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Solved Weird battery drain

Good Afternoon all, something strange has been happening to my SP3 recently. I have it charging all night and unplug in the morning to take it work, but upon unplugging I hear the fan come on, the screen is on and my tablet is warm to the touch. I look at the battery level and it's down to 77%! A 23% battery drain within an hour of getting to work from the time I unplug it! I did a full system virus scan and found nothing so what could be causing the issue?
 

Liam2349

Active Member
Good Afternoon all, something strange has been happening to my SP3 recently. I have it charging all night and unplug in the morning to take it work, but upon unplugging I hear the fan come on, the screen is on and my tablet is warm to the touch. I look at the battery level and it's down to 77%! A 23% battery drain within an hour of getting to work from the time I unplug it! I did a full system virus scan and found nothing so what could be causing the issue?

You shouldn't charge your device like that. It's bad to charge to 100%, ideally you should unplug it before, say at 90%.

I think you've probably messed up the calibration of your battery. Drain the device completely, until it shuts down, and then charge it once to 100%. This will hopefully fix your issue.
 

hughlle

Super Moderator
Staff member
I was under the impression that all modern devices were designed to have charging cutoffs so that its not always sat charging at 100%. Because who sets an alarm in the middle of the night so they can unplug it before it gets to 100%? Because overnight unmonitored charging is a pretty universal usage case.
 

Liam2349

Active Member
I was under the impression that all modern devices were designed to have charging cutoffs so that its not always sat charging at 100%. Because who sets an alarm in the middle of the night so they can unplug it before it gets to 100%? Because overnight unmonitored charging is a pretty universal usage case.

It's not ideal, Sony and another manufacturer bundled some software with their laptops to allow you to cut off charging at a certain point.

It's because you aren't supposed to store a battery at 100% charge.
 

hughlle

Super Moderator
Staff member
My point was rather that this is the way pretty much EVERYONE charges any mobile device, and it's never caused that much of an issue. I do not think that the OP's issue is anything to do with this. If it were so prone to creating this kind of issue then noone would be buying a dock or using this kind of device as a desktop replacement, which many people happily do and have done since the first laptop docking stations.
 
OP
CustomSurfaceP2
I appreciate the quick feedback, however I do not think that charging the unit to 100% and leaving it plugged in is the issue as my SP3 shows 100% charged when unplugged, but the fan kicks in like something is running in the background causing the battery to drain. When I check task manager the COMSurrogate is usually at 10-15% while WindowsExplorer is at 9% which is unusually high for nothing running besides antivirus and some apps that startup but sit idle. From what I know, charging to 100% is not a problem, but not letting it go down to 10% at least once a month would deteriorate the battery at a faster rate.
 

Bandito

Active Member
The charging issue is a moot point as all of the controls necessary for proper charging and battery maintenance are built into the hardware nowadays. It is true, however, that if you're getting inaccurate battery readings that a full discharge cycle will allow the system to recalibrate itself.

That being said, I don't think it is relevant to the OP's issue.

It would appear that while his SP3 is in transit, it is not going into sleep, hibernate, or power nap mode. This can be caused by numerous items, such as an application that is running which prevents sleep/hibernate, a faulty driver that also prevents sleep/hibernate, or even a device that keeps waking the system up. This could include, for example a Bluetooth mouse that is left on in your travel bag whose buttons get pressed occasionally during movement or the keyboard cover being pressed enough to enter a keystroke and wake the system up.

These latter two issues are easy to fix. The mouse can be turned off while in transit or it's ability to wake the computer, along with the keyboard's, can be disabled by going into Device Manager and selecting the device's properties and under the Power Management tab, unchecking the box for 'Allow this device to wake the computer.

Good luck in tracking down the cause of your SP3 not properly sleeping/hibernating/power napping.
 
OP
CustomSurfaceP2
Thanks Bandito, I hope I can find the issue, I am disabling my antivirus today because maybe there are overnight updates that are waking the device? I have no mouse connected and I know my pen button is not depressed since OneNote is not open when I open the keyboard cover. I leave the tablet on my passenger seat with the keyboard cover closed so i cannot imagine a key being pressed. It doesn't happen all the time, only recently since the last firmware update. Maybe it is faulty firmware.
 
OP
CustomSurfaceP2
So I found the issue, there was two problem programs causing high CPU usage. Avast Antivirus and RealPlayer Windows program. The Avast caused the highest CPU load. Once I disabled it it dropped the CPU down to 0-3% usage!
 

Liam2349

Active Member
I appreciate the quick feedback, however I do not think that charging the unit to 100% and leaving it plugged in is the issue as my SP3 shows 100% charged when unplugged, but the fan kicks in like something is running in the background causing the battery to drain. When I check task manager the COMSurrogate is usually at 10-15% while WindowsExplorer is at 9% which is unusually high for nothing running besides antivirus and some apps that startup but sit idle. From what I know, charging to 100% is not a problem, but not letting it go down to 10% at least once a month would deteriorate the battery at a faster rate.

No, you let the battery drain once a month to calibrate it, it has nothing to do with the battery deteriorating. Letting the battery sit at 100% charge is what deteriorates it, so I try not to do it with my Surface. I believed it to be well known that letting a device sit at 100% is bad for the battery, that's why you need to remove the battery in your laptop when you leave it plugged in.

My phone, however, I do let sit at 100% since the battery can be easily replaced, so I don't really care - but the Surface.... Non-replaceable.

I was suggesting that your battery required recalibration as allowing it to sit at 100% would also probably mean more frequent calibrations are required. Surface devices use good batteries so letting it sit at 100% won't kill it too quickly, but it will kill the battery faster than capping it at 90%, or 80%.. or any other figure. You just need to find a compromise between longevity and charge.

Since you've said the fan comes on, it's probably something different.
 

mtalinm

Active Member
Similar problem here. Had it in my bag charging overnight, found it in the morning with the fan whirring :-(. disabled keyboard-wake.

Then it dropped 30% while in my bag for 5 hours. Then I used it for an hour, leaving it at 50%. Just opened it up again several hours later and at 30%. Completely pathetic. My SP2 never did this.
 
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