so we have a county-wide ARES exercise coming up in about 5 weeks and im trying to nail down the power situation before i commit to hauling everything out. last time we ran the exercise we had a little honda eu2200i running the whole station and it worked fine but it was honestly overkill and the fuel thing got annoying after about 6 hours. trying to decide if its worth switching to a battery-based setup this time around.

the load is pretty modest — IC-7300 running at maybe 50-60 watts output most of the time, a small laptop, and a signalink for digital modes. maybe a couple LED lights. i ran some rough numbers and figured maybe 20-25 amp hours per hour at that draw, which would put me right around 100ah for a 4-5 hour operational period. i have two 100ah lifepo4 batteries from a previous project so that would cover it if my math is right but id love a sanity check from someone who's actually done this kind of thing.

for antennas i was planning on a Wolf River Coils silver bullet with a tripod mount and a 17ft whip. decent performer on 40 and 20 which is where most of our nets will be. dont really need anything crazy but im open to suggestions if something works better for portable NVIS on 40.

your math is a little optimistic honestly. the 7300 at 50-60w out is pulling more like 18-20A on transmit from a 13.8v supply, and even if your duty cycle is low you gotta factor in the laptop and accessories. i usually plan for about 25-30Ah per operational hour for a similar setup just to have headroom. two 100ah lifepo4 in parallel gets you there for a 4-5 hour op but not with much to spare — i wouldnt feel totally comfortable without a way to top them off or a backup plan.

that said if its truly a 4-5 hour window and you start fully charged you're probably fine. lifepo4 has pretty flat discharge so you'll know fast if something's off. id still bring the honda just in case and leave it in the truck. on the antenna side the silver bullet works but for NVIS on 40 a simple inverted-V at 30-35 feet is gonna eat it alive if you have any way to get wire up. even a 40m dipole on a fiberglass mast would be better for close-in stuff. the coil antenna is convenient but you give up a lot.

we did almost the exact same thing at our last SET. ran two 100ah battleborn batteries and a 7300 for about 6 hours with a signalink and had maybe 30-35% left at the end so your plan is workable. we were probably lighter on the laptop draw though, had a pi running fldigi instead of a full laptop which helped.

one thing i'd add — if you're going the battery route get a clamp meter on there early so you actually know what you're pulling. we estimated going in and were pretty close but it was nice to confirm. also make sure your connectors and wiring can handle the load, we had a powerpole connection get warm on us which was a little exciting.