Battery Cycle Count? And Charging? Macbook Pro.

I leave mine plugged in as much as possible. It stops charging at 100%, discharges slowly to 95% then recharges to 100% on its own.

I use it on battery down to 40% at least once every two months.

At 26 months I have 101% design capacity and 38 cycles.

NEVER discharge to dead if it can be avoided.

Cycles are a measure of the number of times that 100% of the charge was added back. 2 recharges from 50% to 100% is one cycle, 3 charges from 67% to 100% is 1 cycle.

The 1000 cycle count is not a maximum limit for the batteries (some people have well in excess of 1000 cycles) but they are gone when used.

Cycles are a measure of the number of times that 100% of the charge was added back....

what if I never reach 100% when charging and never reach les than 10% when discharging??

in example: charging and discharging between 10 and 90 ... will OS X count cycles at all then??

Still will add up in partial cycles. But reaching 100% should eventually occur.

Keep it plugged in when near a socket so you keep the charging cycles down on your LiPo (lithium polymer) cells / battery, but not plugged in all or most of the time. When not being used for several hours, turn it off and unplug it.

And best "tip" is if its near a socket,...plug it in as long as you can (especially at home) since cycle count on the battery are the "miles that wear out the tires (battery)", however again, not plugged in all or most of the time.

http://www.apple.com/batteries/notebooks.html

"Apple does not recommend leaving your portable plugged in all the time."

ON CYCLES:

While cycle count is commonly seen to be the “miles” on your Lithium Ion pack cell in your Macbook, which they are, this distinction is not a fine line at all, and it is a big misconception to “count charge cycles”

*A person who has, for example, 300 charge cycles on their battery and is recharging at say 70% remaining of a 100% charge is a whole world better and different than another person who has 300 charge cycles at say 20% remaining on a 100% charge.

DoD (depth of discharge) is infinitely more important on the wear and tear on your Macbook battery than any mere charge cycle count. *There is no set “mile” or wear from a charge cycle in general OR in specific. As such, contrary to popular conception, counting cycles is not conclusive whatsoever, rather the amount of deep DoD on an averaged scale of its use and charging conditions.

*Contrary to some myths out there, there is protection circuitry in your Macbook and therefore you cannot overcharge it when plugged in and already fully charged

*However if you don’t plan on using it for a few hours, turn it OFF (plugged in or otherwise) ..*you don’t want it both always plugged in AND in sleep mode

LiPo (lithium polymer, same as in your Macbook) batteries do not need conditioning. However...

A lot of battery experts call the use of Lithium cells the "80% Rule" ...meaning use 80% of the charge or so, then recharge them for longer overall life.

Never let your Macbook die from power, you can corrupt files that way, and the batteries do not like it.

The only quantified abuse seen to Lithium cells is instances when often the cells are repeatedly drained very low…. key word being "often"

The good news is that your Macbook has a safety circuit in place to insure the battery doesn’t reach too low before your Macbook will auto power-off. Bad news: if you let your Macbook protection circuitry shut down your notebook at its bottom, and you refrain from charging it for a couple days...the battery will SELF-DRAIN to zero (depending on climate and humidity)…and nothing is worse on a Lithium battery being low-discharged than self-draining down to and sitting at 0

Contrary to what some might say, Lithium batteries have an "ideal" break in period. First ten cycles or so, don't discharge down past 40% of the battery's capacity. Same way you don’t take a new car out and speed and rev the engine hard first 100 or so miles.

*Also, if you’re going to store your Macbook away for a few weeks or more... make sure it has at least a 50% or so charge.

Proper treatment is still important. Just because LiPo batteries don’t need conditioning in general, does NOT mean they dont have an ideal use / recharge environment. Anything can be abused even if it doesn’t need conditioning.

From Apple on batteries:

http://support.apple.com/kb/HT1446

Keeping batteries connected to a charger ensures that periodic "top-ups" do very minor but continuous damage to individual cells, hence Apples recommendation above: “Apple does not recommend leaving your portable plugged in all the time”, …this is because “Li-ion degrades fastest at high state-of-charge”. This is also the same reason new Apple notebooks are packaged with 50% charges and not 100%.

In regards to cycles, If someone uses the macbook without the charger but doesn't turn it off and it drains to about 78 - 80% when they plug it in, are they using a cycle?

1 cycle is 100% of the battery charge used. Use battery to 50% twice is 1 cycle. Use battery once to 20% and you have used 0.8 of a cycle.

The thing to focus on is more how you use the power. Using it to <10% is not wise, use it to "dead" is bad. If you do not move much then leave it plugged in but use it on battery down to 30% once or twice a month. If you need to use it on the road, then run it on battery ... but try not to run it below 30% (you surely can find 10 minutes here and there to plug it in like for lunch, sitting on a couch, etc).

Mine is mostly plugged in. It may last 1200 cycles, or 700 cycles. When the max charge you can get in less than 80% of design-new, it is time to replace.

New notebook owners tend to overthink a lot of things with the battery being near the top of the list. Here’s what you really need to know:

1. When you get the warning you are on reserve power there’s about 30 minutes left but to be safe wrap things up and put the computer to sleep or better yet turn it off soon after getting this message. Plug it in as soon as you can.
2. Never keep using the computer untili the batter discharges. This is the worst thing you can do
3. Since you always want to be out and unplugged with as much power as possible try to keep it plugged in when you can but don’t worry if the battery is 100% charged when you unplug it. A partial charge won’t hard the computer
4. Similarly, don’t worry about keeping it plugged in after it is recharged. The computer and battery are ‘smart’ and will stop charging when it is fully charged
5. If you do keep it plugged in a lot make sure that at least once a month you use it on battery just to keep those electrons flowing. I have a monthly reminder set up just in chase.

Don’t worry about a ‘good number of cycles’. Use the battery, that’s why you bought a portable computer. Basically for most people the battery is going to keep 80% of its original charge for about 2 1/2 to 3 1/2 years. After that you’ll begin to see a gradual degradation.

Excellent, thank you very much for this. This really helped.