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battery cycle questions

J

JMartin23

macrumors member
Original poster
Dec 28, 2009
38
0
Every time you charge the battery, it counts as a load cycle, right?



1. If i'm charging my battery at home, and it's not fully charged, and then replug it in once I'm in class, did that just count as two load cycles?

2. If the battery is fully charged; should you unplug the charger, or let it continue to charge while at home, so as not to run down the battery and then waste another cycle.

3. If applecare only replaces batteries up to 300 cycles, that means that my battery is irreplaceable in less than a year? wtf?

4. how do you guys usually charge your batteries to get the best life out of it? I've calibrated it, and have noticed that the battery life got worse???



A note: the charger is plugged in right now, and it's fully charged, but the battery is only at 99%... So i've already lost 1% of my battery life after 2 charges?
 
JMartin23 said:
Every time you charge the battery, it counts as a load cycle, right?



1. If i'm charging my battery at home, and it's not fully charged, and then replug it in once I'm in class, did that just count as two load cycles?

2. If the battery is fully charged; should you unplug the charger, or let it continue to charge while at home, so as not to run down the battery and then waste another cycle.

3. If applecare only replaces batteries up to 300 cycles, that means that my battery is irreplaceable in less than a year? wtf?

4. how do you guys usually charge your batteries to get the best life out of it? I've calibrated it, and have noticed that the battery life got worse???



A note: the charger is plugged in right now, and it's fully charged, but the battery is only at 99%... So i've already lost 1% of my battery life after 2 charges?
Click to expand...

I'm pretty sure that one cycle is the equivalent of 1 full discharge and subsequent charge. In other words, if you discharge your laptop from 100% to 0% and then recharge it back to 100%, that counts as one cycle. You could also discharge your laptop from 100% to 50% twice, charging it up to 100% after each discharge, and that will also count as one cycle.

You get the picture.
 
JMartin23 said:
yes i do.. any insight into the other questions?
Click to expand...

Apple recommends calibrating the battery every month or so, and using the laptop on battery every few days at least. I don't think you should be scared of leaving the charger plugged in. As long as your battery gets some use every few days, you should be fine.

I just leave my MBP plugged in most of the time. If I need to take it somewhere, I use it on battery power, and when I get back, I just plug it in again. I calibrated my battery when I first got the MBP, and I plan to do so again in a month or so.

Overall, I'm just going to use the battery as it was meant to be used. It's supposed to last for 1000 charge cycles anyway, so I'm not too worried about general use. Before the battery needs replacement, I'll probably have a new computer (at least for my use pattern). It should take you a couple of years at least to wear out the battery if you use it moderately.

I'm also noticing some weirdness with the charge indicator. Mine has said 97% at full charge, 99% at full charge, and now 100% at full charge. Maybe it just needs to be broken in :confused:
 
Most notebooks do not start charging a battery until it lost like 3-5 % of charge.
So if you unplug it and it looses 2% and plug it in again it usually does not charge it back to 100%. You need to loose a little more charge to trigger the charging to 100% than just 1%.
I don't know how Apple really does it as I don't own a MBP yet but most other charging control systems in notebooks to it this way.

For everything you might want to know about batteries this is a very good source. batteryuniversity
 
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