lithium-ion Battery Cycles

[thescreensavers]

Pertaining cell phone batteries.

[FONT=Verdana, Arial, Helvetica, sans-serif] Avoid frequent full discharges because this puts additional strain on the battery. Several partial discharges with frequent recharges are better for lithium-ion than one deep one. Recharging a partially charged lithium-ion does not cause harm because there is no memory. (In this respect, lithium-ion differs from nickel-based batteries.) Short battery life in a laptop is mainly cause by heat rather than charge / discharge patterns.

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http://www.batteryuniversity.com/parttwo-34.htm

I read this, and I got confused. I thought Lithium batteries only had a certian amount of charge cycles until it starts degrading.

There is something about doing that but once every 30 charges to re-calibrate the battery meter.


I recently got a car charger and been short charging like nuts, 10 min drives ..ect and now I noticed my battery is not lasting as long any more, and I thought that every time i plugged it in it used up a "charge cycle" and now that I am using up all the charge cycles the battery is degrading. Or could it be coincidence with age? (battery is 1.5 years old)

 

[QuantumPion]

Pertaining cell phone batteries.



http://www.batteryuniversity.com/parttwo-34.htm

I read this, and I got confused. I thought Lithium batteries only had a certian amount of charge cycles until it starts degrading.

There is something about doing that but once every 30 charges to re-calibrate the battery meter.


I recently got a car charger and been short charging like nuts, 10 min drives ..ect and now I noticed my battery is not lasting as long any more, and I thought that every time i plugged it in it used up a "charge cycle" and now that I am using up all the charge cycles the battery is degrading. Or could it be coincidence with age? (battery is 1.5 years old)

Fully discharging and recharging a lithium battery permanently wears it faster than partial discharge and recharge cycles.

For instance, a particular battery might be rated for 300 full charges, or 700 50% charges. You get more total use if you only partially discharge and recharge the battery every time.

Furthermore, partially recharging from 90% to 100% wears the battery proportionally the same as partially charging from 80% to 90% (down to around 30%). Meaning there is no harm in frequently recharging a mostly-charged battery. A trickle recharge from 90% to 100% does not count as an entire cycle.

Your battery performance is most likely either due to age (most lithium batteries have a half-life around 2 years), temperature (recharging in a hot car), or it may be recharging just fine and it is just the meter in your computer that is off.

Personally, I would recommend against ever deep discharging a lithium battery for the only purpose of calibrating the computer's meter. Just live with the meter being inaccurate, and giggle when you get an hour of power while the whole time the meter reads 5 minutes left!

 

[Ben90]

Car batteries as far as I know only use Lead-acid and not lithium-ion. Unless you drive a hybrid that needs to have a higher capacity.

 

[wirednuts]

you can recharge them from flat to full over 500 times, and even if you dont use them at all they still degrade after 2 years. the only way to make them last is to leave them at about 40% charge and never use it. it will last a couple more years then the normal two, but thats it. this is because a fully charged li-ion battery still eats away at itself very much the same way the battery does while you are draining it and using it regularly. and they sit in your phone fully charged most of the time when its plugged in.

thats why, in my opinion, just use them as you like. if you get 2 years out of it then you did as good as you can expect, in any case.

 

[thescreensavers]

^ ok cool, I got my old phone with around 60% charge and every few months I charge it a bit to keep it near that level.

Car batteries as far as I know only use Lead-acid and not lithium-ion. Unless you drive a hybrid that needs to have a higher capacity.

what are you talking about? I know my car's battery is lead acid, we are talking about Lithium-Ion batteries here.

 

[Cuda1447]

Man, Li-Ion batteries seem to have a lot of misinformation about them. Over at the XDA forums a lot of people claim that with new batteries you need to fully drain (to the point of them turning off) and then fully recharge them a couple of times. This is supposed to condition the battery.

I was always under the impression fully draining a Li-Ion battery was bad. I also was under the impression battery life/longevity will be approximately the same regardless of usage, excluding fully draining a battery.

A lot of people at XDA claim otherwise though. *shrugs*

 

[bobsmith1492]

Man, Li-Ion batteries seem to have a lot of misinformation about them. Over at the XDA forums a lot of people claim that with new batteries you need to fully drain (to the point of them turning off) and then fully recharge them a couple of times. This is supposed to condition the battery.

I was always under the impression fully draining a Li-Ion battery was bad. I also was under the impression battery life/longevity will be approximately the same regardless of usage, excluding fully draining a battery.

A lot of people at XDA claim otherwise though. *shrugs*

You are under the right impressions. Fully draining and recharging are remnants from older battery technologies like lead acid, NiMH, and NiCd.

Fully draining and even fully charging Lion or LiPo cells decreases their useful lifespan more rapidly. That's why the Volt maintains its battery's charge within a middle range, about 30% to 80% of the overall potential charge, so that it will last longer.
http://gm-volt.com/2010/07/14/official-chevrolet-volt-battery-warranty-is-eight-years100000-miles/

The other big factor is heat. High temperatures cause Lion/LiPo cells to degrade faster.

The best way for a Lion/Lipo cell to survive is to maintain about 40% charge around 0 degrees C: http://www.batteryuniversity.com/parttwo-34.htm