Why might one wifi network kill my battery...

[IIGood]

...and not others?

It seems that the wifi network at my office will put a bigger strain on my phone's battery than when I connect to any other wifi network. For the "other" networks, they're usually smaller scale networks like someone's home router, a store/restaurant's public wifi, etc. For the office network, it is a larger corporate-type of network with many WAPs located all around campus to allow for maximum signal strength and smoother transitioning from one place to another. The company recently instituted an all-wireless policy on campus mainly due to the cost benefits. It just would've been too costly to rip out all the old CAT3 cabling in the building and run new CAT6, so they decided to just beef up the wifi.

I have an S6 now and the battery drain doesn't seem as bad as it did with my previous device, a 2013 Moto X. Typically, my day goes like this...the phone comes off the charger at home around 6 am, I'm at work by 7. My usage at work is minimal...might check calendar appointments, maybe send a text or two, and maybe a phone call on it a couple times a week.

With the S6, if I put it on wifi, the battery gets down to 80% by about 10 am. Not horrible, but if I just use Verizon's 4G, I'll be down to 80% by mid-afternoon.

When I had the Moto X, given the same circumstances, the phone was down to 60% battery by 8 am. That was insane. But if it was on 4G, I would still have about 70% battery by the time I left the office at 5 pm.

When I get home, I put the wifi back on because cell signal is terrible at my house. And as previously stated, my home wifi does not excessively drain the battery to the extent the corporate wifi does.

I first noticed the excessive battery drain on the Moto X after it was upgraded to Lollipop. With KitKat it was much better. And since the S6 came stock with Lollipop, it's had that wifi drain out of the box and upgrading to Marshmallow hasn't helped.

So I'm wondering why just the corporate network is putting that strain on the battery. Is it the number of WAPs within such close proximity? In the ~1500 square foot area I sit in, I can see 3 WAPs.

Thanks,

 

[Jonny Kansas]

That does seem rather odd. I'd like to see your battery usage screen from different scenarios/parts of the day.

How do you know that it's the wifi that's putting the drain on the battery? Just because you seem to lose battery faster when on the work network? Not trying to second guess you, just want to make sure we get as much detail as possible. I would think that the signal should be very strong by the sounds of it, so unless you're doing more over the network and/or the phone is doing more in the background over that particular network, I'd think it should be softer on the battery than if you were connected to a network with a poor signal, as that might cause it to lose the connection and poll for networks repeatedly, which should theoretically drain the battery much faster than just staying connected to a strong signal.

I wouldn't think bouncing from one AP to another all day should have that much of an impact. AFAIK, the phone should see all of that as one single network. Perhaps it does do some polling to decide which AP has the best signal as you move, but I still can't see it being a HUGE battery suck.

 

[IIGood]

That does seem rather odd. I'd like to see your battery usage screen from different scenarios/parts of the day.

It does...certainly in my mind anyway. I'll see if I can remember to get some screen grabs maybe next week; today and tomorrow may end up not being the greatest times to try again, but things should be a little more stable for me schedule-wise next week to test this out again.

How do you know that it's the wifi that's putting the drain on the battery? Just because you seem to lose battery faster when on the work network? Not trying to second guess you, just want to make sure we get as much detail as possible.

No, I completely understand. But I guess I don't know for 100% absolute certain it's the wifi...it just strongly seems like that's the factor in my mind. Once I'd switch wifi off, the battery would stabilize more...so unless there was some weird background process going on "invisibly" while connected to the wifi, I can't really think of what else it might be. I never saw any unusual processes running away with battery usage, it just seemed to be wifi sucking it down...everything else like the OS and Standby and other general services all seemed to be within their normal usage range.

I can say that it was very consistent for me when I was using the Moto X. After the L update, I started seeing this, then once I "figured it out" I started shutting wifi off when I got to work in the morning, then things seemed better.

I've only tried connecting to the wifi a few times since getting the S6 back in December, initially thinking I'd get similar results, and what I first found out seemed to be inline with that thinking. So I honestly really haven't been on the work wifi nearly as much as I was with the Moto X.

