Understanding Battery Life...


Nov 6, 2009
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Something people need to understand a little with battery life and those nags people get about phones.

First off - Out of the Box Battery Life - I am sure many of you remember that the rep and even some manuals say you should 'charge your battery for 24 hours before using'. This is roughly 'conditioning the battery'. By Law, devices are not suppose to be shipped with the battery installed. And more to the point, the battery is not to be at 'full charge'. The reason for the message of needing to charge the battery for 24 hours is to insure it has a good standing charge and to get the most out of the battery as much as possible.

What most people don't do, and I am also one who has done it with my own droid, is assume that we have a good battery and just use it. Problem is, most batteries do not function in a 'linear' way. Linear meaning, I go 5 steps, it is 5 steps down, I go another 5 steps, it is another 5 steps down.

Most batteries function in a logrhytmic way. Logrhythmic, meaning that I go 5 steps, it will go down 2, I go another 5 steps, it may go down 3, another 5, it may go down to 3.5. It isn't steady or 'straightforward'.

Standby/Talk time - People wonder why there are two different times, and yes, I know many of you know standby means phone isn't being used, and Talk is when it is. What people don't understand is why the battery can't maintain both at the time.

Standby is longer due to the fact that you are not broadcasting. Broadcasting a signal, even with towers trying to receive signals, still takes a reasonable amount of power for a device of its size. The power to just 'listen' for a "Hey, you got a call/text" is minute mostly because you just need to receive a signal and process it. But when talking or making a call, you are not only receiving and processing the signal, but also trying to send out a message back out and hoping another tower will receive and process it. If these were the old Analog phones, the ones with the big battery packs and huge antennas, you would be using a lot more power to do the same thing.

Apps - As many people here have stated, you really don't need to go Kill App crazy, however, you do need to understand something with regards to some apps.

Any app that needs to use the network, will cause a slight drain in the battery. Why? Well, let's explain something about how the internet works.

Network Apps need to 'talk' to something. They send data to a server saying, "Hey, give me data for this..." So now, you are spending a little 'talk time' because your phone is sending a signal out due to that app.

Things like Streaming Music, IM, or even that little weather update app you have running. They will go "Hey, I need more info, send it to me." So you are burning battery power because these chatty programs are sending data out to get more data in.

This is the reason why one of the battery conservation suggestions from the droid booklet says to not have background data or sync on all the time. While Gmail can push its mail, the pop/imap stuff will require you to setup a time interval so you can get your mail, but generally, you want it at a longer time interval to avoid constant 'chatter'.

And just so you know, IM is one of those constant chatter apps because it does ping the IM Server with the "I'm online" status. Most IM programs don't have a convenient 'sync' timer to do that, as IM servers and clients like to keep 'up to date' on status for that reason.

This is not to say you need to go crazy or OCD on killing tasks, just be aware that if you want to prolong your battery life, make sure you minimize the number of network talking apps as much as possible. The fewer there are, the less 'talk time' is used on the battery charge.
What kind of battery life are you getting? Just replaced my droid with a new one because I didnt feel it held the charge. Within the first hour of being unplugged i lost 10-20% without doing anything and also not running any apps. Now I am not using an app killer with the new phone and will see how it plays out. I just want to be able to get through the day without having to charge.
Also, is there a condition cycle for the battery and how is it done properly?
Also, is there a condition cycle for the battery and how is it done properly?

The general recommendation for conditioning is to charge your phone a full 24 hours.

For instance:

[FONT=Verdana, Arial, Tahoma]How to Maximize the life of your battery.There are several things you can do to maximize the useful life of your battery. Batteries typically have 300 to 400 charge cycles in their life span.
Dirty battery contacts are the number one source of charging problems. Clean the battery contacts with either an eraser or use alcohol and a cotton swab from time to time. Make sure no eraser or cotton is left on the contact points.
Don’t leave your rechargeable batteries dormant for extended periods. Cycle them for a full charge & full discharge every so often, preferably monthly. Whether you use AC or DC power to charge your battery most of the time, try to drain the battery periodically to keep it fresh and healthy.
Unplug your battery charger if you are not using your cell-phone. Batteries that sit idle for extended periods of time without charging, begin to lose their ability to hold a charge, and will self-discharge, so remember to charge them again before use.
Always store batteries in a cool, dry place away from heat and metal objects.
Always allow a battery to warm to room temperature PRIOR to charging. The temperature shock can kill a battery chemically as well as potentially causing a short circuit.

