Measuring the Charging and Discharging Speed of Your Android Phone

If you’ve noticed that your smartphone’s battery life isn’t living up to expectations, or if you’re seeking to assess the performance of a charger, measuring the charge and discharge rates can provide valuable insights. In this guide, we will explore when and how you can effectively measure the charging and discharging speeds of your Android device using free tools.

Importance of Measuring Battery Charge and Discharge Rates

While Android devices come equipped with a basic battery tracker that portrays overall charging speed and battery drainage, there are specific scenarios where precise measurements—in milliamperes (mA)—become essential. Here are some compelling reasons to measure these rates:

Identifying the optimal charger or cable for your device can be done by evaluating the charging speed in mA. Simply test various chargers and cables to determine which performs best.
Monitoring charging patterns at varying battery levels allows you to verify that both your phone and charger function correctly, especially from low to full charge.
Detecting irregular charging behavior can help identify issues, like sudden drops in charging speed.
The built-in battery estimate is often based on historical usage patterns, leading to inaccuracies during unexpected activities. Measuring battery drain during specific tasks, such as gaming, results in a more precise estimation of remaining usage time.
You can pinpoint battery drainage caused by individual apps without continuously running them, enabling immediate action to stop excessive consumption.
Assessing the impact of battery-saving strategies, like altering screen brightness or limiting background activity, provides insights into which methods yield the best results.
Monitoring sudden changes in discharge rates can act as an alert for potential hardware malfunctions.

Tracking Charge and Discharge Rates with Ampere

To accurately assess charge and discharge speeds, utilizing a dedicated app is recommended. While these apps draw data from your phone’s Battery Management System (BMS) and may not account for various internal inefficiencies, they are generally sufficient for everyday monitoring.

We suggest using the free Ampere app. It boasts a user-friendly interface and presents the critical information necessary for your assessments. Before launching the app, ensure your phone’s battery is in the desired state for measurement; for instance, if you’re interested in determining peak charging speed, start with a battery level below 20%.

Once you open the app, allow it 15 to 20 seconds to stabilize the readings. Keep an eye on the display—orange readings indicate discharging, while green denotes charging.

Ampere App showing battery current measurements

The most significant measurements to focus on are the current (in milliamperes) and the voltage.

Interpreting the Data

To grasp the implications of the measurements, conversion of these values may be necessary. For instance, if you’re evaluating a charger’s wattage, you’ll need to convert the current in mA to watts. Here’s how to do it:

Converting mA to Watts

To change milliamperes into watts:

1. Divide mA by 1000 to convert to amperes (A).

2. Multiply the resulting amperes by the voltage. Using an example:

2850 mA ÷ 1000 = 2.850 A

2.850 A × 3.961 V = 11.29 W

This means the battery is currently receiving 11.29 W, significantly lower than the advertised 33W capacity. This discrepancy can be attributed to various factors, including conversion losses, the operational draw of the phone, and the negotiation between the battery and charger, particularly when the battery is at 36% capacity.

Converting mA to Percentage Loss per Hour

If you wish to understand how much battery percentage you could lose per hour at a specific discharge rate, follow these steps:

350 mA ÷ 5500 mAh × 100 = 6.36% per hour.

In general, when measuring charging speeds using the app, expect observed numbers to range from 60% to 75% of the optimal capacity indicated by the charger, especially under ideal conditions when the battery is critically low.

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