2017 MacBook Pro 15, Battery with Home WiFi is Great, Public Wifi Battery is Awful

[upintheclouds]

What is going on with my MacBook Pro's battery? I have iStat installed and when I am at home doing light things like Safari, Mail, Notes, Calendar. Brightness is 75%. When I am at home I will get 10+ hours. When I am in public it tanks and I can get maybe 2 and half hours, maybe 3 and half. What is happening here? I do use a VPN. I've tested with the same server. I do the same thing on Safari at home and out.

 

[Sanpete]

You use the VPN at home too? (Maybe that's what you tested with the same server, hard to tell.)

 

[upintheclouds]

You use the VPN at home too? (Maybe that's what you tested with the same server, hard to tell.)

Yes, I have used the exact same server in public and at home to test this.

 

[Sanpete]

Do you tend to visit or keep a different webpage open away from home? Some use a lot more power than others. You can check in Activity Monitor.

 

[upintheclouds]

Do you tend to visit or keep a different webpage open away from home? Some use a lot more power than others. You can check in Activity Monitor.

For my testing I used the same websites and behavior. I will monitor Activity Monitor while I am out. I just thought though, could it just be the WiFi is just really poor?

 

[26139]

I usually have this problem with poor Wifi, as the signal in my home is super strong.

But keep testing, my difference isn't super noticeable.

 

[Sanpete]

Yeah, I wondered about poor wifi, but I've never heard of such a huge effect from something like that. There are ways to track the wifi strength and quality too, but I don't know much about it. You could try some online wifi speed tests just to be sure it looks normal.

 

[upintheclouds]

For those of you still following along, I think I found the culprit. It isn't WiFi at all.

I have used the same generic tabs in Safari during my testing, one of which is YouTube. I have been watching Activity Monitor. Its windowserver via Safari picture in picture. When I am using picture in picture, windowserver jumps to consume 25%+ of my CPU. When its turned off it dies down to about no more than 8%, most of the time between 0.5%-5%.