[Droid Incredible Android Development] galaara98:
OK now I'm Done :)

Everyone needs to stop judging kernel battery life by ANYTHING 90% - 100%. This goes for stock, tiamat, incredi, invis, everything. Judge the kernel from 89% to 3%. Im on tapatalk, so ill submit this and go find a computer to explain.

OK a repeat lessen (yes you guys have heard this, but maybe i can translate it)

I'm an engineer so your going to get a fire hose lesson in batteries.

In most our lives there have been 5 types of rechargeable batteries

NOTE: Alkaline Batteries and Lithium Batteries ARE NOT RECHARGE ABLE!!!! (Get Hot, Go Boom) Alkaline Manganese, Lithium-Ion, and Lithium-Ion Polymer are.

Nickel-Cadmium (NiCad)

PRIMARY ADVANTAGES:

Very Resistant to damage due to no charge for long time, last more recharge cycles than most technologies

Competes with regular Alkaline batteries very well (slightly less volt, but rechargeable)

Very Simple Charging (pump in about 1.4v constantly until it's full)

PRIMARY DISADVANTAGES:

Very marked negative temperature coefficient (heat and cold change the battery)

Power output (mAh) decreases with % charge capacity (slightly weaker as you use)

1.2 V means must have several cells in serial to reach common voltages (except for the AA and AAA)

Overcharging corrodes and releases gas

Full Discharge damages the Cells

Cell Memory (voltage will fall to the spot you most commonly stop charging)

Cadmium is a toxic heavy metal

Nickel-Metal Hydride (NiMH)

PRIMARY ADVANTAGES:

Cost

A NiMH battery can have two to three times the capacity of an equivalent size nickel-cadmium battery

FAST Charging! Charging is Generally handled by Delta Voltage or Delta Heat (fast charge until too hot, slow down)

Limited Trickle Charge (over 20 hours is not recommended)

Corrosion and Gas safeties (may break your battery, but save your equipment)

PRIMARY DISADVANTAGES

Self Discharges [5% per day after first charge, < 1% per day there after] (there are Special LOW self discharging NiMH)

REQUIRES INTELLIGENT CHARGING (cannot be charged with constant voltage [btw NEVER use a NiCad Charger on NiMH for this reason]

COMPLETE DISCHARGE REVERSES POLARITY at last few percent (VERY BAD)

Power output (mAh) decreases with % charge capacity (slightly weaker as you use)

Lithium-Ion (Li-Ion)

PRIMARY ADVANTAGES

One of the best energy densities (SIZE versus power)

No memory effect

4.2v makes great combination for electronics

Power output (mAh) is consistent right up to the last few %

Shape-able (Li-Ion can be in "pouches"), though most are still in series of cells like normal.

Low Weight (very cool for small devices)

High Current per cell (depending on the other material with the lithium)

LOW Self Discharge: 0% for dumb lithium, to 5-10% per MONTH for smart batteries.

Very low environmental impact if improperly disposed.

Supports incredible variety of charge. Just shove anything at it (even LOW volt is fine, but stop when full)

PRIMARY DISADVANTAGES

Cost. They just plain cost more to make (i don't know how ebay does it, supply and demand i guess)

Cell Life is Permanently lost in ways: Total capacity per charge slowly lessens with:

TIME: The moment the battery left the FACTORY it began it's life span. If you bought 2 IDENTICAL batteries off the shelf, but one was made 1 year earlier they will have different HOURS of capacity.

HEAT: The most obvious source of heat is HEAT! Hot cars, hot showers (slacker radio baby), near vents, anything that raises the battery temperature above its threshold is permanently, irreversibly, lowering its next charge to be slightly smaller.

FULL CHARGE: Holding the Voltage at it potential. I have both oral, and 100s of written sources that Li-Ion batteries should NEVER be HELD in their quoted potential (for instance: look at http://batteryuniversity.com/learn/article/the_high_power_lithium_ion) there is simple statement in their that says you can save cell life by minimizing the time the battery stays at 4.2v) If you get the engineering manuals for IBM laptop batteries you will find they always stop at 98% of potential.

OVERCHARGE: Beyond manufacture specification will cause plating of components (like plaque for a battery). Overcharging may trip a smart battery safety to disconnect, or vent gas to prevent flame (lowering life span and possible damaging device). Continues OVERCHARGE will most likely result in flames.

