Ampere v2.11

Have you ever experienced a noticeable difference in charging speed when using different charger/USB cable sets? Now you can put this to the test with Ampere.

Ampere allows you to measure the charging and discharging current of your battery.

PRO features include:

• Widgets
• Notification
• Alerts on device
• Alerts on Android Wear

Please note that not all devices are supported due to the lack of an appropriate measurement chip or interface. You can find a list of unsupported phones at the end of the app description.

Please be aware that Ampere is not intended to be perfectly accurate in terms of milliamp (mA) measurements. Its main purpose is to help you evaluate which charger/USB cable combination works best for your device.

Please make sure to also read the FAQ: http://goo.gl/R8XgXX

To use Ampere, simply start the app and wait for approximately 10 seconds until the "measuring" message appears. It will then show you the charging or discharging current.

The current reading can be influenced by various factors such as the charger type (USB/AC/Wireless), the USB cable, phone type, current running tasks, display brightness, WiFi and GPS states.

While the measurements provided by Ampere may not be scientifically precise, they are sufficient for relative comparisons between different chargers and USB cables on the same device.

If Ampere constantly shows a reading of 0mA, please go to the settings and select the "Old measurement method" option. This will force the app to revert to the old measurement interface, if available on your Lollipop device.

However, please note that certain Samsung devices do not provide accurate measured values (e.g. S5), but rather display the maximum possible charging current based on the USB cable/charger configuration. This is a firmware issue.

Background info: Ampere measures the charging/discharging current of the battery. When your phone is not connected to a charger, the app will display the discharging current as a negative value. When a charger is connected, the current provided by the charger is used to power your phone and charge the battery with any remaining power.

For example, if your phone consumes 300mA without a charger connected (-300mA displayed), a 500mA charger will charge your battery with a maximum current of 200mA (200mA displayed).

Technical info: The displayed current value is an average derived from 50 measurements, excluding the 10 highest and lowest values. The displayed current may fluctuate or even reach zero due to unstable values provided by the Android system. Different companies use different battery types and other hardware, which makes it difficult to obtain accurate results for charger compatibility.

Please be aware that LiPo batteries do not draw the maximum charging current for the entire duration of the charging process. As the battery level approaches full charge, the charging current will decrease.

If you'd like more information on LiPo charge stages, you can refer to this graph: http://batteryuniversity.com/_img/content/ion1.jpg

You can also check out Dave's (EEVBlog) LiPo Charging Tutorial: http://youtu.be/A6mKd5_-abk

Phones/ROMS that are compatible only with the "Old measurement method" enabled and the correct "Measurement interface" selected:

• HTC One M7 / M8
• LG G3

Phones/ROMS reported to be not working with this app:

• Galaxy Grand Prime - fortuna3gdtv
• Galaxy Note2 - t03g, t03gchn, t03gchnduos, t03gcmcc, t03gctc, t03gcuduos
• Galaxy S3 - d2att, d2spr, d2vmu
• Galaxy Tab4 7.0 - degas3g
• HTC Desire 510 - htc_a11ul8x26
• HTC One S (ville), X (endeavoru), XL (evita)
• HTC Sensation 4G - pyramid

Please do not rate the app poorly if your phone is listed above. The issue lies with your phone's lack of support for this type of measurement, not with the app itself.

If Ampere does not work on your device with a pre-Lollipop Android version, please read the first and second posts in this XDA developer forum thread: http://goo.gl/pZqJg8. Make sure to include screenshots of your problem when posting in the XDA thread.

Please make sure to also read the FAQ: http://goo.gl/R8XgXX