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Power Cover Charging Quirks

Sir Face

New Member
I have the new Power Cover and am learning to like it, even without the back-lit keys. One odd little thing that I am noticing though, is the fact, that if I attempt to recharge it (SP2 & Power Cover of course) before I have ran BOTH batteries almost completely down, the Power Cover battery doesn't want to take a full 100% charge for some reason. Is there some reason for this behavior or do I have a lemon here?
 
I don't own one, but from the reviews I've read:

When they are both depleted, the SP2 will charge to 80%, then the keyboard will begin to charge. When the keyboard hits 80% it will stop charging, and the SP2 will finish charging to 100%. Once the SP2 hits full charge, it will switch back to the keyboard and charge to 100%.

Microsoft Surface Power Cover review by GuruSushi - Engadget

[edited to link source]
 
Here is the sequence (from Microsoft Power Cover Reference:


Charging sequence
The Surface and Power Cover batteries are charged and discharged in a sequence designed to keep most of the charge on the Surface battery. Understanding the sequence makes it easier to predict how much charge to expect on each of the batteries.

Which battery gets charged first?
Once Surface is 80% charged, it starts charging the Power Cover. Then, when Power Cover is 80% charged, Surface finishes charging. When Surface is fully charged, Power Cover finishes charging. Surface and Power Cover will charge whether Surface is on or off, as long as Surface is connected to a power source and Power Cover is connected to Surface.

Which battery is used first?
When you’re using Surface and Power Cover and the Surface isn’t connected to a power source, Surface draws power from Power Cover first. When the charge on the Power Cover gets low, Surface switches to its own battery. If the battery on the Surface gets low, it switches back to drawing power from Power Cover.

Power Cover continues to charge your Surface while it is in sleep or on standby. If Surface is turned off and unplugged, or the Surface battery is completely drained, it can’t detect the Power Cover or draw power from it.

If the battery on the Power Cover is completely drained, you can still use it as a keyboard.

Battery discharging charging sequence
How charge is transferred from Power Cover to Surface.

How much charge do you have?

You can check your charge two ways:
•Check the battery icon on the Start screen for a weighted average of the two batteries.
•For detailed info on your battery levels, open the Desktop and tap or click the battery icon in the tray. This lists the charge on each battery.

Tap or click the battery icon in the desktop tray to see the charge on each battery.
 
Even with all this information, I still don't quite understand why, that if I run the Power Cover's battery down, say, half way or so, (while the SP2's internal battery still remains at 100%), turn the SP2 off (total shutdown) and attach the charger overnight, I still can't get the Power Cover's battery to fully pump back up to 100%? About 70% is the best it will do.
Maybe this is an issue that can/will be addressed with a firmware update, but now I've became afraid of Microsoft's ill-begotten updates that screw up so many other things. I'm just now getting my Hulu back up and running after the March update screwed up the video driver and made it unusable.
 
Here is the sequence (from Microsoft Power Cover Reference:


Charging sequence
The Surface and Power Cover batteries are charged and discharged in a sequence designed to keep most of the charge on the Surface battery. Understanding the sequence makes it easier to predict how much charge to expect on each of the batteries.

Which battery gets charged first?
Once Surface is 80% charged, it starts charging the Power Cover. Then, when Power Cover is 80% charged, Surface finishes charging. When Surface is fully charged, Power Cover finishes charging. Surface and Power Cover will charge whether Surface is on or off, as long as Surface is connected to a power source and Power Cover is connected to Surface.

Which battery is used first?
When you’re using Surface and Power Cover and the Surface isn’t connected to a power source, Surface draws power from Power Cover first. When the charge on the Power Cover gets low, Surface switches to its own battery. If the battery on the Surface gets low, it switches back to drawing power from Power Cover.

Power Cover continues to charge your Surface while it is in sleep or on standby. If Surface is turned off and unplugged, or the Surface battery is completely drained, it can’t detect the Power Cover or draw power from it.

If the battery on the Power Cover is completely drained, you can still use it as a keyboard.

Battery discharging charging sequence
How charge is transferred from Power Cover to Surface.

How much charge do you have?

You can check your charge two ways:
•Check the battery icon on the Start screen for a weighted average of the two batteries.
•For detailed info on your battery levels, open the Desktop and tap or click the battery icon in the tray. This lists the charge on each battery.

Tap or click the battery icon in the desktop tray to see the charge on each battery.


Microsoft is telling me (I hope erroneously) that the LED in the charger cable should ALWAYS be on, if it's attached to the Surface. Mine never does nor ever has, even before I got my Power Cover. The LED comes on when the cable is first attached, but goes off at a point (such as when left attached overnight). They say that I've either got a defective SP2 or a defective charger one. That's why they say my Power Cover's battery is failing to take a full "top-up" charge. Do you buy that?
 
Ya. Maybe. I think the cable light is on all the time on mine when plugged in to AC and connected to the Surface.
 
This light has always been a bit confusing... my charger connector light use to stay on all the time whenever attached to SP2 and AC, but at some point in the last couple months after what I can only assume is a result of an update, mine now does go off at some point after the SP2 is off and fully charged. I never saw that change noted in any of the update logs, so maybe it has always behaved this way, but I can confirm that at some point after fully charged the light goes out when powered off.

I just received my Battery Cover today, it is charging now. I will report back what it charges to (SP2 @100%, Power Cover arrived at 50%, charging now).

EDIT: Just checked, Power Cover is at 87% and still charging.
 
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Well, I seem to be having wonky charging issues as well with the Power Cover... I plugged up my SP2/Power Cover last night, SP2 was around 60% if I recall, Power Cover was 0%. Let charge for 10 hours while powered down. Woke up to find the SP2 at 100% and the Power Cover at 22% when I powered on the device. Power Cover does appear to be charging now (it's up to 28% 15 minutes after powering on SP2).

That pretty much defeats the purpose of the Power Cover if it won't reliably charge.

Curious sharpcolorado, you seem very satisfied, how is yours behaving?
 
...Curious sharpcolorado, you seem very satisfied, how is yours behaving?

I keep the SP2 on the Microsoft Docking Station, with the Power Cover attached. When I remove it for use, and check power, I get 100% on both devices. Total battery life typically shows 7 1/2 hours or so, and that is about what it really uses.

My use is typically on WiFi (5GHz), with Outlook running and refreshing every 5 minutes, lots of web browsing, some printing, and some graphic work.
 
Curious, when you have it in the dock, does your Power Cover charge when the SP2 is turned off? Apparently for some reason the Power Covers (some, all, no idea?) aren't charging when the Surface is turned off and plugged in... only when it is on or in sleep mode.

Mine charges right up to 100% when it is turned on, just won't charge when turned off. Seems there's a thread on it over on the MS boards as well with similar issues.
 
I had run the battery down on my power cover to about 20% . I attached the charger to charge it up overnight and left the computer running because I had read here that the battery might not charge up fully while shut down. Well, the power cover did not charge at all last night. I had to reboot this morning to get it to start charging. Obviously there are some quirks in the firmware to be worked out.
 
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