• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

Using battery when turned off

Da_Coynul

Newbie
Nov 7, 2009
25
0
My Droid showed 100% battery charge last night when I powered it off. When I turned it on this morning it showed 70%. What gives? Is this phone running all the time, even when it appears to be powered off?

Update: I recently learned that applications running on Android can implement what is called a "partial wakelock" which prevents the CPU from going to sleep. Apparently it was discovered earlier that the built-in messaging app on the Sprint HTC Hero did this, resulting in a battery drain issue. With this in mind, I decided to do a factory reset (removing all apps and system settings). Then I repeated my overnight, power off battery drain test with no third party apps installed. Sure enough, after 8 hours I was still at 100% charge. I have not yet reinstalled any apps so I can't identify the culprit :(

Anyway, I am glad I was patient and did not try to exchange the phone since this could easily happen again with another poorly written app :cool:
 
I'd expect it to use something- after all that's a soft button and not a physical switch to disconnect power. So some part of the computer in the device is always on waiting around for you to turn the device "on" by pressing the button. But 30% overnight sounds like a TON. Hopefully that's not the norm.
 
Upvote 0
It would be really helpful if we could get some more people to try powering off at 100% charge at night, check their remaining charge in the morning and post the results (time powered off + remaining charge) here for comparison.

Mine was powered off for about 8 hours leaving me with the 70% charge as I indicated earlier.
 
Upvote 0
i charged mine to 100 percent last night then disconnected from power and i leave my phone on cause i use the alarm and this morning i believe it was 90 percent and that was with it being on all night

Just to be clear, I am not worried about battery drain with the phone powered on. Battery life with the phone running is really good and I have no problem with that. What I want to know is why the battery is draining when the phone is supposedly powered off completely and disconnected from USB.
 
Upvote 0
With the Droid fully charged, I ran Advanced Task Killer and then used the above method of turning the power off. (hold down power button and choose Power Off from the menu) Then I un-plugged the charger and went to bed.

6 hours later I turned on the phone and it was still 100% charged.

(I don't think the Task Killer was necessary)
 
Upvote 0
This is just a guess as I have already deduced that my Droid has problems, so I can't really help you guys test, but it might just be the battery, trying estimate how much power it uses up. During the boot sequence I'm sir it uses a ton of power, and maybe the phone is giving its seventy percent power left estimate assuming that its going to keep up that level of power usage. Have any of you guys tried just waiting ten minutes after turning your phone on to see if that estimate changes in awhile?
 
Upvote 0
There have been reports of the messaging app still being on and active even though the phone is turned off (on some models). I think this is a general problem, and needs to be resolved by google.

I do believe a process was running with the phone turned off. Here's why: I tested again last night after killing my weather and clock widgets (along with the clock widget updater). After 7 hours my battery was still at 100%. I am thinking about filing a bug report here: http://code.google.com/p/android/issues/entry but I would like to check into this a little more first.

JackTheMan - can you post a link to those reports you mentioned?
 
Upvote 0
1. Off doesn't mean, no power. Batteries that sit out don't drain, but batteries left in a device that's off DO drain. "Off" no longer means "off", it's more like "deep sleep" or "standby". As long as the battery is connected, there is current flowing.

2. Computers, and devices with computer-like functions have a clock that always runs, even if the computer is off. This prevents you from having to set the clock when you turn the device on. Smartphones may have this, or something similar.

3. It's possible the phone needs certain functions to run, or at least have power to them while it's off to decrease boot time.

4. Your phone many not have actually been at 100%. Charge your phone to 100%, then leave it plugged in for 4 hours after that to make sure it's actually at 100%. This isn't like the old school battery "memory" issues. This has to do with how the battery meter is calibrated. Your calibration may be off. Often, my phone might be at, say 50%. I turn it off, and then turn in back on 30-minutes to 2 hours later and it's at 62% --- somehow gaining battery back while being off.


I've had some similar issues with my G1. One time I left it charging overnight and it was still at 99% when I got up. I unplugged it, plugged it back in a few minutes later and within a few minutes it was finally at 100%. This has only happened once. I'd be more disturbed by a trend than by singular incidents.
 
Upvote 0
1. Off doesn't mean, no power. Batteries that sit out don't drain, but batteries left in a device that's off DO drain. "Off" no longer means "off", it's more like "deep sleep" or "standby". As long as the battery is connected, there is current flowing.

I agree but there has to be something wrong when your charge drops 30-40% overnight. If that's normal, what's the point of powering off at all? This morning mine was down to 60%. It has been charging for 20 minutes and is now at 70% so I don't think it's a calibration issue. Anyway, I don't see many people posting about this so who knows, maybe it's just my phone :(
 
Upvote 0
I think that this is somewhat normal for modern smartphones.

Case in point, I got the Droid Friday. Had my BB Storm on half the day till I was live on the Droid. That half the day I was hooked up to my PC so I was fully charged. The one hour travel/activation period wouldn't have taken much battery from the Storm. I shut it down when I was live on the Droid. Went to power it up today to clean it for selling, and it was ENTIRELY dead (with the Storm you can't even turn it on until it has 20% charge even when plugged in). It of course had the power sucked more quickly since it wasn't active on the network and was thereby in 1X mode. But the phone WAS "powered off" that entire time.
 
Upvote 0

BEST TECH IN 2023

We've been tracking upcoming products and ranking the best tech since 2007. Thanks for trusting our opinion: we get rewarded through affiliate links that earn us a commission and we invite you to learn more about us.

Smartphones