Battery weirdness

[grumpy]

Over the past couple of weeks (prior to the Dec update), I have notice some strange battery related issues with my SP2.

First, I started noticing that when the battery was fully charged, the battery level indicator would not change until it dropped to 97%. Sometimes it briefly showed 99% or 98% but then jumped back to 100%. In HwInfo64, the remaining capacity did not decrease until hitting 97% and then it dropped by what appeared to be the correct amount.

Secondly, my SP2 seems to want to hibernate when the battery hits 9%. I can wake it up but it will spontaneously hibernate again in a few minutes. My SP2 is set to hibernate when the battery reaches 5%. I changed this to 3% and it seemed to hibernate at 6%.

Thirdly, my battery level indicator seems to like to reset to 100%. I could be at 75% when I put it to sleep, but the next time it wakes up it may say it is at 100%. This is one issue that seem rather prevalent. I have read about holding the "volume +" and power button. While this worked to restore the proper capacity, a few days latter the problem returned.

And now for the weirdest issue. My battery indicator will drop from 25% to 21%. I even logged this behavior with hwinfo. The remaining capacity instantaneously dropped from about 10,000mWh to 8700mWh. The same thing also happens when charging - a jump from about 8700mWh to 10,000mWh. It is bad enough that after about two months my rated capacity has dropped nearly 2500mWh, but now there is a 1300mWh "hole" in my battery...:shocked:


I will probably try and pursue a replacement with MS after the holidays. My SP2 also has developed a case of CSS (Crunchy Screen Syndrome)...:disappointed:

I do like the Surface and bought the SP2 (256GB) as a result of my positive experience with the SP1.

 

[hotphil]

You might be putting too much faith in the accuracy of the battery measurements.

 

[Arizona Willie]

Yes the battery app included is a joke.

Hopefully the battery report generated from the command prompt is more accurate.
I also have the battery bar app ( free ) and it disagrees with the app that came installed by almost an hour sometimes, as to the amount of time left.
Strangely, the percent of charge always agrees pretty well but the time left is insanely different between the two.

And the tell you to run the battery down every so often ( read that somewhere ) but you CAN'T.
My Surface Pro shuts off automatically at about the 10% point.
So it makes it impossible to drain the battery lower than that.
Perhaps there is a way to override that, I dunno.

You might be putting too much faith in the accuracy of the battery measurements.

 

[grumpy]

I have been using hwinfo to monitor the battery capacity. There is definitely something odd going on. Coming from the SP1, I did not experience these issues. As far as I know, the SP1 and SP2 use the same battery.

Hmmmm... My battery meter just reset again...It seems to be resetting every time it sleeps.

Also, while using hwinfo, I noticed that the minimum battery voltage is about 3V. The battery should never drop below 6V. I guess that this could just be a "sensor error"...