Cell Phone Battery Life

I'm curious. of course we all have moments when our fancy cell phones chirp 'LOW BATTERY' and subsequently 'RECHARGE BATTERY' and having it then shut down. but i'm not convinced it's really that low and it's turning itself off early for some reason.

Reason 1: the phone is turned on, then chirps 'RECHARGE BATTERY', and performs its shutdown routine. well, it sure has enough juice to do the dinky little AT&T Wireless animation and have the backlight lit shortly after before going blank! there's apparently more power for that alone!

Reason 2: on laptops, when Windows starts shutting itself down due to low battery power, it sure has enough juice to still do all the Windows Vista logoff sounds, video animation, and shows it up to 3 more minutes. and it said the battery is 'critical?' i highly doubt it!

Reason 3. Boot up an iPhone or iPod touch from a low-battery condition (as in a hard reboot) and it goes through all the booting routines long enough to show the home screen but then alerts the battery is too low to continue, but of course it still even then has enough to go through all the logoff routines?!

Is there still some life left and some reason it's just shutting down early? i don't know. but it does apparently have enough life left to show all that jazz as it goes off! i don't know why though.


Moderator, , , Webmaster of: Rabbit Ears
Staff member
It shuts down before the battery's completely dead so as to be able to save settings and shut down without corrupting something.

- Trip
Is there a way to disable that? on my Nokia 3595 (old GSM phone) it does that and i know i could get more life than it says. it's extremely annoying to have it say there's no battery left yet it goes through all those 'AT&T wireless' junk as it powers off.

I can see the possibility of corrupt files on an iPhone or laptop though. just not on an older cell phone. in my opinion though all that animation in the latter two cases if the battery's dead it should just say so and go right off. those animations waste power assuming the battery has any kind of wear.

I was able to turn all that off on my Acer Aspire One as it was doing that when i know i had at least half an hour remaining (just not according to windows) i like to run them down as far as they'll go if i'm relying on them for power. i want maximum run-time when an outlet is not available.


, Blogger: Orry's Orations
I've never heard of any way of stopping that. Like Trip said, it's a safety feature for settings. I'm not sure why anyone would want to risk losing your information for the sake of a few minutes of time. That's a risk I wouldn't want to take.
Shaving off those few minutes seeing all those visual themes would allow those same few minutes to do something else first. then some sort of basic shutdown. but then i'm talking rewriting windows for that.


Moderator, , , Webmaster of: Rabbit Ears
Staff member
You say that as though the system is wasting time showing an animation on shutdown. When Windows is starting up on your computer and it shows the logo with the little bar scrolling by at the bottom, the system is loading, not wasting your time. Similar situation when the phone is shutting off.

- Trip
i meant that even though it claims the battery is too low to continue, it still has enough juice left to play a melody, show the AT&T Wireless animation, an animated 'goodbye' so it's not really dead is it?

on my computer, it still has enough left to play the logoff noise ans then sit at 'Windows is shutting down for up to 3 minutes despite it showing 'critical'.

far be it for me to complain but if it has that much left to play all those sounds and animations then it obviously has more power left. i prefer to be able to use all the useful battery life (known as the 'reserve') and i would expect the screen to dim or fade if it was really low. but in both cases the battery seems to have plenty of life.


, Blogger: Orry's Orations
Good luck, but in my opinion, you might regret it if you do find a way to shortcut it someday. I just don't think it's worth the risk, but I tend to stand on the cautious side of things anyway.
The reason why there is some battery juice left in phones and laptops before they die off, is because they need the power to save your settings. Imagine each time you charge your battery drained device, it restarts and all information is lost, or that there is no indication and your device just turns off? You can always better manage the power management of your devices' battery in the settings section.
AFAIK there is no 'turn off my phone while there's some reserve left' in the 'Settings' menu.

When i had an old radio, it would play till the batteries died. it had a small LCD which would show the frequency and a clock. when the batteries were dying, the display would dim out and eventually become unreadable. the radio would continue for another 5 minutes at best. but it used the entire battery life available. and it still worked fine when i put new ones in. no problems. the clock had to be reset that was all, no damage to any of the ICs that allowed the display to show the tuning or whatever else it was designed to do.

Now. when a laptop or cellular telephone dies out, the thing still is bright and vibrant, the display is still long from dimming out, but the phone decides that it's got insufficient power and plays tons of little animations then turns off. it even has enough life still to turn back on, only to announce the same thing, play more music and animation, and turn off. you can do that all day long.

The battery isn't nearly as low as the ones in the radio. the phone is wasting even more if it were low to play animations instead of just announcing it's too low and shutting off just like that.

But unlike the presets in a portable radio, a phone's settings are stored completely in EEPROMs inside. even if you pulled the battery off the device while it was still powered on, you don't lose your settings or phone book entires since they're stored in a sort of flash memory inside the device. so saving settings is not an issue.

On a laptop, you don't lose all your data on your hard disk when it suddenly loses power or if someone pulls the battery out. you may lose anything you hadn't saved but chances are the computer's OS, and stored items are fine. it may have to scan disk awhile from an ill-performed shutdown but that's all.

But if i'm surfing the 'net the battery should go as far as it can. i don't think having to relaunch the web browser is all that big a deal should the battery die completely.

For the proof that batteries are desigined also to fail before they've really reached their end of life, search Google for the infamous Dell 1-3-5 error.
I don't believe in throwaway goods. and those 'cell phone battery packs' which plug into the recharging port to give at best a half-hour more talk time are just that. disposable. more in the landfill.

I do, however, reuse and recycle old alkaline batteries by recharging them while still at 3/4 power for an hour in an old pre-owned or tossed-out NiCd recharger, thus saving the otherwise 'disposable' from the landfill as well as the obsolete recharging station.

But i have yet to find any way of recharging a cell phone talk-time extender.

Usually i'm not doing anything when the phone announces [prematurely] to 'recharge battery' and then show the home screen a few seconds longer to go out later. newer phones play a little 'goodbye' animation complete with polyphonic music--enough battery exists for that? so it wasn't quite dead! i could turn such a phone back on to have it do it over and over all day and of course that proves that the Li Ion pack has tons more reserve but the phone was desigined to not allow one to use it.

Must've been a way to overcome the issue which started the infamous laptop fires. i read that a Li Ion cell if it has any ounce of trouble starts a chain reaction which can cause a fire. i would only assume rather blindingly that a fully-depleted cell in a battery pack gets the spark from a charger it overheats and causes such destruction. i got that assumption from reading that Li Ion packs have trouble recharging from a fully-depleted state or are severely reduced in use afterwards.

That alone would possibly create a need for saying the phone's battery is too low to work, even though there's probably one more day or so of standby juice remaining. although i still prefer to use all the battery up. especially if it's a Ni Cd or NiMH

Now i haven't tried this in awhile but some Nokia 51xx-series show the home screen shortly after the 'RECHARGE BATTERY' bleeps, and sometimes but not always, if you hit the 'C' (Clear) key just as the home screen shows, it resets the condition, until it announces it again (in a few minutes). i haven't yet tried it on my still-working Nokia 5185i, because the battery is so old that it never goes below 3 bars of battery before silently going dead. i get 2-3 days from a 10+ year old NiMH, which i do say is impressive, but the whole time it's showing all battery bars. the third or second and it just goes out like a light lol so i never get to use my trick.
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