No longer reserve battery?

[lbjandai]

Ever since I've had my Retina Macbook Pro, when my mac's battery dies, it really dies. It takes a few minutes to boot back up. I'm sure this explained by something, but it's annoying as heck.

My old pre-unibody MBP would die and then id plug it in and it would immediately turn on again.

Can anyone explain this?

 

[Mac.User]

Different battery technology. Older batteries if they REALLY hit 0 they could have issues ever charging or powering on again so there was a buffer. New batteries no longer have that issue.

 

[lbjandai]

wish there was a way to change this. Psychologically, I only go grab my charger when the battery completely dies, not when I get the pop up alerts.

 

[goMac]

wish there was a way to change this. Psychologically, I only go grab my charger when the battery completely dies, not when I get the pop up alerts.

It's supposed to go into Deep Sleep which would make a sleep-by-battery-buffer redundant.

The buffer was also useful when you could swap batteries as it would keep the machine alive while the battery was out, but that's also no longer possible.

 

[Azathoth]

Different battery technology. Older batteries if they REALLY hit 0 they could have issues ever charging or powering on again so there was a buffer. New batteries no longer have that issue.

The definition of when a lithium-ion battery is fully discharged is somewhat up to the manufacturer. The case of Apple because they want to be able to guarantee up to a thousand cycles, I would guess that they purposefully set the machine into hibernation once the voltage per cell reaches something like 3.4V although this might not completely empty the cells in the battery doing so will greatly prolong the lifetime of the battery in terms of number of cycles.

AllModern lithium-ion battery packs have protection to prevent over discharge as over-discharge can cause irreversible damage to the battery.

 

[Astroboy907]

AllModern lithium-ion battery packs have protection to prevent over discharge as over-discharge can cause irreversible damage to the battery.

+1, this is why you should never store a computer with a completely dead battery (I believe apple says to store at 50%).
From what I remember, the per cell voltage of lithium batteries is like 3.3v. Pretty much anything below 2v and the protection circuitry will actually not let the battery charge because it is more hazardous to the battery.

 

[Azathoth]

I can recommend reading:

http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries