Home Forums Peripherals & Multimedia iTunes, iPhone, iPod, iPad, Apple TV iPad battery got run down to zero.

... Given your 100% discharge is a single incident it is doubtful any reduction in battery recharge cycles would be unnoticed and undetectable. ...

My wife and I have both inadvertently discharged an iPhone, iPad, and Watch 100% more than once, and all continue to work perfectly with no perceptible reduction in battery capacity or life.

According to Battery University there are three primary factors effecting Lithium Ion battery life including

Not stop charging when full, but don't leave it plugged in and charging all the time. In other words, use it in battery only mode for some period of time.

Some people use a laptop like a desktop model—plugged in, sitting on a desk all the time, and I understand V1 to say this type of operation is not a good thing for the batteries.

The question is asked, “Should I disconnect my laptop from the power grid when not in use?” Under normal circumstances this should not be necessary because charging stops when the Li-ion battery is full. A topping charge is only applied when the battery voltage drops to a certain level. Most users do not remove the AC power, and this practice is safe.

and the last few posts finally pushed me to it, and my answer from two levels of techs was that current power block and battery technology make it unnecessary to ever unplug one.

I feel it's necessary to point out that sometimes even the experts can be wrong, particularly when they are speaking entirely from a theoretical point of view and lack real-world experience. "We designed it to work this way, so it works this way" doesn't always hold true.

When discussing this with the boys at the shop, we were pretty much all in agreement that the swelling would probably not have occurred if I hadn't left it on charge all the time. That's the voice of experience speaking.

So, V1, have you seen any swollen iPads?

Both points are well taken. I would also point out that although the fundamental lithium Ion battery technology is relatively stable, the technical minutia changes with almost every release. So what is true for this years model may not be true for last years model or next years model.

The recommendations for charging, calibrating, prolonging battery life continue to evolve and it appears Apple's documentation on the subject is often slow catching up. I do not use a laptop, but my daughter and a good friend both had MacBooks destroyed by swelling batteries and I know Apple ate the cost of replacing a lot of MacBooks, Airs, and Pros for that very reason and Apple does NOT like to repeat its mistakes. So it would seem possible both positions were valid, but maybe not on different model and age Apple laptops, but I can only indirectly validate that proposition.

What I do know is Apple builds a LOT more iPhones and iPads than it does MacBooks and the iOS devices account for 90 to 95% of Apple's cash flow so it would follow that Apple would put the latest and greatest technology there first. Given

• the very nature of the iOS devices dictates they will be unplugged far more than they will be plugged in
• battery life including number of recharge cycles as well as how long a charge lasts is a major marketing point for all smart phones
• I am unaware of any incident involving battery swelling in iOS devices

…ergo if I had a laptop I would follow V1's advice because my experience with other Apple devices that rely on battery power.

Hi,

My first four Mac laptops virtually never left their places on my desk and, consequently, were virtually never used on battery power.

Apple’s on-line and/or verbal guidance was to completely run the batteries in those Macs down once every month, which I did with no apparent resultant issues.

I recently got a new MacBook Pro, and I once again called Apple to ask for guidance, and this time I was told that I should leave my MBP plugged in 100% of the time…that there’s no need to either work the battery or run it down completely.

This Batter U page <http://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteriesHow to Prolong Lithium-based Batteries - Battery University> says:

"The question is asked, “Should I disconnect my laptop from the power grid when not in use?” Under normal circumstances this should not be necessary because charging stops when the Li-ion battery is full. A topping charge is only applied when the battery voltage drops to a certain level. Most users do not remove the AC power, and this practice is safe.”

However, since it sounds like that advice is directed towards users who leave their devices plugged in when they’re not using them on battery power it doesn’t seem applicable to my situation.

Consequently, I’m wondering what guidance Battery U offers to users who virtually never unplug their Macs from day one to day n.

I understand that in theory I should never need use my battery, but at the same time I’m wondering if that theory has actually been road-tested on batteries that have remained totally unused for periods as long as the lives of many Mac laptops which frequently are in use for 5-6 years and more.

I’ll really appreciate a definitive answer to my question.

(Response)

Artie,

No situation is perfect as high temperature also plays a role in battery life. Keeping a laptop plugged in provides a sufficiently long service life when kept moderately cool. You may want to disconnect the main if the laptop is not used for a few days.

Isidor Buchmann| CEO

Cadex Electronics Inc.