Temperature effects -- All batteries should be charged up between 59 degrees & 77 degrees Fahrenheit. Permanent damage to the cells can occur if the battery is not warmed up before attaching any battery charger. Your cell phone's battery also works best in a comfortable temperature! Try to keep it between 59 and 77 degrees Fahrenheit. Cold batteries may temporarily fail to deliver any energy to your cell phone, despite being fully charged.

[SIZE=+1]Initial Charge Cycle
-- Turn the cell-phone OFF. New batteries must be rapid charged (typically to 80%), then trickle charged (slow charged to 100%) for 24 hours, prior to their first use and for the first 2-3 cycles. As all of our batteries are new, they are uncharged when you receive them. All batteries require a "break-in" period, so don't be alarmed if your battery doesn't hold a full charge right away. A new battery commonly will show false full charge (voltage), or "Not charging" as indicated on your cell phone or charger. LEAVE it on the charger for 24 hours! Also the battery may not immediately power up the phone because of low voltage.

For the First Three Cycles, please make sure to charge the battery fully (24 hours) WITH THE CELL-PHONE TURNED OFF, and drain it fully (by using it until it will not power up) before recharging.
This will properly condition the battery and will ensure that it will operate at its maximum capacity.
This is recommended for all cell-phone batteries.
You can discharge most portable cell-phones by unplugging the battery charger and leaving it turned on until completely discharged.
For NiCad (Nickel Cadmium) batteries: A slow charger works best on Nickel Cadmium batteries.
For all other batteries (Nimh, Li-Ion, Li-Polymer): A rapid charger works best, even though it should charge for 24 hours initially to allow a full 100% battery charge.
For vibrating batteries: Note that the battery does not vibrate when the phone is connected to or placed in any charging device.
This came from one site. Of course, many of us don't bother doing this correctly, so I stick with the general rule of thumb of having it charge for a full 24 hours so the battery has a good charge for it to calibrate itself.

As for how long do you go between charges, it varies as it depends on what you have running on your phone. Remember as mentioned above, it is a matter of how much 'chatter' your phone will do. This is also a known problem with many other smart phones, like Blackberry and iPhone. The more little apps you have running out into the network, the more talk time you actually burn on your phone A good rule of thumb for conservation is just kill apps you know are slated for network use that you don't need. I know that Calendar, gmail and mail will always need to be up because they are setup for syncing. But stuff like Pandora, or Meebo or Talk does not need to be on unless I want it to be on, and in all honesty, you should make sure programs like that shouldn't be left 'on' unless you need to, which will help extend your usage.

The longer you want to keep the battery up, regardless of it being a Droid, iPhone or Blackberry, is tied to what you leave on. If you don't have bluetooth on all the time, turn it off on the phone. That also 'pings' to see if there is a bluetooth device.

Any application that has to drive something will also burn some battery time. Music, for instance, will do some obvious additional burn on the battery as it requires power to drive the audio to your headphones or to the phone speakers. This is not to say you shouldn't listen to music, just be conscious of the fact that part of it will also burn some juice as well.
I've read this same stuff on many electronics. I don't think anyone with a new gadget they are excited about is going to charge it up for 24 hours without using it, and do it 3 more times. That's like giving a kid an ice cream cone and telling him to hold it in the freezer all day, don't lick it.. then pull it out so it melts a little..then put it back in there all night.. etc. Nobody is going to just sit by waiting patiently for 3 to 4 days while their battery conditions.

I usually do the drain till it goes off, charge it fully for a few hours, and so forth. But that is usually with ni-cad batteries. I read somewhere this is a Li-ion, which I understand has no memory issues and you can charge it whenever, part way, fully, etc supposedly.

BTW, Locale seems like a kewl app to "save" the battery when you get to certain locations. However, keep in mind that services are background apps with no interface (although apps may have interfaces that interact with services) that can and will run while your phone is off. That is how messages still beep you, alarm clock goes off, etc. Those all will drain your battery a little bit. It's best before you close your phone to make sure you aren't running any background apps.

