so ive been putting together a go-kit for our county ARES group and we have a deployment exercise this saturday and im trying to figure out the power situation. right now i have a 100ah LiFePO4 battery that i run my IC-7300 off of and it does fine for a few hours but we're talking about an 8+ hour activation and i honestly dont know if ill make it without recharging at some point.

the club has a Honda EU2200i they're willing to lend out but hauling that thing plus fuel plus my antenna gear is already pushing it for my truck bed. my current antenna setup is a Chameleon MPAS Lite which i love for quick deployment but i've been thinking about adding a second feedpoint so i can run NVIS on 40 for local traffic and switch to a higher angle for the linked simplex stuff we do on VHF.

anyone dealt with this trade-off before? like at what point does the generator actually make sense vs just bringing a second battery. i can charge the LiFePO4 from my truck alternator too but id rather not idle the truck for 4 hours if i can avoid it

the math on this really depends on your duty cycle more than anything. if youre doing heavy digital like JS8Call or Winlink relay you can burn through that 100ah faster than you think, especially if you're running anywhere near full power. my 7300 at 100w pulls something like 20 amps on transmit and maybe 2.5 at receive, so do the duty cycle math for however much you actually expect to be keying up.

personally for an 8 hour event id just bring a second battery and forget the generator. two 100ah lifepo4s is still way lighter than that honda plus a gas can and you dont have to deal with the noise or the fumes or making sure someone remembers to check the oil. we did a 12 hour comms exercise last spring with two of those batteries and an FT-991A and came home with 40% left. granted we werent hammering it constantly but still.

the truck alternator thing is fine in a pinch but yeah idling for hours is not great. if you go that route at least get a decent dc-dc charger like a Victron Orion so you're not just float charging through the aux port.

yeah what he said about the Victron is solid advice. i run one in my truck and it made a huge difference vs just clipping to the battery directly.

one thing i'd add -- the chameleon MPAS is great but if you're trying to do NVIS on 40 specifically you really want that antenna as low as possible, like 15-20 feet max above ground, which kind of goes against how most people deploy it. ive had better luck just throwing up a simple end fed halfwave on a 33ft radiator for 40m NVIS than messing with the MPAS in that config. cheaper to build too if you have a 49:1 unun lying around. just something to think about if coverage in the county is your main goal for the 40m portion