I would think that the signal should be very strong by the sounds of it, so unless you're doing more over the network and/or the phone is doing more in the background over that particular network, I'd think it should be softer on the battery than if you were connected to a network with a poor signal, as that might cause it to lose the connection and poll for networks repeatedly, which should theoretically drain the battery much faster than just staying connected to a strong signal.

I wouldn't think bouncing from one AP to another all day should have that much of an impact. AFAIK, the phone should see all of that as one single network. Perhaps it does do some polling to decide which AP has the best signal as you move, but I still can't see it being a HUGE battery suck.

This is all my thinking as well. I certainly wouldn't think moving between APs would have any kind of impact, or even the number of them in an area.

I even asked one of our network engineers about it once and he couldn't think of any reason why that might be.

 

[cr6]

Are your apps in the play store set up to only update on Wi-Fi? If so, you might try disabling that setting for a few days and see how you fare.

S5 tap'n

 

[IIGood]

Are your apps in the play store set up to only update on Wi-Fi? If so, you might try disabling that setting for a few days and see how you fare.

Not a bad thought. That option is enabled so I could give it a whirl. Right now the updates only seem to push at some point overnight. When I wake up in the morning, I've got the notification that apps were updated...can't say I've ever really noticed it at any other point throughout the day.

 

[Mustang02]

Does your work wifi have a firewall behind it? Your phone is checking for emails or trying to update apps that are blocked sites.?


At my work I can't get email, Facebook, etc so I'd be eating battery power trying to sync.

 

[IIGood]

Does your work wifi have a firewall behind it? Your phone is checking for emails or trying to update apps that are blocked sites.?

At my work I can't get email, Facebook, etc so I'd be eating battery power trying to sync.

Didn't think of that either. Good point.

There is a firewall, but it's pretty open. About the only things I can think of that they block are the "adult" content and the major video streaming services like Netflix and Hulu. YouTube is allowed.

I have Facebook disabled on the phone since I don't use that, but it can pass the firewall. I'm pretty sure the Play Store is allowed through too since I've accessed that while on the corporate network. But I do have Netflix on the phone...hm...could the app on the phone be trying to poll out somewhere even if it's not open?

 

[IIGood]

Well. It seems my phone is now mocking me, thumbing it's nose at me and saying "Nyah-nyah nyah-nyah nyah nyaaaaah..."

My morning freed up today so I've been able to run a test. I've had it on the corporate wifi since arriving at 7 am, it's now just after 9 and my S6 is only down to 97% battery without any major usage. I did leave the "app update over wifi" turned on for this run and the only activity I had on the phone was receipt of a text message which I did look at. Oh, and taking this screenshot of course. Other than that, no usage to speak of which essentially falls in line with my normal routine.

So clearly I'm now thinking there's a service that might be running away with the battery. I have noticed sometimes that Google Services tends to chew away at the battery, quite heavily, but only about once every few days. A reboot will typically clear that up. Maybe that's what I had seen before - at least on the S6.

 

[IIGood]

I'm approaching the 5-hour mark with the phone being on the corporate network and it's down to 90%. See this screenshot. Only the 3 processes are there - Android OS, Phone Idle, and Cell Standby. I've not used it since the previous post but I am about to step out for lunch...though I probably still won't actually "use" the phone. It'll just jump off the wifi and go to 4G for a bit until I get back in the office.

 

[mountainbikermark]

Try turning auto update off for the Play Store. If it is seen as being on an open network it'll keep looking for a secure one as Play Services chews away at your battery. If there are no updates trying to update it won't seek a secure connection, thus not use battery.

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[IIGood]

Eight hours in and the phone is at 80% battery. There wasn't any extra drain when I left at lunchtime...after I returned to the office I did end up making a brief phone call on it at one point, wasn't quite 5 minutes long. This all seems more in line to what I'm used to so if this continues, I may just resume getting on the corporate wifi daily (and it would keep me from having to remember to turn it off every morning, then back on in the evening...LOL).

When I just looked now at the services, I did once again see Google Services appear on the list. It was "only" at 20% usage but I'd bet it could creep up. I took the suggestion of killing the app auto-updater so I'll see if that could help keep Google Services in check. Almost wish there was a third option for auto updating which included updating only on wifi while charging, which would also only allow it to poll out at that point.