Will Macbook Battery be Damaged by Continuous Charging?

AirMonty,

I have the same set-up - tethered Apple Thunderbolt Display to my 2011 MacBook Pro almost 24/7. I have a reminder set for every two weeks in which I disengage the Display and let my battery run down to approximately 30-40% or so before plugging back up. I've been doing the for over two years now and my battery health is now at 98.6%.

You need to keep those ions working - give your battery some breathing room every two weeks or so.

Clinton

Thanks for the tip. Just replaced my old MBA with a new one and want the ~12hr battery to keep for when I actually do go mobile . . .

All batteries in any device are a consumable meant to be replaced eventually after much time, even under perfect use conditions.

➕If the massive amount of data that exists on lithium batteries were to be condensed into a simplex, helpful, and memorable bit of information it would be:

1. While realistically a bit impractical during normal everyday use, a lithium battery's longevity and its chemistry's health is most happy swinging back and forth between 20% and 85% charge roughly.

2. Do not purposefully drain your battery very low (10% and less), and do not keep them charged often or always high (100%).

3. Lithium batteries do not like the following:

A: Deep discharges, as meaning roughly 10% or less. Avoid this in all instances if you can. This is hard on your battery.

B: Rapid discharges as referring to energy intensive gaming on battery on a frequent basis (in which case while gaming, if possible, do same on power rather than battery).

C: Constant inflation, as meaning always or most often on charge, and certainly not both in sleep mode and on charge always or often.

From Apple on batteries:

http://www.apple.com/batteries/notebooks.html

http://support.apple.com/kb/HT1446

"Apple does not recommend leaving your portable plugged in all the time."

Contrary to popular myths about notebook batteries, there is protection circuitry in your Macbook and therefore you cannot ‘overcharge’ your notebook when plugged in and already fully charged.

However if you do not plan on using your notebook for several hours, turn it off (plugged in or otherwise), since you do not want your Macbook ‘both always plugged in and in sleep mode’.

Do not perform “battery calibration” on your current Macbook. There is no calibration of current Apple portable Macbooks with built-in batteries.

A lot of battery experts call the use of Lithium-Ion cells the "80% Rule", meaning use 80% of the full charge or so, then recharge them for longer overall life. The main quantified damage done in the use of Lithium Ion batteries are instances where the internal notebook battery is “often drained very low”, this is bad general use of your notebook battery.

danieliwvernick wrote:

Would it be more benefical to the battery to run it down to like 5%, instead of 40%, a few times a month?

Also, I'm confused because the link I previously posted also says all Macbook Pros should be calibrated if attached to AC power...

PowerBook G4 (15-inch Double-Layer SD), MacBook (all models), and MacBook Pro (all models)

The battery calibration for the PowerBook G4 (15-inch Double-Layer SD) and any model of MacBook or MacBook Pro has been updated because of a new battery released with this computer. With these computers, follow these steps to calibrate your battery:

If you normally leave your Apple portable computer connected to AC power and very rarely use it on battery power you may want to perform this process once a month.

I believe the part you quoted refers to all MacBook Pros with removable batteries, since the PowerBook and MacBook models also mentioned are removable battery models. The earlier passage in the same article that says "Current Apple portable computer batteries are pre-calibrated and do not require the calibration procedure outlined in this article." seems to indicate that if your MacBook Pro has a non-removable battery, you don't pay attention to the part you quoted.