LiFePO₄wered/Pi3™

Powerful MPPT charger

Automatically optimizes charge current

The LiFePO₄wered/Pi3™ charger employs a Maximum Power Point Tracking (MPPT) charge controller to make the system automatically adapt to the amount of current available from the power source.

This allows the LiFePO₄wered/Pi3™ to draw a high charge current of up to 1.33 A when connected to a powerful 2 A USB charger, but not overload a less capable power source such as a PC USB port by automatically reducing the charge current.

Even better, this feature even makes it possible for the LiFePO₄wered/Pi3™ to be directly powered from a 5 – 7 V nominal solar panel!

UPS functionality

An end to corrupted SD cards

Even if you never intend to unplug your Raspberry Pi, the LiFePO₄wered/Pi3™ provides great value. How often have you had your SD card corrupted when the power failed? What if you need to keep an application running through power outages?

The LiFePO₄wered/Pi3™ has the battery capacity and charge current needed to provide UPS (uninterruptible power supply) functionality even for power hungry high performance Raspberry Pi systems. It was designed to keep a system running indefinitely if at all possible.

When external power is removed it will keep your Raspberry Pi running for a programmable number of minutes or until the battery runs out, and then perform a clean shutdown. The system can also be configured to automatically boot the Raspberry Pi whenever enough battery power is available or when the external power is restored, making it a true UPS solution.

Clean shutdown

Your Pi will always shut down before power is removed

Maybe your SD cards don't die due to power outages, but because you run a headless system and have no other choice but to yank the power cord.

No more!

Whether the Raspberry Pi is shut down by software, by the LiFePO₄wered/Pi3™ auto-shutdown feature, because the battery runs out, or because you use the handy touch button to shut it down manually, the Raspberry Pi will always be instructed to first do a proper shutdown, and only then the power will be turned off.

Touch button

Convenient boot and shutdown for headless systems

It is very common for a Raspberry Pi to be used without a screen, keyboard and mouse. Common uses are to control some device or run a service, and unless someone goes through the trouble to log in remotely and perform a shutdown, the only way to turn them off is to remove the power. There are endless reports of SD cards corrupted by doing this.

Now there is a better way! The LiFePO₄wered/Pi3™ provides a convenient touch button that can turn on the Pi and turn it back off by doing a proper shutdown first. The touch button has a press and hold feature that prevents accidental activation.

Feedback LED

Know what's going on

User friendly systems need good feedback. Especially in a headless Raspberry Pi setup, it can be hard to know what's happening to the system.

The LiFePO₄wered/Pi3™ provides a red LED to indicate the battery is charging and a green LED to indicate the power state of the system: off when the Raspberry Pi is off, on when the Raspberry Pi is on, and "breathing" when it is booting or shutting down. The LED also provides feedback when the user presses and holds the touch button and indicates if the system can't comply with the user's touch input by flashing. Once booted, the LED can even be controlled by user processes!

Wake-up timer

Extend battery life

If you have a low duty cycle application, you can greatly extend the battery life by using the LiFePO₄wered/Pi3™s wake-up timer. This feature allows an application to set the number of minutes the system will stay powered off after shutdown. When the time elapses, the LiFePO₄wered/Pi3™ will start the Raspberry Pi up again. This user settable time can range from a minute up to 45 days!

Excellent uses of the wake-up timer are low frequency data logging and time lapse photography.

Ultra low power

Less than 5 µA

When the Raspberry Pi is off, the LiFePO₄wered/Pi3™ is still working: it's scanning the touch button, keeping track of the voltages in the system and maintaining the wake-up timer. It does this using very little power, making it possible for a system to be in standby for years on a single charge.

Voltage monitor

Keeping track of battery, input and output

The LiFePO₄wered/Pi3™ takes continuous readings of the USB input, battery and Raspberry Pi voltages. The smart controller will not turn on the power if it detects the Raspberry Pi is powered from another source. It will also shut the system down and prevent it from booting when the battery voltage is too low, ensuring the battery stays in good condition. In addition the Raspberry Pi can be automatically booted when USB power is provided.

Input flexibility

More than just USB power

The LiFePO₄wered/Pi3™ makes it easy for those who want to power their Pi from something other than USB.

The bottom of the charger board provides solder pads to easily connect other input voltage sources, plus the extended input voltage range from 4.75 to 9 V makes it possible to use solar panels, wall warts, 7.2 V RC LiPo packs and many other power sources. And no need to worry if your input source is sporadic or unreliable—the LiFePO₄wered/Pi3™ can keep your Pi running through the rough spots.

Configuration tool

Application access to settings and data

The Raspberry Pi and LiFePO₄wered/Pi3™ communicate with each other using a I²C bus. A command line tool and library were created to allow users to easily access the data inside the LiFePO₄wered/Pi3™.

Using these tools, the user can access voltage measurements and thresholds, touch button parameters, the wake-up timer and auto-shutdown timer and the auto-boot settings. Some of the parameters can be written to flash to make changes permanent.