Acer extensa 5220 battery issues

Hi all, first post here on forum
In a nutshell i have an Acer extensa 5220 laptop which is about 14 months old since purchased new. Lately the battery has become useless, for the simple fact if i charge it it lasts for about 3-4 minutes tops then laptop shutsdown.

I have battery monitoring software that tells me that when the battery is fully charged and holding 13320mwh and capacity is 13320mwh and voltage is 12607mv. it is lithium Ion battery made by Sony.
When disconnecting from AC power the battery meter tells me i have approx 50 minutes of battery life when at 99%. in approx 2 minutes the battery meter shows 91% and 28 minutes battery life. then from 91% the meter goes straight to 7% battery life and low power critical battery alarm comes up. then within about 1 minute the unit shuts down. When the critical battery alarm activates, my battery voltage reads below 11volts and the capacity is down in the low hundreds. there is a gap of between 11000mwh to 500mwh that has disappeared from the battery. is this a software issue causing the battery to think its fully charged, because the system says it is? I also notice when charging the battery it increases the charge % up to 16% then goes straight to 100% and says its fully charged.

Please can some one give me advice. PS: i have had the battery pack apart and individually tested each Lithium Ion cell and all pulled even good voltage of about 4.19V on a volts meter.

 

Sounds like a faulty cell to me. Measuring voltage isn't a true test, as the cell is unloaded. It's the internal resistance that rises and essentially prevents the cell from supplying current.
Measure any battery off load and the voltage will appear near normal.

 

you need to recaliberate your battery. Like every battery, LI-Ion also suffer from memory issue. The battery capacity will degrade over time - this is normal for batteries.



Battery Calibration Procedure:

As the battery degrades, Windows will indicate an incorrect battery life for your notebook. This can be corrected by calibrating the battery:

1) Plug in AC adapter and charge battery until 100% full
2) When battery is full, restart the laptop and enter the BIOS setup screen
(F2)
3) Once in the BIOS setup screen, unplug AC Adapter
4) Let the laptop drain itself completely until battey is completely dead.

Be sure not to plug in the AC adapter or turn off the screen. The intent is to let the laptop run and drain itself without any power management feature being kicke it (that is why u are in the BIOS and not WINdows)

 

Oh yeah the reason why your battery fails is because of the memory effect. Your laptop is constantly plugged into the AC adapter or you always charge the battery when it is 50-90% ful.