Engineer Pascal Herczog has put together a Raspberry Pi accessory designed to offer reliable battery power for Raspberry Pi projects without bulking out the footprint: the Red Reactor.
"If you love building gadgets, you’ll know that the Raspberry Pi and similar single board computers are amazingly versatile for portable designs like radios, gaming consoles, remote monitoring systems, right up to fully featured PCs and media servers," Herczog explains.
"But where other battery power solutions simply fail to deliver on the key requirements, the Red Reactor provides everything you need for a robust, powerful and easy to integrate battery power supply!"
Designed to sit underneath a Raspberry Pi single-board computer and connecting via pogo pins to avoid the need for soldering, the Red Reactor keeps the 40-pin general-purpose input/output (GPIO) header free for other hardware. The rear of the board includes a holder for a pair of lithium-ion 18650-format battery cells, and can run with only one fitted — while two, naturally, doubles the run-time from a single charge.
The board includes full battery protection with over-charge, over-discharge, and over-current protection, a seamless switchover from external to battery power, and an I2C bus for querying battery voltage, charge/discharge current flow, and the presence or absence of external power.
For headless operation, the board also includes a connector for an external button with long- and short-press detection on interrupt — providing safe-shutdown support with suitable software plus a software-independent reset on extra-long-press. There's also a V output designed for high-current external hardware, suitable for "high, peaky load."
"The Red Reactor Pi-Battery Widget installs on your [Raspberry] Pi OS Desktop with a few simple steps," Herczog notes of the software provided with the board. "Simply configure your battery capacity and it will model both charge and discharge times, show voltage and current, provide a low battery warning and automatically force a safe shutdown when necessary.
"The Red Reactor Remote Monitoring application server means you can remotely monitor everything you need to know about your battery simply via a web browser on your PC, phone, or tablet. Monitor voltage, current, charging, battery status, CPU temperature and throttling conditions, all with dynamically configurable plots."
Herczog is funding production of the Red Reactor through a Kickstarter crowdfunding campaign, with physical rewards starting at £30 (around $35) for early-bird backers. All hardware is expected to ship in January 2023.