Battery Calibration

Without calibration, the battery percentage reading will be incorrect, and your device may behave oddly—shutting down suddenly even though the new battery “reads” half charged, or working for hours when the battery reads nearly dead.

What’s calibration anyway?

The fundamental problem is that there’s no reliable way to know exactly how much energy a battery holds at any given moment. (It’s an electrochemical storage system that is always changing and decaying, and never behaves exactly the same way from one charge to the next.) About the only reliable way to gauge it is to fully charge the battery, then fully discharge it and measure the difference (a.k.a. coulomb counting). Obviously, we can't do that every time we want to check the battery level, so we have to use indirect methods—storing all kinds of usage data and using that to calculate an estimated % state of charge from moment to moment. Over time, that calculation tends to drift and become less accurate. And on a brand-new battery, there’s not really any good data to work with, so the model will be way off. Calibration helps keep estimates accurate by setting new “full charge” and “full discharge” anchors in the battery management system so it doesn’t have to guess.

How to calibrate your newly installed battery?

For phones and tablets:

1. Charge it to 100%, and keep charging it for at least two more hours.
2. Use your device until it shuts off due to low battery.
3. Charge it uninterrupted to 100%.

For laptops:

1. Charge it to 100%, and keep charging it for at least two more hours.
2. Unplug your laptop and use it normally to drain the battery.
3. Save your work when you see the low battery warning.
4. Keep your laptop on until it goes to sleep due to low battery.
5. Wait at least five hours, then charge your laptop uninterrupted to 100%.