Funny, when I think about how cool this phone is, I can't help to think some people are not going to realize that they literally have a computer that 7 years ago was a really good home computer, in their pockets. As such, there is a little bit of "care" that Android device users have to learn. No longer is it just a phone, it runs software like your home computer. I think this may be another "selling point" for iPhone unless they switch to allow multiple apps run. With only a single app and no background services other than their own apps that you can't access/control, they may be much more appealing to those that want a powerful smart phone but don't need to worry about the little things, like shutting down apps that can drain the power while the phone is off. Most consumers wouldn't know how to do this, or if they heard about it would be put off and not want to deal with it. Thank God kids/teens these days or so technically savvy.. they will be the future adults that in mass will be used to this sort of tech. We are still in a transition stage where most adults can barely use a computer, so this type of phone may be too much for them. It is very neat to see tho.. watching the world evolve around us. Can any of you imagine taking this phone back 10 years, 20 years ago.. They'd think we were the real Star Trek crew.
Some battery life comments....

I work in electronics with batteries myself, so I figured I'd add a few comments.

Most companies do suggest you charge for 24 hours on start. Part of that's the fact that Li-ion cells (unlike NiMh or NiCAD) have a fairly complex charging cycle... they like constant voltage during part of the charging cycle, then constant current. You don't worry too much, since the charging circuit itself is on your phone... but they want to ensure you get a proper charge.

In the box, the cell could have bleeded power. Li-ion cells have a pretty low self-discharge rate, but when they drop too low, bad news... that can actually damage the cell. Really smart chargers know how to "reform" the cell, but that takes awhile. So they're just being very careful here.

On standby vs. talk... any time your phone needs to talk to the cell tower, it's putting out a power level that can reach up to 1 Watt of power. To receive a signal, you're talking a couple of milli-watts.. same reason you can run a Walkman-style radio off a couple of AA cells for many days. When you're in standby mode, the phone has to sync with the nearest cell tower, and may occasionally ping it from time to time, but this is very low duty cycle. In talk mode, any time you're talking, you are using the maximum power consumption possible on the phone.

App killing.. maybe a good idea, depending on the app. An app in the "background", not doing anything, will not consume any measurable amount of power. But not every app that's not up-front will not use power (or, applying DeMorgan's theorem, apps in the background can still suck power). Those on the network, sure, but any use of hardware can be a problem. I left one of those "GPS Status" apps in the background, and it was not written to go to sleep when not "on top"... it sucked down enough power to make the DROID warm, and kill the battery. Apple's big claim about not supporting application-level multitasking is "battery life". While suspect some of that isn't the reason (eg, they want Apple-provided apps to be in a different capabilities class than 3rd Party apps... in Android, anything Google can do, you can do, app-wise), they do have a point. Multitasking is a great tool, but so is a scalpel... great for a surgeon, but don't hand one to a fool. My point... watch your power hungry apps, and if you discover one, kill it, erase it, or get an app manager that will kill it for you once it's pushed to the background.

Another battery thing -- battery life, long-term. One of my big problems with the iPhone (and there were many) was the fact that, if you're a heavy-duty smartphone user, you probably recharge every night, and may often run out of juice before the end of the day. The iPhone had a cell that will give you 300-500 full recharges before it's dying fast and needs to be replaced. Which is big bucks, since you can't do this, only Apple. Most Li-ion technologies also fail over time, no matter how many cycles the go through, but that's more of a 3-4 year thing. Failing on the phone contract, though, that hurts.

But hey, Hybrid cars don't have this problem. I have a 2003 Prius with 120,000 miles on it... the battery gets charged and discharged every time I drive, how come it's still good? Well, it's NiMh, but more specifically, the battery never gets fully charged or discharged. In that year, they only run it past 40% of it's capacity... stop charging at 80%, don't use the battery past 40%, and it lasts really long. This seems to be true of Li-ion too.

So, unlike NiCAD, there's no memory effect. But better still, if you charge regularly, before the battery dies, it's likely to last longer than those 300-500 cycles, which are based on full cycling the battery. This is the reason the iPod folks are not up in arms about failing batteries... most people will charge every night, but most batteries will probably be at 30-50%, not 1%.
Good info Hazydave! Thank God we can replace our batteries. I am amazed with any phone or device that does not offer a replaceable battery. Worse, the costs of said batteries are so expensive! The Droid battery I think is like $35 or something, and there is an extended one in the works I hear. This is not too bad if you ask me.

