so our ARES group has a county-wide exercise coming up and im putting together a portable station for the first time on my own without just riding along with someone elses gear. ive been doing this for a few years but always just showed up and plugged into whatever was already running so actually sourcing and setting up my own kit is new territory for me.

the plan is to run an IC-7300 as the primary HF rig, maybe a 2m/70cm mobile unit for local nets, and i need to keep everything going for potentially 8-10 hours. the exercise site has a parking lot and a small shelter but no shore power, so its either generator or battery and ive been going back and forth on this for a while.

for antennas i was thinking an end-fed halfwave on a 31ft jackite pole for HF and just a mag mount on the car for VHF/UHF. the EFHW with a decent tuner should cover 40 through 10 okay i think. my main hangup is the power side — a small Honda 2200i runs clean enough for the radios but its another thing to haul, needs fuel, makes noise which the served agency isnt thrilled about. on the other hand a 100ah lithium battery is expensive and i dont totally trust my math on how long it would actually last under real operating conditions.

anyone run similar setups for extended exercises? curious how people handle the generator vs battery tradeoff when you actually need the station to stay up reliably

the math on the lithium isnt as scary as it seems once you actually sit down with it. a 7300 on SSB is pulling maybe 2-3 amps on receive, spikes to maybe 20-22A on transmit at full power but you wont be keying down constantly. if your typical duty cycle is like 20-25% transmit you're probably averaging somewhere around 5-7A depending on how you run it. 100ah lithium at that rate, you're looking at somewhere in the 12-15 hour range comfortably, and lithiums hold voltage way better than AGM so the radio wont start acting weird as the battery drains down.

i'd honestly lean battery for an 8-10 hour exercise, especially if noise is a concern. a 2200i is great but even those "quiet" generators are noticeable in a parking lot and if the served agency is already making noise about it, thats a headache you dont need during an eval. bring a small solar panel if you want a backup top-up option. the generator is my fallback for multi-day activations, not single day stuff.

the EFHW on a jackite is a solid plan, just watch your feedline routing if you're operating from a vehicle nearby, i got some nasty RF in the shack once running that configuration until i figured out my counterpoise situation.

yeah what he said about the lithium math is pretty much right. one thing i'd add — if you do go battery, dont just assume 100ah means 100ah usable. most manufacturers spec them at like a 20-hour discharge rate so if you're pulling harder than that you're not getting the full rated capacity. lithium is way better than lead acid in this regard but still worth knowing.

personally i run a 50ah lithium with a 100w panel and a cheap PWM controller and it keeps up fine for a full day of light to moderate operating. wouldnt trust it for continuous high-power digital work but for voice emcomm stuff its been totally fine. generator stays in the truck as a just-in-case.