How-To: calibrate your battery

[Beer Goggles]

I've switched to using an atomic power cell.

Pros:
Never need to recharge.

Cons:
Need to wear a radiation suit whenever in the same building as the phone.

[dd4005]

Originally Posted by alphawave7

"However, a full discharge/charge will reset the digital circuit of a 'smart' battery to improve the state-of-charge estimation"

Source: Charging lithium-ion batteries


"Manufacturers rate the lithium-ion battery at an 80% depth of discharge. Repeated full (100%) discharges would lower the specified cycle count. It is therefore recommended to charge lithium-ion more often rather than letting it discharge down too low. Periodic full discharges are not needed because lithium-ion is not affected by memory."

Note in particular, the last sentence refers to full discharge with intent to override 'memory effect' as seen in NiCd/Nimh cells..Li-Ion cells suffer virtually no 'memory effects' by charge behaviour, so routine full discharge serves no purpose other than reducing overall charge cycle longevity. Insofar as charge frequency suggested, most of us are charging daily, which is plenty 'more often'.

Source: Discharge Methods

"A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.

Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate. (Read more in 'Choosing the right battery for portable computing', Part Two.)"

This suggests a full discharge and recharge is a great first step to troubleshooting charging or duration issues, which is why I suggest doing it first. All we can rely upon is actual duration before shutdown, and what the meter tells us is occurring...it's important that the meter be reporting capacity accurately before prejudicing your observed results.

Source: How to prolong lithium-based batteries

Or in other words ... everything I said

[Fury]

Interesting article i found:
Keep your charge on -- how to improve battery life on your Android phone | Android Central

Every once in a while, it's fine to let the phone run down the whole way and then recharge. This helps keep the battery meter and the battery's actual memory on the same page and give a more accurate reading for battery life. If you're the geeky type and have rooted your phone, you can delete /data/system/batterystats.bin and reboot to do the same thing. (There should be an option for this in your Recovery module, if you're not running stock.)

So root users can calibrate without draining your battrey?

[Michael]

You guys are nuts ! Just plug your phone into the charger and go to bed .

[iPeck]

Originally Posted by Michael

You guys are nuts ! Just plug your phone into the charger and go to bed .

lol. There you go

Posted from my sweet Nexus One on GB via Hit'n'Yak

[farhat_ali]

As posted by Mr. RinTinTigger, i tried caliberating the battery, but it did not work and it stills drain out withing half day with just push mail function-----no open and read is done

[hawklan]

Hey gang, Just a heads-up:
I'm fooling around with a friend's Samsung t939 that shuts down way too fast.
My friend says the battery works fine in another phone. That made me curious.
The battery voltage is fine!!

Even when I play with or rm batterystats.bin the battery% is right out.
I've been wrestling with this one since February.
I've verified that the voltage being reported is genuine.
At 4.25v (full to the gills) 100%
4.1v 10%
4.011v 0%
SomewhereBelow3.86v Powering Off.
Back in February it was somewhere below 3.66v

When i charge it with the phone turned off, the firmware seems to report correctly (big blue battery on the screen shows mostly full, and then full.)

The battery's nominal voltage is 3.7.
The phone should auto shut-off at 3.2 or live dangerously to 3.1
but it's shutting down at now 3.8

I wonder if this is what's actually been soaking everyone's battery life and nobody's thought to check the actual voltages.
Thoughts? Suggestions? Where in the OS does the shutdown voltage get dictated? Is there another factor that controls when the phone shuts itself off?

Anyway.. I've tried flashing a few different roms, dunno what could possibly survive that.. Can't afford to replace, and kind of want to solve anyway. I'm hoping this stimulates the curiosity of some clever folks with a bit more intimate familiarity with the insides of the OS...

[BarryA]

Tigger:

For your information, I followed your instructions that you posted online below . I followed your instructions to a tee. I regret to say that it killed my HTC HD2. (I think.I hope I am wrong though.) I repeated the instruction process (below) 3 times.

Upon making my 1st call after the calibration, my phone froze up and it made a weird buzzing sound. It would not stop not matter what I did, with the exception of pulling out the battery. When I pulled it out, and put it back in, the phone went totally dead. nothing lit up. I have not been able to boot it up since. Is there anything we can possiblly do?....Please help me fix my cell phone!

Barry Adler
email (direct): barryadler@verizon.net
---------------------------------------------------------------
Hey folks,

ive been asked a lot, how to calibrate your battery, to get more life out of it...

Calibrate your Battery

Calibrate the battery by completely draining it until the phone completely shuts itself off.
Turn the phone on again and let it shut itself off one more time.
Then charge your phone while it is off for over 8 hours.
This will fully charge the battery so that when the Android is turned on, it now sees the battery as full.

It is recommended to repeat this process at least one more time.

You should see a significant increase in your battery’s charge life.

Calibration of a battery can be done at any point and a maintenance calibration is recommended every month.


RECALIBRATION:

A recalibration is mostly needed, when dealing with different kernels (ROOT!). Most custom recovery images provide the option "battery stats wipe" under the menue "Wipe".

Here is how ya do it!

1. Enter Recovery Mode
2. do a full nandroid (or nandroid+ext) backup
3. Enter "Wipe"-Menue
4. do "Battery stats wipe"
5. reboot

Then you just take the steps from a bove to continue:

Calibrate the battery by completely draining it until the phone completely shuts itself off.
Turn the phone on again and let it shut itself off one more time.
Then charge your phone while it is off for over 8 hours.
This will fully charge the battery so that when the Android is turned on, it now sees the battery as full.

It is recommended to repeat this process at least one more time.

You should see a significant increase in your battery’s charge life.

Calibration of a battery can be done at any point and a maintenance calibration is recommended every month.


Tigger

[/QUOTE]

[WERA689]

Sadly, Tigger hasn't been around in quite some time.

Which process did you follow? Are you rooted? I"m not sure how simply manipulating the battery or it's use files could cause what you're reporting here.

Is there any other information that may be pertinent to this failure?

[alphawave7]

There are two processes occurring (or not occurring) when a battery discharges and recharges, electrical (electrons) and chemical (electron transference between media). I disapprove of Tigger's suggestion to restart a cell that is already exhausted, because it can irreversibly corrupt the chemical (Li-Ion, Li-Poly,etc.) and prevent it from recharging, essentially destroying the cell. Sometimes a cell that has experienced this can be 'jumpered' with another fully-charged cell to get enough juice to allow a recharge, but often they're lost causes. You need a new cell.