For the life of my previous laptop, a 2005 iBook G4, I cycled the battery once per month, every month, as suggested by Apple. Despite that, I still experienced typical battery life decline. It now gives about 20 minutes of battery usage. I'm not convinced that what Apple suggested was the best thing for it.
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Can you leave MBA on charger multiple days?
- Thread starter amitdoc2b
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184 cycles and 97% here. I just leave it plugged when I can, not always.
It is good to completely discharge the battery every now and then though, to 'keep the electrons flowing' and also calibrate properly.
There is no need to do this, the battery has a built in firmware that checks which cells have not been used recently, and makes sure that is is always calibrated properly. Your recommendation comes from back in the day before smart batteries, and honestly all you are doing is wasting the cycles on your battery to try to "calibrate" it. The only time you should ever have to do a "100%" drain is if you are having any battery issues.
Not really. I had a 2009 Macbook Pro, I have it plug in 24 x 7 in office. the battery died in 1 year. I killed two of these "smart" batteries with-in 2 years.
I didn't say leaving it in plugged in 24x7 is healthy, but the fact is that you don't need to let it drain 100% either. As long as you use the battery fairly often then there is nothing to worry about.
Battery tech
I looked at the specs for the MBA and see that it has a lithium-polymer battery. I have obtained a lot of firsthand knowledge as an RC car enthusiast regarding lithium-polymer batteries also affectionately known as LIPO batteries. LIPO batteries are the most popular batteries in RC racing at the moment. Here is what I have learned:
LIPO batteries do not have a memory. In other words you can charge it 50%, run it down, and charge it back to 100% without any sort of memory effect. This used to be an issue with older NICAD or NIMH battery technologies.
You can charge a LIPO battery to 80%, and then store it for few months without losing any of the charge or charging capacity.
LIPO batteries require a special type of charger which Apple obviously has covered.
An interesting note... the RC community is always told to be careful with LIPO batteries especially when charging. I have seen more than one battery go up in flames from improper charging. Im sure this is not an issue here.
This is what I have learned but I may be way off by comparing the two.
Especially since Apple's specs say their battery is an "Advanced" lithium-polymer.
As far as "exercising your battery", I have never heard of such a thing. Each time you run your battery you are cycling the battery. A battery has a finite lifespan. With time you will begin to see diminished capacity and less performance. As far as how long it would take to see these effects in a laptop battery I have no idea.
Cycling was used to keep nickel metal and older types of batteries running at full capacity. It does not apply to LIPO batteries. This is known as the memory effect. When you charged an older battery but did not let it run all the way through it's "cycle" and then charged it back up, you would run the risk of shortening the capacity of the battery. Again not an issue with LIPO batteries. They have no memory effect to worry about.
I looked at the specs for the MBA and see that it has a lithium-polymer battery. I have obtained a lot of firsthand knowledge as an RC car enthusiast regarding lithium-polymer batteries also affectionately known as LIPO batteries. LIPO batteries are the most popular batteries in RC racing at the moment. Here is what I have learned:
LIPO batteries do not have a memory. In other words you can charge it 50%, run it down, and charge it back to 100% without any sort of memory effect. This used to be an issue with older NICAD or NIMH battery technologies.
You can charge a LIPO battery to 80%, and then store it for few months without losing any of the charge or charging capacity.
LIPO batteries require a special type of charger which Apple obviously has covered.
An interesting note... the RC community is always told to be careful with LIPO batteries especially when charging. I have seen more than one battery go up in flames from improper charging. Im sure this is not an issue here.
This is what I have learned but I may be way off by comparing the two.
Especially since Apple's specs say their battery is an "Advanced" lithium-polymer.
As far as "exercising your battery", I have never heard of such a thing. Each time you run your battery you are cycling the battery. A battery has a finite lifespan. With time you will begin to see diminished capacity and less performance. As far as how long it would take to see these effects in a laptop battery I have no idea.
Cycling was used to keep nickel metal and older types of batteries running at full capacity. It does not apply to LIPO batteries. This is known as the memory effect. When you charged an older battery but did not let it run all the way through it's "cycle" and then charged it back up, you would run the risk of shortening the capacity of the battery. Again not an issue with LIPO batteries. They have no memory effect to worry about.
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Smart LIPO batteries have a chip in them to keep them balanced and keep them from going below a certain voltage. A LIPO battery can be made up of more than one cell in a single enclosure depending on the use.
The smart chip balances the "voltage" over each "cell" making sure they are charged equally.
Also a LIPO battery cannot drop below a certain voltage. The smart chip monitors the voltage to make sure when running off the battery it does not drop below a certain voltage. Thats why a laptop will shut down or go into standby when the voltage is getting low. If a LIPO battery goes below a certain voltage you will not be able to charge it back up.
As far as why someone would kill two batteries in 2 years, I think it is coincidence. I do not think it has anything to do with leaving the charger plugged in. The smart chip will also stop charging once the battery is charged.
This is just my opinion and an over simplified explanation.
Interesting but then why would apple publish a support doc on how to exercise your batt?
Another satanic conspiracy by apple to sell batts?
I don't think so....
As I posted previously in this thread, I did exactly what Apple said to do and my battery still gradually lost its ability to hold a charge. My 2005 ibook G4 only has about 20 minutes of battery life. Would this have happened more immediately if I hadn't religiously cycled my battery each month?
Does the 2005 iBook G4 have the same battery as the new Airs?
My Sony Vaio has a Lithium Ion battery. Is it much different from Lithium Poly batteries? My Vaio can't be running off battery for more than literally 7 min.
My company is a Mac shop which most of us use Macbook pro as our main machine. Most of us leave the macbook running 24 x 7 on our desk. Since so many of us need to replace the battery after 1 year, we end up need to take out the battery from macbook pro just to keep the battery alive when we travel.
So, no, it is NOT a coincidence. If you don't believe me, try to keep the battery in the macbook 24x7 WITHOUT calibrating the battery once a while and then get back to me after 1 year with coconut battery screenshot.
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(. I may let it get to 1% or zero every now and then.....charge it up...& go!Modern MacBooks disconnect the battery from the outlet once they reach 100% charge...you can leave it in and it will do nothing to the battery and act more like a mac mini. You will notice the bottom won't even get warm if its asleep and plugged in.
If your battery is fully charged and the light is still amber however you have a problem and should bring it to an apple store!
If you actually read the Apple support doc it specifically states that it doesn't apply to the MacBook Air....since it has a chip in it and comes pre-calibrated.