I want to know:
Does leaving the cord save battery cycles?
is it better to have cord in, or never keep it in unless your are charging to full.
The link on calibrating said nothing beyond just drain, and recharge.
(1) if you go a long period of time without discharging the battery through use, you
will ruin its ability to hold a long lasting charge. Batteries that have gone a half a year without charging may have a runtime measured in
seconds as a result of not being exercised regularly. or they may appear to run well at first and then suddenly remaining power estimates drops from 2 hrs to 15 minutes over the coarse of a few minutes. The general rule is that battery runtime is determined by how much it's
used to being discharged. If you never discharge it, its runtime will change to reflect that.
(2) cycle count is only increased through charging. if you never discharge the battery, the cycle count does not advance. discharge/recharging it periodically ("recalibrating"/"periodic cycling"/"etc") will slowly increment your cycle count. Avoiding exercising your battery to preserve cycle count is a bad idea because it can lead to sudden failures as described in #1. But on the other hand, overly-frequent exercising is wasting your cycle counts needlessly. Half a discharge followed by fully recharging it, twice, would add one cycle. (it counts partial cycles)
(3) except through defects, batteries need to be replaced in one of two cases. either when you have not exercised the battery (see #1) enough and the runtime has become unacceptably short (or won't run on battery at ALL) or in the event you've simply used the battery enough to wear it out due to cycles (see #2)
(4) A cycle count of over 300 is standardly referred to as "consumed". A cycle count over 100 is "used". Used batteries should still be useful but will have a noticeably shorter runtime on battery that they did when they were new. Consumed batteries will have a very short runtime, usually 15-25 minutes. You can view your battery's current cycle count in system profiler under Power. There is no way to reset your cycle count, it's like the odometer in your car. Apple ends the warranty on your battery when the cycle count passes 100, and extended warranty (applecare) does not apply to batteries ever. Batteries are like brake pads on your car. You should expect to replace them occasionally over the lifetime of the product.
