Do I need to “discharge” a lithium ion battery? Is it bad to run the laptop battery all the way down?
There is no need to “discharge” or fully drain a lithium-ion laptop battery.
What should I do if I use my laptop battery infrequently?
If you only use a laptop for infrequent travel, Apple and other manufacturers recommend charging and discharging the battery at least once per month.
Store your lithium-ion battery at 40% charge in cool place.
How many charge cycles does a new battery come with?
There is no standard definition of what constitutes a charge cycle! Nonetheless, most new laptop batteries are considered to ship with around 300-500 charge cycles. Apple claims that the MacBook Pro and MacBook Air batteries are designed to deliver up to 1000 full charge and discharge cycles before it reaches 80 percent of its original capacity. [Source: Apple.com]
How are “charge cycles” counted? Do partial charges count as a full charge cycle?
There is no standard definition of a charge cycle. Less-than-full discharges actually contribute to a longer battery life and are more representative of realistic use patterns.
However, practically speaking, lithium-ion batteries do experience degradation as the battery is discharged and recharged. Generally, li-ion batteries count cycles as units of 100 percentage points. If you discharge a lithium-ion battery to 75% and charge it to full afterwards, you’ve used 25%, or one quarter of a cycle. If you drain it to 50% the next day and then charge it, now you’re at 75% of a cycle used. Another 25% discharge will complete the cycle.
For practical purposes, it’s not worthwhile to obsess over charge cycles. A laptop is a tool for enhancing your productivity: micromanaging its charge cycles is a waste of your time and even if you try to min-max it, will not significantly delay the inevitable.
Battery University has a very technical explanation of charge cycles, which you can read here.
Do shallow charges confuse the battery?
Lithium-ion batteries don’t suffer from “confusion”, but the clock on your computer that estimates how much longer the battery will last can get out of sync as a result of shallow charges. [Source: Ars Technica]
NiCad batteries had a “memory” of what their total charge capacity was, and they’d get “confused” by shallow discharges / partial recharges. This does not apply to lithium-ion batteries. [Source: Ars Technica]
What should I do with a brand new laptop battery?
Plug it in and charge it all the way to full. When it’s full, disconnect it and use your computer “on battery” for a while. Continue to alternate between “on battery” and “charging”.
If you’re on an Apple computer, run Software Update to ensure you have the latest software. Apple periodically releases updates that may improve battery performance.
Do laptop batteries get worse with age?
How can I maximize my laptop battery’s lifespan?
- Dim the screen
- Set your desktop color to black
- Look at dark images/backgrounds instead of light/white images
- Turn off WiFi
- Close as many applications as you can
- Copy media from the optical drive to your hard drive
- Keep the laptop cool. Use a cooling pad (not USB-powered)
- Upgrade to a 8- or 12-cell battery
- Invest in a portable power pack
Related: Make your laptop battery last longer in Windows 8 [TechRadar]
What’s the BEST way to treat a laptop battery?
- Never run it down to empty
- Don’t let it overheat
- Do not leave your laptop plugged in 24/7
- Operate between 50° to 95°F (10° to 35°C)
Ideal battery use: a student uses her notebook in class and then plugs it in in her apartment to charge. The battery juices stay active.