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On AC power, does SP periodically intentionally let battery charge down?


Active Member
I use my Surface Pro 2017 mainly as a desktop replacement with Surface Dock and external keyboard/mouse/monitors/etc, so 95% of the time it's on AC power. A couple times (like right now) I notice the battery icon on the Taskbar not showing fully charged. In fact, it shows "xx% available (plugged in, not charging)".

Whenever I've seen the charge get to 10% or so, I've always disconnected and reconnected the dock (charging) and when it's reattached then the battery will show "charging."

Is that a normal process and W.A.D.? i.e. When the battery drops to a certain level will it automatically resume charging? A previous Lenovo notebook had a manual feature to deep cycle the battery: it would charge to 100%, then drop to almost 0% and then recharge to 100%. Is that what my SP is doing, or is something amiss?

The Lenovo also had a setting which was recommended when using the notebook on AC power: it would only charge to 60% which was apparently better than holding and maintaining a constant 100% charge.


Active Member
Alrighty, then. To continue my monolog:

I kept watching the battery life shrink until I got a pop-up advising of a low battery and suggesting I connect to external power. That was my first clue that there would be no auto-resume of charging. The battery level was 6%.

Shortly thereafter the machine not-so-graciously simply shut down. My guess would be 5%.

I detached the dock connector and re-attached in the hope that charging would resume. I noticed that the white LED was blinking slowly. I waited about five minutes and hoped that the battery had charged enough to reboot the computer. Nope. After 30 minutes (with LED blinking), still not enough charge to boot.

Left the dock detached for 30 minutes, hoping something would reset on the computer. Nope.

Then left the dock detached from both computer and AC power for 45 minutes. Nope.

Then I reattached the standard charging cord that came with the computer and voila! instant charging. Within a couple minutes I was able to boot.

So, the issue is with the dock.

However, a couple weeks ago I saw a "Surface Dock Updater" on the MS web site, downloaded and installed it. It detected an update available and installed it. I suspect that's the culprit.

So, I'm going to segue to a new thread with a title that hopefully will attract the appropriate attention: How to undo/revert a Microsoft Dock update?


New Member
For another reason I wanted to roll back a firmware update from last fall but was told I could not by Microsoft support. I have not seen your issue with my Dock. If this happened to me I would measure the AC Voltage at my receptacle to see if it was low. I have had AC levels drop to 95VAC or lower and various device became intermittent or would not power up.