due to my friends charger having a lower amp rating than my notebooks max but after trying with the replacement charger the results were still the same.

    I wasnt gonna give up, so i did more searching and came upon a helpful page, and downloaded an app they host called BatCal. Its a simple app which basically does the calibration process and times it for you so you don't have to sit at your notebook timing till it powers off.

    The app guides you through the process and uses something called fast discharge or slow discharge the latter is used if you want to work on your notebook whilst the re-calibration is under way.

    So before using the app i put my notebook in presentation mode by right clicking the battery icon and selecting the option in windows mobility center. Right clicked the battery icon, went into power options and set options such as when to turn display off, suspend, hibernate etc to never when using they battery.

    If your on vista/win7 press start, type in cmd, right click it and run with administrator rights then type in this command "powercfg -setdcvalueindex SCHEME_CURRENT SUB_BATTERY BATACTIONCRIT 0" (without quotes) to overide windows default option to shut down on critical battery

    (unchangeable via battery options, thanks to Plex for the tip)

    I then ran BatCal, clicked on begin calibration and it told me that my battery level was 100% and opened the battery options telling me to set the options to never as previously described. It then prompted me to remove my charger and wait till the notebook shuts down automatically.

    Thought it was a good time to hit the gym, came back and found my notebook off. I charged it for an hour or so before turning it back one, played some games on it and waited till it was fully charged, took the charger out and was relived to see that silly icon displaying plausible readings. Ran BatCal again clicked on the results option to see how long it lasted and as noticed before it lasted how long it usually does.

    I don't know/see why using the program as opposed to doing it manually could affect the results. Perhaps they program depletes the battery in a different way or something. Never the less I'm happy my battery is performing as usual and my notebook is back from being a desktop to a laptop.

    I have no idea why I wrote such a big post for something so simple so here it is in short

    - Charge battery fully
    - Turn windows power saving features on battery to never or off
    - Run BatCal
    - Click on begin calibration and follow instructions
    - Do something or stare at the notebook your choice (dont use it)
    - Once its turned off, charge it for an hour before turning back on
    - Turn it back on, let it charge till its full (note how the icon takes longer now to charge up and shows correct readings)
    - Problem hopefully solved, batteries smart memory system reset or whatever.
    - You can set your settings back to what they were now


    Note: I hear its recommended to repeat the calibration process once every few months to ensure its working properly and lasting as long as it should not how much the OS indicates.

    Thanks for reading, hopefully you made it through the post without getting pissed off. If not well tough luck.
    Last edited by a moderator: May 8, 2015
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