Care of the Droid's lithium battery

[sustained]

Remember with older type batteries the advice was to discharge them completely from time to time to improve their life and performance?

Apparently that is actually the wrong thing to do to lithium batteries, which the Droid uses. Lithium batteries do not have "charge memory" like the older Nickle Cadmium and Nickle Metal Hydride batteries did.

Read the posts by TheAnswerIs on both pages of this thread on the Motorola forums,

The number one cause of short battery life.

I started searching for other sources and his answers about avoiding deep discharge seem correct.

Here's an interesting article:

How to prolong lithium-based batteries


It says the same as the thread above about avoiding deep discharges. Except that you should store spare batteries at 40% charge and in a cool place, even the refrigerator. And they say to try to avoid keeping fully charged batteries in a hot environment, like a hot car.


I just wanted to prevent others from continuing the old deep discharge advice which is bad for the Droid's lithium battery.

 

[Donkey Hodie]

Thanks for posting the article. I realized reading it that old habits die hard. For years, the conventional wisdom was to take batteries through as many full charge/discharge cycles as you could so that's pretty much what I've been doing with the Droid and all of the other battery powered devices I have. Technology changes but the usage habits remain the same

 

[sustained]

...For years, the conventional wisdom was to take batteries through as many full charge/discharge cycles as you could so that's pretty much what I've been doing with the Droid and all of the other battery powered devices I have. ...

I was doing it with my Droid too until I read that. Grrrr.

I'm glad it was helpful.

 

[sqchram]

Thanks for the contribution - there is a sticky ongoing with the same references in 'Tech issues, bug reports, etc'

http://www.droidforums.net/forum/te...gestions/1974-understanding-battery-life.html

Have a read there too.

 

[nikkix]

im thinking about taking my battery back to verizon...again. if it really is true what they say about charging the battery for a whole day before use. i mean, they turn it on for you and walk you out the door. that would be my third exchange of batteries though. they think im crazy.

every now and then my battery lasts 20-25 hours but thats if i barely use it at all. 10 hours is moderate usage.

i agree with the dischage cycles thing by the way. as i have stated many times. but just to clarify, i just wait as long as i can to charge it. theres a difference

 

[ShowTime]

This only becomes a problem when you fully discharge a lithium battery. Our Droids (and other devices) don't fully drain their batteries. They will always power off and remain off before the battery is 100% depleted, thus avoiding any would-be damage. So if you do occasionally let your Droid die before charging, no need to worry. I will admit though, that the notion of conditioning/calibrating these new batteries is no longer necessary. I still try and let my battery run down as low as is feasible before charging though. Just call me superstitious.

 

[takeshi]

every now and then my battery lasts 20-25 hours but thats if i barely use it at all. 10 hours is moderate usage.

Have you actually looked into what's using the battery though?

 

[nikkix]

every now and then my battery lasts 20-25 hours but thats if i barely use it at all. 10 hours is moderate usage.

Have you actually looked into what's using the battery though?

display, cell standby, and phone idle. the three biggest ones , usually. my brightness is always set to the lowest option , so i cant do anything more about the drain attributed to the display.

 

[New2u]

every now and then my battery lasts 20-25 hours but thats if i barely use it at all. 10 hours is moderate usage.

Have you actually looked into what's using the battery though?

if i barely use mine, it gets up to 50+ hours now. Moderate usage is around 25 hours, heavy is still around 8-10.

As stated we have many articles on this, much info to read.

 

[Sweettooth]

I actually did the full discharge method a couple times just for the hell of it, as mine stays above 20% for nearly a full day under almost constant usage which I'm satisfied with. My concern is I usually let the battery discharge until it gives me the 15% remaining warning before charging it. In the end I suppose it'll last long enough to justify its cost, when it stops holding a charge for a reasonable period of time, I'll just buy another one.

Nice find though sustained, doubt I'll be giving such advice anymore given most if not all phones use lithium-ion batteries. So basically it's a better idea to charge the phone when it reaches 50% or so battery life remaining, and once a month or so, let it fully discharge to calibrate the fuel gauge. Interesting.

 

[nikkix]

I actually did the full discharge method a couple times just for the hell of it, as mine stays above 20% for nearly a full day under almost constant usage which I'm satisfied with. My concern is I usually let the battery discharge until it gives me the 15% remaining warning before charging it. In the end I suppose it'll last long enough to justify its cost, when it stops holding a charge for a reasonable period of time, I'll just buy another one.

Nice find though sustained, doubt I'll be giving such advice anymore given most if not all phones use lithium-ion batteries. So basically it's a better idea to charge the phone when it reaches 50% or so battery life remaining, and once a month or so, let it fully discharge to calibrate the fuel gauge. Interesting.

does anybody else have any (besides the one article cited above) sources/proof/any info on the idea that to prolong battery life, its best to not let it go below about 40-50%?
ive never heard that before. ive heard a few things to the contrary actually.
but if that is true , id really like to know haha. cause i try not to do that now

i was under the impression that it was referring to battery storage (if you have a spare, for example)

 

[Sweettooth]

I actually did the full discharge method a couple times just for the hell of it, as mine stays above 20% for nearly a full day under almost constant usage which I'm satisfied with. My concern is I usually let the battery discharge until it gives me the 15% remaining warning before charging it. In the end I suppose it'll last long enough to justify its cost, when it stops holding a charge for a reasonable period of time, I'll just buy another one.

