Battery Questions

[stevebook]

for the last step of calibration, charging after leaving it for 5 hours.
does that need to be performed immediately after or like the next day would be okay

 

[mac2be]

How much would it cost for a brand new battery anyways? If it's 100 bucks or so, then I don't really care too much about replacing it once every 2 years.

 

[aquajet]

Calibrating the battery prevents the adaptor from overcharging (or undercharging, but that's not so much of a problem) the cells.

Not quite. The point of calibrating the battery is to ensure the time estimate in your menu bar is as accurate as possible. The charging system is designed to disconnect the battery from the charging supply once it has reached a certain voltage level.

Also, two of the biggest enemies of lithium ion batteries are heat and time. Your battery will lose capacity over time, from the moment of manufacture, regardless of whether or not you use it. I still contend leaving your adapter plugged in as much as possible isn't the best thing to do, if only because you're not getting your money's worth. I mean, what's the point of having a notebook with wires attached to it most of the time?

Link

 

[mad jew]

for the last step of calibration, charging after leaving it for 5 hours.
does that need to be performed immediately after or like the next day would be okay

Well, it's probably best not to leave it too long since it's not great to store a battery with absolutely no charge. I imagine waiting a day should be fine though...

Not quite. The point of calibrating the battery is to ensure the time estimate in your menu bar is as accurate as possible. The charging system is designed to disconnect the battery from the charging supply once it has reached a certain voltage level.

My understanding is that calibrating the battery ensures the PMU or SMC knows the capacity of the cells and therefore charges appropriately. The correct remaining time in the Menu Bar was always a side effect of this, I think. I could be wrong. It happens quite often.

However, it would seem strange for Apple to insist on calibration when the only thing resting on it was displaying the correct time in the Menu Bar.

 

[aquajet]

My understanding is that calibrating the battery ensures the PMU or SMC knows the capacity of the cells and therefore charges appropriately.

This is partially correct. The exception here is, simply put, the charging circuit determines when to charge the battery based on its voltage. It doesn't rely on the reported capacity from the computer chips inside the battery because:

1. They are inaccurate and
2. Lithium Ion batteries really don't like to be overcharged. They are prone to thermal runaway if overcharged, which can lead to an explosion and fire.

 

[stevebook]

so aquajet,
what would you consider to be the proper way to use the battery if continual plug-ins are not the answer?
From that article it seems as though you should charge it to about 80% as this is where the battery prefers to sit and will lose less capacity over time

 

[mad jew]

From that article it seems as though you should charge it to about 80% as this is where the battery prefers to sit and will lose less capacity over time

The 80% thing is if you're going to be storing it for a while, but not using it. Don't worry about that for normal usage though.