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How do I use my MacBook Pro to preserve battery life?
- Thread starter pilesofstones
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Run on battery whenever you need to and plug it in whenever you can. You can plug or unplug any time you need to, regardless of the charged percentage, and you never need to completely drain your battery. Just make sure you don't run on AC power exclusively, as your battery needs to be used regularly to stay healthy.
The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it. 
Most people don't pay attention to sticky threads, which is why we end up posting the same answers a few thousand times.
AppleCare doesn't cover consumables like the battery. Officially they will only replace the battery if the metrics they use to measure its health indicate it is not behaving "normally".
I have first hand experience of this on a MBP covered by AppleCare. They initially would not replace it as their metrics indicate its performance was in line with the usage metrics gathered by the machine. When it subsequently deformed, yet the metrics still showed normal they replaced it (and the trackpad it had damaged). The previous battery was also replaced on the machine as it was operating outside its expected thermal envelope.
They might afford some extra good will occasionally if you have AppleCare, but the default position is that the battery is only covered if it fails prematurely, not if it is consumed "normally".
OP the battery is a consumable part that is affected by a plethora of variables, many of which conflict.
For example on the one hand charge cycles will deplete its capacity and life, but conversely Li-ion/polymer batteries don't like to remain fully charged for extended periods either. Therefore if you use it, you will deplete it, but if you leave it permanently at 100% it will also affect its life and capacity.
I would advise reading about how these batteries work as this will set your mind at ease, reading threads about battery failure will often just heighten your concerns and have you following "old wives tales" that will only inconvenience and compromise your usage of what is ultimately a very expensive mobile device.
You will find a few basic rules that "may" reduce your risk of premature battery failure, but even these won't ensure optimal battery performance as their are so many factors at play:
1) Avoid exposing the battery to extremes of temperature
2) Avoid leaving it fully charged, especially when not using the machine for a while (I generally leave my machine at 50% if i'm going away and won't be using it).
3) If you are largely tethered, occasionally unplug it and put the battery through a cycle.
4) Avoid deep discharges. That doesn't mean if you're using the machine stop using it at 10%, whats the point of having a machine with great battery life, if you're not going to use it when needed. But rather i'm referring to leaving it on suspend for a month, unused, uncharged, so every ounce of power is slowly drained from it. If you're not going to use the machine for weeks, shut it down. I think this is less of an issue these days, as many machines have complex battery protection systems in place.
Most important of all, try to accept its a consumable part. Use it as needed. Don't take drastic measures to try and protect it, as these will ultimately prevent you using what you're actually trying to save, and worse still it will still fail eventually anyway. As I've said on other threads, you can't have your cake and eat it. If you don't eat it, it will either go stale or something else will eat it :/
For example on the one hand charge cycles will deplete its capacity and life, but conversely Li-ion/polymer batteries don't like to remain fully charged for extended periods either. Therefore if you use it, you will deplete it, but if you leave it permanently at 100% it will also affect its life and capacity.
I would advise reading about how these batteries work as this will set your mind at ease, reading threads about battery failure will often just heighten your concerns and have you following "old wives tales" that will only inconvenience and compromise your usage of what is ultimately a very expensive mobile device.
You will find a few basic rules that "may" reduce your risk of premature battery failure, but even these won't ensure optimal battery performance as their are so many factors at play:
1) Avoid exposing the battery to extremes of temperature
2) Avoid leaving it fully charged, especially when not using the machine for a while (I generally leave my machine at 50% if i'm going away and won't be using it).
3) If you are largely tethered, occasionally unplug it and put the battery through a cycle.
4) Avoid deep discharges. That doesn't mean if you're using the machine stop using it at 10%, whats the point of having a machine with great battery life, if you're not going to use it when needed. But rather i'm referring to leaving it on suspend for a month, unused, uncharged, so every ounce of power is slowly drained from it. If you're not going to use the machine for weeks, shut it down. I think this is less of an issue these days, as many machines have complex battery protection systems in place.
Most important of all, try to accept its a consumable part. Use it as needed. Don't take drastic measures to try and protect it, as these will ultimately prevent you using what you're actually trying to save, and worse still it will still fail eventually anyway. As I've said on other threads, you can't have your cake and eat it. If you don't eat it, it will either go stale or something else will eat it :/
I am a bit confused by your question. How you use the battery does not affect how long the computer will 'last' in the least. If your battery performance should degrade dramatically before that, you can always get a new one.
Just for reference: my battery is now at 750 load cycles in 622 days. On average thats over a full load/depletion cycle per day; so yes, I am abusing my battery as hard as possible. Its still at 80% of its original capacity. These batteries are really good and last three times as long as those of most other laptops.