LAPTOP BATTERY CARE

First of all it's necessary to unfold a myth that persists in many peoples head. The battery memory effect. In lithium-based batteries this is in fact a myth, it only applies to older Nickel-based batteries. So fully discharging and charging the battery is completely useless and even harmful. The modern lithium battery can be charged regardless of its current percentage, given that it has absolutely no negative effect in its performance.

SHOULD I REMOVE THE BATTERY WHEN A/C IS PLUGGED IN?

Leave the battery in, it will serve as a backup in case of power failure, so you won't lose your work. Most laptops have a chip built into the battery which stops it from charging once it's full. So you're not wasting the battery at all, just leave it in.

However there's a disadvantage in keeping the battery in its socket when the laptop is plugged in, but only if it's currently suffering from excessive heating caused by the laptop hardware.

So:

- In a normal usage, if the laptop doesn't get too hot (CPU and Hard Disk around 40ºC to 50ºC) the battery should remain in the laptop socket;

- In an intensive usage which leads to a large amount of heat produced (i.e. Games, temperatures above 60ºC) the battery should be removed from the socket in order to prevent unwanted heating.

The heat, among the fact that it has 100% of charge, is the great enemy of the lithium battery and not the plug, as many might think so.

BATTERY DISCHARGES

A laptop battery can be charged 300-1000 times. The actual number depends on the way it has been treated.

Total discharges, i.e., to the cut-off point, can destroy battery cells. Not all cells in a laptop have the same voltage. Your laptop’s battery gauge only displays the state of the whole battery. If a cell goes below a certain voltage it will be destroyed. Therefore, it is safer to stop working when your battery level reaches 20%. The low battery level can be configured under Vista in the advanced power settings applet. Vista will warn you when the battery reaches the low battery level.

In contrast to NiCd (Nickel-cadmium) and NiMh (Nickel-metal hydride) batteries, Li-ion (Lithium-ion) batteries show no memory effect. That is, it will do no harm to the battery if it is re-charged before it is empty. Full discharges will strain the battery.

HOW TO PERFORM A CALIBRATION (FULL DISCHARGE)?

Now, when it comes to rechargeable batteries there are a lot of variations. But one thing that is universally true for all the rechargeable batteries is that, from the day they're manufactured ... they start to lose their ability to hold the charge. Although the rate is small (depending on the type) but even without you having to do a Calibration (more lately), still at the end they'll all going to lose their ability to hold the "charge" nonetheless which is defined either by their "life/years" or recharging cycles (which also changes according to the battery type). 

How to do it:

Usually in your Laptop BIOS you'll find an "option" which lets you discharge your battery. But I don't know if all the manufactures do this. So in that case the best things to do is to...

1. Make sure your battery is charged at least 95% or above of its full capacity before proceeding.

2. Now remove your AC adapter and let your Laptop run using the battery.

As most know, when your battery reaches its critical levels Windows, Mac OS, GNU/Linux, etc gives you warnings and if you don't do anything about it, then the BIOS automatically puts your operating system to sleep or stand-by mode. So wait until your battery is so drained which forces your OS to put itself to sleep mode.

3. Immediately after your PC/Laptop goes to sleep mode, then plug in your AC adapter (not before, but after the "sleeping" occurs) and charge it to its full extent = 100% which is important.

After the calibration process, the reported wear level is usually higher than before. This is natural, since it now reports the true current capacity that the battery has to hold charge. Lithium Ion batteries have a limit amount of discharge cycles (generally 200 to 300 cycles) and they will retain less capacity over time.

Many people tend to think "If calibrating gives higher wear level, then it's a bad thing". This is wrong, the calibration is meant to have your battery report the true capacity it can hold, and it's meant to avoid surprises like, for example, being in the middle of a presentation and suddenly the computer shuts down at 30% of charge.

PROLONGED STORAGE

To store a battery for long periods of time, its charge capacity should be around 40% and it should be stored in a place as fresh and dry as possible. A fridge can be used (0ºC - 10ºC), but only if the battery stays isolated from any humidity.

One must say again that the battery's worst enemy is the heat, so leaving the laptop in the car in a hot summer day is half way to kill the battery.

PURCHASING A REPLACEMENT BATTERY

If you intend to purchase another battery, it's recommended that you do it only when the current battery is much degraded. If it's not the case, the non-usage of a battery leads to its degradation.

If a spare battery is purchased and won't be used for a long time, the above storage method should be used. Besides that, when purchasing a battery you must pay attention to the manufacturing date.

CONCLUSION

There are a number of precautions to take to ensure safe and practical function of the laptop battery. Some laptop batteries can become overheated from charging which can create a fire hazard. It is important to place the laptop battery in a location that is free of flammable objects such as paper or furnishings. In general, it is good to avoid extreme temperatures for proper optimal function of a laptop battery. Battery life of a laptop battery depends greatly on how the laptop is used. A laptop battery will not last very long without being charged. A useful method to extend battery life is to close as many unnecessary programs as possible. By closing programs that will not be needed will save useful battery life.

These are just a few pieces of information about laptop batteries that will help the user understand how to care for laptop batteries and how to manage laptop battery life. There is much more information about laptop batteries, including battery construction, battery charging and much more.