Surface Pro 3 not increasing charge when high CPU use (video editing, etc)?

[SimmZ]

Hi everyone,

Probably not a problem nor an issue, but I just noticed (after 10 month I got my Surface Pro 3) than when my Surface Pro 3 i5 is working on very high CPU (ripping video, etc), then the fan run on full throttle (normal behaviour), the battery are not increasing its charge... for example this morning I was ripping a HD video for about 40 minutes, when I started the ripping on my Surface 3 Pro, battery level was at 90% (in charge), but during the video ripping process, battery stayed at 90% (in charge) flat all long and doesn't increase. When I completed the video ripping and leave the Surface cool down a little bit, battery increase to 91%... 92%... etc until it reached 100%.

Have you noticed this behaviour? It's like if the charger doesn't deliver enough charging power to charge the battery when CPU and GPU are under heavy load, it's only maintaining the battery level, but not actually charging.

This is just because this is not a common behaviour on a laptop... because even under heavy CPU load, my laptop battery are increasing its charge, not only maintaining.

Thanks for sharing your experience ;-)

 

[razy60]

Might be because the charging power is being redirected to the high level function and any residual is used to maintain the battery level, in that way it would only use the minimum power required instead of charging the battery and then trying to keep it topped up, that way being more economical.
I heard that the new CPU's can sort of act this way with the correct PSU, on my desktop my system acts in a similar fashion, only ramps up the voltage when required.
Or I could totally barking up the wrong tree.

 

[Jason Cliche]

I noticed this too. Once I ran it to the dock to charge it and get charged for a meeting, so let it charge while doing some work on it and after an hour I expected a good change but only got a 1% increase in battery charge. I used BatteryMon to learn that the charge rate was about the same as the discharge rate when using it for moderate usage. If I need to change it up in a hurry I completely power down the computer, if possible.

 

[SimmZ]

Thank you folks for sharing your experience! That's what I thought... not something actually defective but more like a design flaw... honestly it's a little poor design to have to put the tablet in sleep (almost) to get an effective charging. As I told you it's a new behaviour in my IT career, because on my other computer, who's a MacBookPro Retina, no matter if I compress HD video or anything else with a very high CPU usage (i7 CPU), my laptop are charging at the exact same speed always, except maybe if I shut off the display where it will charge a little quicker! I also own a HP EliteBook laptop (i7 CPU too) with same result where CPU usage doesn't involve with charging time.

Thanks again!

 

[GreyFox7]

More likely the result of tradeoffs necessary for the form factor and managing thermals. Charging will generate heat, heavy usage will generate heat so cutting back the charging would be an optimization of power management in deference to user workload demand.

 

[Telstar1948]

I use my SP3 in the MS dock with two external monitors and a plethora of USB stuff hooked up too. I don't do heavy tasks such as graphics/video work on mine. I do more of the usual office stuff; however, my SP3 will charge back to 100% while I'm working with it in the dock.

 

[mtalinm]

my dock failed to charge SP3 yesterday while running it hard for hours on end. in fact I think the battery drained a bit during that time.