Glossary

Technical terms

Battery capacity

The maximum amount of energy that a battery can store when fully charged. The capacity of a battery deteriorates (i.e., degrades) with use. It is related to battery health in the sense that the capacity of a healthy battery (for example a new battery) is close to the capacity claimed by the manufacturer. For example, a new battery may be able to store 2200 mAh. After a year of use, it may be able to store only 1800 mAh.

Battery charge controller

Piece of electronics (integrated circuit / chip) present in the device (e.g. phone, tablet) that regulates the charging and discharging of the battery. AccuBattery uses information provided by this module to track power usage and charging currents.

Battery health / battery lifespan

Battery lifespan (or battery health) is the amount of time a battery lasts until it needs to be replaced. Note that this is substantially different from battery life, which indicates how long the battery lasts until it needs to be recharged. When the battery lifespan runs out, the battery can no longer store enough energy to be useful, even after charging.

Battery usage / power usage

Battery usage (or power usage) is a measure of energy consumption. It may indicate either the speed at which the battery is drained, or a total amount of energy used.

Battery wear

An indication of the amount of “damage” that a battery sustains. When a battery is charged over and over again, it eventually cannot store as much energy as it originally could. As such, its “health” has deteriorated due to the “damage” it sustained. We call this “wear”, as in “to wear out” or “wear and tear”.

Charge alarm

An alarm to remind the user to disconnect the charger when the battery reaches a given level. The wear sustained by a battery during a charge session decreases drastically when the battery is not charged to 100% of its capacity. This feature allows the user to set a percentage (e.g. 80%) at which they would like to be reminded (notification + ringtone) to disconnect the charger.

Charging current

A measure of the speed at which a battery charges. For phones, this is usually expressed in the milliampere-hour unit. Note that this is not a measure of energy, but rather how fast energy is transferred. For example, if a battery charges at a speed of 800 mA for 1 hour, its total charge will have increased by [1 hour × 800 mA] = 800 mAh. Conversely, if it charges for 1 hour and 30 minutes at a rate of 800 mA, its total charge will increase by [1.5 hours × 800 mA] = 1200 mAh.

CPU

Central Processing Unit, aka processor. The electronic circuitry within an electronic device that carries out the instructions of a program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions.

Deep sleep

An Android device will often activate an ultra-low-power mode while the screen is turned off to minimize power usage. This mode is called deep sleep. Note that this is not the same as standby. An Android device is often said to be in standby while the screen is off. However, it is not necessarily in deep sleep while the screen is off. Also, please do not confuse this with the doze feature introduced in Android M 6.0, which can be configured by the user. The deep sleep mode is regulated by Android itself and is not user-configurable as such.

Unit: mAh (milliampere-hour)

The milliampere-hour is a unit that is frequently used to indicate battery capacity. For example, a manufacturer may claim that a battery has a capacity of 2200 mAh. Please translate to the equivalent abbreviation in your language. If you are unsure, use “mAh”.