We are always looking for reliable ways to power equipment in the field. Whether it’s running a radio during an event or keeping essential devices charged, portable power is a must.
At our March meeting or at the trailer training on Saturday, you may have seen a device that Dave Kaun, N9KMY, put together. It is a compact and efficient solution that allows operators to power 12V devices using common 18V tool batteries.

The Problem
Many of us have portable 18V batteries from brands like Milwaukee, DeWalt, Worx, or Ryobi sitting in our toolkits. However, these aren’t directly compatible with 12V equipment, such as radios. Dave’s solution converts the higher voltage from these batteries down to a stable 13.8V-ideal for powering communications gear.

The Solution
Dave’s design consists of a step-down DC-DC converter housed in a repurposed metal case, originally packaging for a wallet. This compact setup allows for easy transport while ensuring safe and efficient power delivery.

Key Components:
- Battery Adapter: Provides a secure connection between the battery and the circuit, offering bare wire outputs.
- On/Off Switch: Allows users to control power delivery easily.
- DC-DC Converter (DZS Elec 12A Step-Down Buck Converter): Converts 18V to a steady 13.8V output. [Available on Amazon](https://amzn.to/4kUH2Zg)
- Volt/Amp Meter: Displays real-time voltage and current readings for monitoring power usage. [Available on Amazon](https://amzn.to/41NJ9qt)
- Anderson Powerpole Connectors: Provide a reliable and standardized connection for radios and other equipment.

Putting It All Together
Dave adjusted the DC-DC converter to output 13.8V, ensuring compatibility with most amateur radio equipment. The repurposed metal case offers durability while keeping the components neatly enclosed.

Why This Matters for ARES
This field power solution offers a practical way to keep radios operational during deployments, public service events, and emergencies. With easy access to tool batteries, operators can stay powered up without relying on traditional deep-cycle batteries.

Interested in Building One?
Attached is a circuit diagram to guide you through assembling your own portable power supply.

This project is a great example of ARES ingenuity-using readily available parts to create a dependable field-ready power solution. Thanks to Dave Kaun, N9KMY, for sharing this valuable build with our group!