If you need a large, high-energy-density battery for a project, scooter batteries are a good source. They are typically 48V batteries with capacities of 15-18Ah which is quite a lot of power! A particular battery type is gaining popularity — the RPH0002 — which is fairly easy to find new or second-hand. However, it has an unusual connector and safely attaching to it essentially requires a bespoke board — and that’s exactly what this DIY RPH0002 Connector Board is for.
The connector comes as a kit that you need to solder together. It’s a clever design, using ENIG plated PCB for the connector pins, and adding both a fuse as well as power and data connectors. Unlike most batteries, the RPH0002 has some smarts inside. You need to communicate with it over CAN to enable power output and to keep it active. This can be easily achieved with CAN libraries or with another board by the same seller — the CANarchy control board.
Once soldered up and connected, you can power your project directly or connect a buck converter in-line to drop the voltage down to 3.3/5/12V or whatever your project needs. With the efficiency of a switching controller and the power density of these batteries, small IoT projects can last for months on a single charge while still being able to draw large bursts of high current if needed for RF amplifiers! Add a solar charging system and you’ve got a total power solution that can last even through long periods of darkness.