COLD: You can USE a Li-Ion battery in cold temperatures with no effects. Just don't CHARGE!!! It will plate some of the components (like plaque for battery)

FULL DISCHARGE: full discharges just reduce the cell(s) lifespan. You gain nothing (EXCEPT a true measurement of 0%, which sometimes is nice)

Lithium-Ion Polymer (Li-Pol or Li-Poly)

PRIMARY ADVANTAGE

Basically same as Li-Ion, but in addition:

Li-Ion is a shape-able gel [now there is a cover obviously, this cover is generally METAL, or equivalent protection], in Li-ion Poly, the Lithium is ... best way i can think to describe to you: fused into plastic. The battery itself is already a slightly flexible plastic that needs no metal. Makes it very light.

Generally suffer little to NO self discharge

PRIMARY DISADVANTAGE

Same as Li-Ion, in addition:

No Metal between your device (or your hand, means over charging is DANGEROUS... Therefore batteries have brains to NOT ALLOW THEM TO BE OVERCHARGED Doesn't matter what the Device says)

Even Faster Permanent Cell Life than Li-Ion (Depending it can be 500 CYCLES reduces battery by

20%

[can you say EBAY] to more expensive batteries 10000 Cycles reduces by 20%)

Must be charge with constant rate

Trickle Charging actually LOWERS VOLTAGE in Cells, not just Capacity. this could make your device suffer from BROWNOUTs (Can we say random reboots anyone)

Alkaline Manganese

Well none of us really care :) but

PRIMARY ADVANTAGES

1.5v Direct Competitor to AA and AAA

If Completely drained can be recharged to full 1.5v, therefore best used for devices that drain them all the way (like a remote control)

Resist leaks from charging (HEAVIER Material than standard Alkaline)

PRIMARY DISADVANTAGES

They Fall to MAX 1.3v output if not properly cared for

So now what does that mean for everyone:

FIRST, this is the best post on the Internet, BAR NONE, on your Battery meter itself:

http://xdaforums.com/showthread.php?t=871051

In Summary, your device charges your battery to 100% (honestly it may even be just 98% [I KNOW IBM LAPTOPS do] then lets it dip to 90% (AND IT LIES!!!) and says it's at 100%, it then Charges back up to 98%/100% [LYING THE WHOLE TIME]. The moment you pull it off the charger your device has a problem, tell the user that the battery is INSTANTLY somewhere it wasn't suppose to be, or keep LYING and ease them into the bad news. If the SECOND you pulled the device of the charger it coincidentally was at 98% it will fall normally. If it happened to be at say 92, it will fall to meet the true 88-90% (as it gets there) over the next say 5 minutes.

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So Super Battery Charge(er)... SBC is software (charging intelligence in the kernel if you will) on the Device that instead of letting the Battery goto 100%, then Secretly back to 90% and back up, holds it steady at 99.99% and up (if you actually talk on the phone or draw enough juice you can keep your charger pumping solid when at "100%"...that might actually heat your battery up something real fierce, other that that you are just playing by the heat, life rules. Be aware that batteries themselves can have circuits that still protect them from a full charge. this is why when you compare to others or even your last day, their is so many different results.

Bump Charge is just DEFEATING the software and charging to 100%. BUT the battery, and in fact your charger itself may too, has a circuit board that will still properly charge a Li-ion and Li-Pol battery. So you will actually have a perfect 90-100-90 cycle ANYWAY.

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That is WHY all AOSP Gingerbread turns Green at 90%, That is why Your Percent Falls so quickly.

As far as SBC, Your percent might not fall from 100% to 90% like above, but each day reduces what the scale means.

So imaging if your batter was 1000 mAh (FOR SIMPLICITY) 100% means full, 90% means 900mAh...with me?

So lets say you wake up play World war, read news, twitter, facebook, use GPS to goto work [cause we're lost??? why do we do that?] whatever, and its at 90% (sweet, we avoided the battery drop of doom... used 100mAh)

Now in 1 month your battery is only capable of 900mAh (FOR SIMPLICITY.. don't cite me on the actual), All of your apps, your screen, your GPS draw the same load as they did last month... but 100% is only 900mAh.

So you do all the same things and when you show up to work your at 88%, Super simplified, and you do your own real world numbers..

SO like I said above some batteries can decrease their maximum capacity extremely rapidly (I don't have a worst cast for Li-Ion, but the #s i found in Li-Pol worst case was 20% less capacity in 500 cycles, and if you really want me to find out what's in the $5 crap we are all buying on ebay i would VENTURE the capacity falls faster than anyone here thinks) Mix in Heat of fast charge, damage of SBC, leave your phone on the "Universal Holder" as a GPS with the HOT vent Air or direct sunlight... AND Then have the nerve (i'm being sarcastic, not condescending) to say i'm leaving CM7 because no kernel can hold a charge... well buy a bigger, more recently produced battery, or two :) But laws of chemistry RULE and the kernel devs can only do so much.

Aaron