What is the Pi18650 DUAL BATTERY HAT

The Pi18650 is an add on HAT which plugs into the 40 pin connector on the Raspberry Pi. This HAT allows you to operate your Raspberry Pi without a power cable and can use various capacity 18650 Lithium Ion batteries. On board are two battery charging circuits for charging the batteries individually. The Pi18650 board also includes a 4x2 100mil header for use with a ESP8266 (ESP-01) wifi module for remote monitoring and CLOUD integration or a custom designed board. How Long Can The Pi Last? As an example the Raspberry Pi Zero uses approximately 87mA without and 103mA with a USB dongle plugged in. With a fully charged single 3000mAh battery, the Pi would last 34.5 Hrs with nothing attached. Using two batteries would double the run time.

The Pi18650 DUAL BATTERY HAT has additional features added to the single battery version. As with two batteries the design becomes more complex and we have added an LED indicator to show the battery has power and connected to the load. A comparator circuit monitors the battery voltage level and when it gets too low it will be automatically cut off from the load with a small current drain on the battery giving it longer standby time before being recharged or replaced. The batteries can be swapped on the fly by the user.

How it works?

The Pi18650 DUAL BATTERY HAT holds two single cell lithium Ion 18650 form factor batteries which must have integrated battery protection circuits for safety. The boost circuit maintains the voltage to the Pi at 5.1V for battery voltages of 3.7V to 4.2V. The jumper allows you to disable power to the Pi and Isolate the battery circuit or start the Pi. This jumper can be used with an external relay providing automatic control from circuit or system. It also includes two charging IC's which can charge at 200mA from the USB Micro connector and a battery monitoring IC which communicates to the Pi via I2C. We have coded a Python script using I2C SMBUS for you to read the battery status along with a shutdown script for low battery voltage. Charging LEDs show the status of the charging process. The Pi18650 DUAL BATTERY HAT can also be used with other development and SBC boards. Any DC power supply, adaptor or solar panel up to 18V max can be used with the charger. Use a good quality USB Micro cable as we found the flat style thinner cables did not work well with the charger and current was limited. The thicker round USB Micro cables work well.

Ensure to follow battery manufacturer or supplier safety guidelines when working with lithium Ion batteries. Batteries Not Included.

STAT1 (ON)

STAT2 (OFF) - Pre-Conditioning or Fast Charge Mode

STAT2 (ON) STAT1 (OFF) - Charge Complete

PWRGD (ON) - Power Is Good For Charge

Technical Specifications

200mA Charge Current Max for each battery
Up to 6A for Raspberry Pi via Li-Ion Batteries
Up to 18V DC Input for UPS and Charging
I2C Battery Monitoring (Python Script)
DUAL 18650 Single Cell Lithium Ion Holder
40 Pin Connector for Raspberry Pi 3 
USB Micro Connector for Charging 
Jumper for Pi On/Off/Charge
Use as a UPS or with Solar Panel 
Wifi Header for ESP8266 (8 Pin) or Custom Board
Additional Micro USB connector for powering other devices
Screw Terminal for powering external boards 
A 3-Pin Jumper to Switch USB Micro and Terminal Connection
Individual Load Cutoff Circuits 
Reverse Battery Protection
Battery To Load ON LED's
Note: Only to be used with Lithium Ion 18650 Batteries with internal Protection Circuit
Note: Raspberry Pi Not Included (Battery HAT Only)