Cell standby battery issue - I think I may be on to something

[Garemlin]

Ok so apparently alot of us have an issue with cell standby draining our batteries. Well I was digging around my A500 today and discovered something pretty interesting. I don't actually have an A500. I have an A501. This is the version that is slated to go to AT&T and has the 3G radio.

-Go into your settings menu
-Click about tablet
-Click device information
-Fifth one down is your model ID

So I am guessing this may have something to do with why we are getting battery drain from cell standby.

 

[junkyde]

I have a A500

Modell-ID: A500
so what?
I really don't know what you mean

 

[Garemlin]

Mine is a Model ID A501. It is supposed to be an A500.

The A501 is the version of the A500 that is going to AT&T and will be on their 3G/4G network. Which means it has the 3G/4G radio. Which may explain the cell standby battery drain.

 

[dan776]

Good thought... mine is a 500 though and still has the issue. Something that isn't physically there can't drain the battery, so its probably just a misnamed process from the CPU... especially since airplane mode doesn't fix it.

 

[junkyde]

Okay, but that was kind of confusing because you wrote you have an A501
So still, my Model ID is right, but I also got that battery issue

 

[pentool]

As I posted on another thread:

I don't seem to have any battery drainage issue. Before I gone to bed, I put the tablet into Airplane mode and I wrote down my battery level: 45%. After I woke up after 6.5 hours, I looked at it. The battery level was still spot on 45%.

I could be wrong, but the reason you guys may experience this issue because of a setting. If you go into Settings > Wireless & networks > Wi-Fi settings > Wi-Fi disconnect policy. Make sure it is set to "When screen turns off".

This way when the device goes to sleep, the screen turns off, and so, Wi-Fi shuts off as well, hence no drainage.

 

[Garemlin]

pentool: This isn't a wifi issue. This is a battery drain caused by cell standby. This should not be an issue with a wifi only tablet.

 

[pentool]

Oh, I'm sorry. I misunderstood.

 

[Garemlin]

Oh, I'm sorry. I misunderstood.

No worries.

 

[dan776]

I don't know, though, if it really even matters that much.

I was playing with the tablet for a little over an hour, and the battery life went from 100% to 90%. 12% of this drop was Cell Standby, which basically means that Cell Standby accounts for about 1.2% of total battery loss per hour.

Then, I had my tablet with the screen off for over 2 hours. Checked the battery, and it was still at 90%, with 12% still being Cell Standby. (No change in distribution of battery loss). During the down-time, the unit was still syncing with GMail and E-Mail, as I heard the notifications and when I turned it on, saw the notifications.

If Cell Standby was really happening, it would continue to drain the battery at about 1.2% per hour. I should have seen a 2% drop at least over the 2 hours it was dim, but I didn't... Even though I continued getting notifications of email.

 

[dan776]

OK - Sorry for the double-post. I take back my last post though.

Picking up the tablet now after a couple hours of downtime, the battery life shot down from 90% to 87% after about 20 seconds of actually using it. (Before I just put the screen on for a quick check, and the battery info hadn't updated yet).

Now Cell Standby is up to 14%.

So this means, my last post is incorrect... I'm sorry for jumping the gun on that before really analyzing it completely.

Now I believe that about 1.2% per hour is eaten up by Cell Standby.

 

[rcmolski]

My model no is also showing as an a501. The other interesting thing I noticed was the SKU description....mine is listed as 3G.

There's tape over the SIM slot, but I don't think there's a reader behind it; I think I can see light from the display there.

Very interesting.

Bob

 

[dan776]

Confusing... Right in the root "About" page, I show having an a500. But then when I click on Device Info, it says a501 with 3G.

I wish there was a widget like "Dazzle!" on the Droid which let you just disable the cellular signal and 3G while keeping the Wi-fi going (great App by the way if you have a Droid X). I can't seem to find anything with that kind of control on the market for Tablet. Dazzle isn't even showing up in Market for some reason.

 

[Dart]

Cool! I have a A501 too.
Does this mean there is a 3g radio already built in? That would be double cool.

 

[Dart]

The tape comes off easily. Nothing appears to be behind it.