NEW BATTERIES
Those who actually read their Quick-Start Guide or Owner’s Manual when they get a new laptop computer may have noticed a reference to conditioning
the battery before regular use. The directions for battery conditioning
may look something like this:
To make sure your laptop battery can receive a full charge and get maximum lifespan, use the following procedure before normal use of your new laptop…
- Insert battery in laptop. Without turning it on, fully charge the battery.
- Turn on the laptop and use it until the battery is fully discharged.
- Plug the laptop into the charger and fully charge the battery again.
Repeat this procedure a minimum of three times.
There is only one problem with all this, it is not true. Well, not exactly anyway. So why do laptop manufacturers tell you to do this? (Spoiler: They need to rename it Battery Calibration)
THE OLDEN DAYS OF BATTERIES
For those old enough to remember, Ni-Cad (Nickle-Cadmium) rechargeable batteries had what was called “memory.” If you did not completely discharge the battery before recharging it, the battery would no longer be able to hold a full charge.
THESE DAYS
Laptop’s use Li-ion (Lithium Ion) batteries, and they do not have “memory” the way Ni-Cad batteries did. In fact, if you always completely discharge a Li-ion battery before recharging it you won’t get the maximum lifespan out of the battery. Not allowing the battery to completely discharge will actually increase the lifespan of your Li-ion battery!
As an example, let’s say a Li-ion battery is rated for a maximum of 500 charge/discharge cycles if you completely discharge the battery between charges. Now let’s say you only allow the battery to discharge 50% before recharging it. If Li-ion had a “memory,” you would expect the battery not to fully charge and have its lifespan reduced below 500. If Li-ion had no memory, we would expect at least 1000 charge/discharge cycles if we always recharged it at 50%. But tests show that Li-ion batteries will last 1500 charge/discharge cycles if recharged at the 50% discharge level! You can read more about how this works by clicking here.
THE REAL STORY
The “Battery Conditioning” procedure similar to the one shown above should really be renamed “Battery Calibration.” Laptop Li-ion batteries contain electronics that tell the operating system what the charge level is for the battery. This gives you the battery charge level indicator on your screen. In order for that reading to be accurate, the electronic circuit in the battery needs an idea of what the highest and lowest levels are. This is the only good reason to fully charge and discharge a Li-ion battery; to recalibrate the battery level indicator. It should be done once for a new battery. You can repeat the procedure if you have some reason to believe the charge level indicator is not accurate (e.g. your laptop shuts off before you get a low battery warning).
HOW TO DO IT RIGHT
The following procedure will help you get the most out of your laptop’s battery:
- Do not allow the battery to get lower than 50% on a regular basis.
- Keep your laptop out of extreme heat and cold. Do not leave it in direct sunlight or cold environments for long periods of time (e.g. in your car’s trunk or on the seat or dashboard, do not put it in your checked luggage on a plane).
- Configure your laptop to dim the screen and keyboard lights as quickly as you are comfortable with.
- Use a simple black screen screen-saver that starts after a short period of keyboard/mouse inactivity will reduce power consumption and extend battery life.
- Keep the number of background programs running simultaneously to a minimum since these can add additional power demands on your laptop and drain the battery faster.
- Remove unneeded devices, such as memory sticks, external sound cards, and headphones.
LAPTOP BATTERY SAVER FEATURE
Recent laptop models offer a battery saver feature. This prevents the battery from charging over a preset level; somewhere between 50% and 80% of full charge. In effect, this tries to extend battery life by coming at it from the low end of the battery charge range rather than the high end. With this feature, you charge to the preset limit, then operate off battery until it is fully discharged. This may extended battery life the same way as keeping the battery withing the 50% to 100% range; by limiting the charge/discharge range of the battery to the 0% to 50% range.