[RhysU]

"Shouldn't" and "can't" are different things.

I can power a couple of radios with far less than a full generator.

[jtbayly]

And you need a giant generator to charge any large vehicle in a reasonable amount of time, not just a generator that can keep the electricity on in the building.

[the_mar]

what if i told you, you still need to charge ur fire truck

[RhysU]

Alternators won't do it?

[catiopatio]

The (very large) alternator will power the onboard electrical systems and charge the chassis/equipment batteries while the engine is running.

When sitting in a truck bay, there’s a shore line providing mains power to keep everything charged — we’re generally talking a 10-16A draw.

That’s easily met with a small generator, as opposed to the insane power draw a full EV battery would require.

[dan000892]

The fire apparatus I’ve worked on have a 120V inlet called a shoreline to keep equipment (MDT, radios, cardiac monitor, portable suction, and Lucas battery chargers, interior lighting, etc) operational at station without draining the battery.