Nice find though sustained, doubt I'll be giving such advice anymore given most if not all phones use lithium-ion batteries. So basically it's a better idea to charge the phone when it reaches 50% or so battery life remaining, and once a month or so, let it fully discharge to calibrate the fuel gauge. Interesting.

does anybody else have any (besides the one article cited above) sources/proof/any info on the idea that to prolong battery life, its best to not let it go below about 40-50%?
ive never heard that before. ive heard a few things to the contrary actually.
but if that is true , id really like to know haha. cause i try not to do that now

i was under the impression that it was referring to battery storage (if you have a spare, for example)

Yeah I forgot to mention I was under the opposite impression as well. I'd always heard charging the battery every time it went down a little wore it out faster...

 

[Romple]

If you google "li-ion deep discharge" or "li-ion permanent capacity" loss you'll find a lot of different resources. But i'd suggest becoming acquainted w/ Welcome to Battery University. Taught me more about batteries than my college classes did!

The three biggest factors that accelerate capacity loss are high float voltage (ie: the battery's voltage at max capacity), high heat, and full discharge/charge cycles. All 3 of these cause heavy oxidation inside the cells which create a higher internal resistance which limits the amount of energy a battery can deliver. All batteries have SOME internal resistance and use some energy just overcoming that. Increasing this resistance due to oxidation forces the battery to use more energy just to overcome its own innate resistance, meaning it has less to use on your Droid.

Li-ions have no "memory" like NiCd batteries. Deep discharging a Li-Ion only serves the purpose of calibrating whatever capacity gauge is looking at the battery. This only needs to be done rarely though. In fact, low battery voltage (2.3 volt = fire hazard) is actually dangerous and all li-ion batteries have protection circuitry to monitor for low voltage levels. You're "dead" battery still has some charge, but lowering it beyond that point is extremely hazardous, and in fact without bypassing protection circuitry you cannot lower it beyond this point. Most cut off well above a float voltage of 2.3 volts.

The reason laptop batteries fail so often is because people use their laptops plugged in w/ the battery in after they were out all day and drained their batteries til they're "dry". So the battery is topped off (high float V) and the laptop gets hot which rapidly increases oxidation in the battery.

Cliffnotes:
High heat, prolonged high charge, and deep discharges = 3 biggest accelerators of capacity loss.

You do not need to do an initial full charge. This might help calibrate the meter of your Droid/laptop but there is no such thing as "conditioning" a li-ion battery.

You're best off charging between 50-90%, not using the phone for prolonged periods of time while it's on the charger, and rarely, if never, fully discharging.

 

[nikkix]

Thats all very interesting information, thanks! From what you said , i still dont understand why there is a sweet spot of when to charge your battery. Letting it die is not good, charging it for too long is not good,and high heat is not good. Why does it make a difference if i charge my battery at 20% or 60%?

Is it because the longer charge time could result in a warmer battery?

 

[ShowTime]

If you google "li-ion deep discharge" or "li-ion permanent capacity" loss you'll find a lot of different resources. But i'd suggest becoming acquainted w/ Welcome to Battery University. Taught me more about batteries than my college classes did!

The three biggest factors that accelerate capacity loss are high float voltage (ie: the battery's voltage at max capacity), high heat, and full discharge/charge cycles. All 3 of these cause heavy oxidation inside the cells which create a higher internal resistance which limits the amount of energy a battery can deliver. All batteries have SOME internal resistance and use some energy just overcoming that. Increasing this resistance due to oxidation forces the battery to use more energy just to overcome its own innate resistance, meaning it has less to use on your Droid.

Li-ions have no "memory" like NiCd batteries. Deep discharging a Li-Ion only serves the purpose of calibrating whatever capacity gauge is looking at the battery. This only needs to be done rarely though. In fact, low battery voltage (2.3 volt = fire hazard) is actually dangerous and all li-ion batteries have protection circuitry to monitor for low voltage levels. You're "dead" battery still has some charge, but lowering it beyond that point is extremely hazardous, and in fact without bypassing protection circuitry you cannot lower it beyond this point. Most cut off well above a float voltage of 2.3 volts.

The reason laptop batteries fail so often is because people use their laptops plugged in w/ the battery in after they were out all day and drained their batteries til they're "dry". So the battery is topped off (high float V) and the laptop gets hot which rapidly increases oxidation in the battery.

Cliffnotes:
High heat, prolonged high charge, and deep discharges = 3 biggest accelerators of capacity loss.

You do not need to do an initial full charge. This might help calibrate the meter of your Droid/laptop but there is no such thing as "conditioning" a li-ion battery.

You're best off charging between 50-90%, not using the phone for prolonged periods of time while it's on the charger, and rarely, if never, fully discharging.

It does not matter when you charge. Once again, yes, fully discharging a lithium battery can cause damage. BUT our phones (and nearly all other devices that use them) will power down BEFORE the battery is actually fully depleted. As you said, it is near impossible to actually fully discharge these batteries. So run it down as low as you want before charging. Also, yes high heat will damage the battery (or any electronic device for that matter) but under normal operating conditions (even use while charging) it should not reach temps capable of causing any real damage.