MBPr Battery Question

[mawyatt]

With the latest write-ups on Li Ion battery care in some of the engineering rags, the question about what is the best practice to extend MBPr battery life comes to mine. This is about managing the battery from the internal charger standpoint and how the MBPr handles long term charger connection.

I have a system where the MBPr is attached to a 27" Apple Display via the Thunderbolt connection with power pigtail. The MBPr stays powered by the pigtail almost all the time. I am not sure this is best for the MBPr battery, since it is fully charged all the time and only discharges when removed from the display, which isn't very often. The mentioned write-ups indicate maintaining a modern Li Ion battery at 100% charge will shorten it's life span, while maintaining at 40% will extend it's life.

Anyone with an engineering background knowledgable about this situation have any comments? Anyone know anything about the internal battery charger within the MBPr, maybe chip utilized?

Thanks in advance,

 

[Weaselboy]

Here is some info from Apple that may help you. On that page they suggest just running off the battery once a month.

I have the same setup you do with a Macbook Air and rarely use the laptop away from the desk. I just run it off battery power one day a month and don't sweat it beyond that.