In article ,
James Barrett wrote:

Would it be safe to connect my HT directly to a 12v car battery? If the
HT will only draw the amperage it needs, and the voltage is within the
specs, it should be safe, right?

Maybe yes, maybe no.

Some HTs require _less_ than 12 volts, and will be damaged by the
higher voltage. This should be clear in the manual.

A car's electrical system as a whole is a less safe thing to connect
an HT to than an isolated car battery, if the vehicle is being
operated. A vehicle's voltage distribution system is subject to
voltage spikes and surges (in particular, due to a phenomenon called
"load dump" e.g. turning the lights off while the engine is running).
Car electronics usually requires that the device be able to withstand
a load-dump spike of up to 50 volts. Many HTs won't survive this.

The manufacturer-recommended "plug into cigarette-lighter outlet"
adapters for HTs often include some filtering and spike suppression
circuitry.

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
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