External Power Sources

ARES/RACES stations generally run from external power when it’s available. Batteries have limited capacity and should be kept in reserve (or recharged) when external power is available.

Utility/Building Power

Convert the supplied 120 volt AC power to the required 12 volt DC power using a switching power supply sized large enough to support all of the station equipment.

Never depend on utility power; always have battery backup. Utility power outages are common, especially during the emergencies that we respond to. Even in a building with backup power, our stations need to run while the generator is being started or refueled.

Vehicle Power

Most vehicles have one or more ANSI/SAE J563 (“cigarette lighter”) power sockets, which provide nominal 12 volt DC power, usually fused at 10 or 20 amps. The standard Go Kit includes a cigarette lighter plug.

Never depend on vehicle power; always have battery backup.

• There may not be an unused socket available.
• If the vehicle isn’t running, you don’t want to drain its battery.
• The vehicle voltage may be too far out of range for the radio. (Although vehicles nominally provide 12 volts, in practice they can range from 9 to 16 volts.)

Generators

Gas or propane generators can provide 120 volt AC power, and sometimes 12 volt DC power. However:

• They’re noisy and messy.
• They can only be used outside.
• They need fuel and maintenance.
• They are restricted or prohibited in some locations.

If you use a generator, make sure you:

• Always comply with any local restrictions.
• Always use it outside in a well-ventilated area.
• Always have a working fire extinguisher nearby (but not too close).
• Always place the generator on a drip pan to catch leaks.

Never depend on a generator; always have battery backup. Generators are prone to failures, and will eventually run out of fuel.