As for the apps that run in the background issue.. I may have said this on a different thread..but you are absolutely right..and to me is the ONE thing that will be difficult for normal users to understand. They'll download apps cause they look kewl, and not realize those apps install background services that may run and drain their batteries. I have a feeling that while Android is going to take off, this is the single biggest issue Android faces!! Anyone that does NOT understand how the whole background service thing works is in for a surprise when their battery dies in a few hours! I would bet if apple brings any sort of multi-tasking to its platform it will be only the top app running with being able to switch to other apps when they come to the top. Hence, you wont need to restart it from scratch. The Android supports this now.. all apps that run are essentially paused while the top facing app is running. Unlike most OSs where the top window is task switched with all the other apps/windows below it, on Android this is not the case. It pauses the other apps..they are not completely shut down..so they can maintain their state while the top running app is executing. But.. only one app is running. Now..that said, the background services are ALSO running behind the scenes, like the sms text messaging app, gps, etc. The cool thing is, which is why the whole app killer thing is not totally necessary, is that android will kill any app that is in a paused or stopped state if needed to allow for more resources for any of the services OR the top running app. Like I said, I would bet if apple does anything, it would do the top app multi-tasking so that you can at least start multiple apps, but only the top app runs, the other apps pause until you switch back to them. For a phone device with limited cpu/memory, this makes sense to me. The only way I could see this getting better, and I hope Android brings this into play, is the ability to "swap" memory to the SD card. That would allow a more realistic windows/linux/OSX like OS running on the phone. Still, SD cards are slow at writing too.. so I don't think this would be too good right now because the performance may take a hit when Android was going to write to the SD card to swap memory so another app can execute more smoothly. I doubt this will ever come to fruition tho.
if i didnt do that 24 hour charge thing, is my battery shot now?
How can you charge the batter for 24 hours? When the Droid is fully charged the charging light goes out. Will it sill charge when the light is out?
There are a lot of misconceptions when it comes to batteries and extending their life, and a lot of it is hold overs for the old nicad days. I am not going to sit here and explain it all,but heres a link to a very informative site

Welcome to Battery University

Lithium Ion batteries in today's phones are very durable and dont require the care the old nicads do, if you didnt charge it for 24 hours you will be fine, I am one of those people who are much to impatient for that and I always get full expected battery life or longer (I have a 4 year old razor that lasts nearly as long as it did when it was new, and a 2 year old voyager that still gives excellent battery life)

One major difference I feel I should point out between nicads and lithium batteries( in case most of you dont feel like reading the site) is that while on older nicad batteries it was reccomended, and you really should have, completely drained the battery before charging them because they developed a "memory" and if you did constant partial charges you would recieve less and less battery life because of this "memory". However the exact opposite is true of lithium batteries, it is best to do constant partial charges and to keep the battery above 40% if at all possible as full and complete discharges of lithium ion batteries can actually shorten there life.

Hope that made sense, I been drinking a bit HAH.


P.P.S. the site is very useful I suggest you read it if you are a geek like me or want to better understand battery life
As Retribution pointed, out Lithium Ion Batteries aren't as crappy as NiCad Batteries. Just cause you used it without doing the initial conditioning charge does not mean the battery is no longer good.

Not only from the site he has linked by where I got the information I quoted, the intent of the conditioning charge is meant more for getting the battery a proper reading of how much of a charge it will have. The three initial cycles just helps get a better gauge overall. The real drawback with Lithium Ion is that you can't really do a full discharge too much with it, in fact, LIons prefer to be recharged before you get to the complete discharge level.
Short Battery Life

I am sure I must be doing something wrong....but
Yesterday I went through 2 battery's in only 1/2 day with maybe 40 mins of talk time.
I ONLY had the bluetooth turned on.
Is this normal ?

ps .how do I kill gps app when I am not using it ?
I am sure I must be doing something wrong....but
Yesterday I went through 2 battery's in only 1/2 day with maybe 40 mins of talk time.
I ONLY had the bluetooth turned on.
Is this normal ?

ps .how do I kill gps app when I am not using it ?
You definitely have something going on there.

Good luck