so we have a county-level ARES exercise coming up in about three weeks and im trying to nail down the power situation before then. last time we did one of these i ended up borrowing a honda eu2200i from a club member and it worked fine but i felt like i was just winging it the whole day and i'd rather actually have a plan this time.

our setup is going to be a IC-7300 for HF and a couple of Kenwood TM-V71As on VHF/UHF, plus a raspberry pi running winlink and probably a laptop for ics-213 stuff. rough estimate puts me somewhere around 30-35 amps average draw if the HF rig is transmitting at maybe 60% duty cycle, which honestly is probably conservative for how these exercises go.

my question is whether i should just commit to a dedicated generator setup or if a good LiFePO4 battery bank could handle a 6-8 hour exercise without a recharge. ive been looking at the bioenno 100ah 12v batteries and theoretically the math works out but theory and a parking lot in july are two different things. also the antenna situation — we have a resonant dipole cut for 40m that i can throw up pretty quick but im debating whether to bring a buddipole as a backup or if thats just extra weight. parking lot deployments are annoying for radials and ground planes if we end up on VHF simplex with a vertical.

anybody done extended field operations and have opinions on the generator vs battery debate for this kind of load? not trying to run a full EOC out of my car, just solid portable ops for most of a day.

the bioenno 100ah will probably get you through it depending on your actual duty cycle. i ran a similar setup last summer — ic-7300 plus some accessory stuff — off a 100ah lifepo4 and made it about 7 hours before i started getting nervous about state of charge. that was maybe 40-50% transmit time on 20m so your mileage will definitely vary. one thing i'd say is dont skip bringing a way to monitor the battery voltage in real time, not just a coulomb counter. under load those readings can be misleading and lifepo4 has that flat discharge curve that tricks you into thinking you have more headroom than you do and then it drops off fast.

on the antenna question, honestly the buddipole is great but for a parking lot ARES exercise where 40m is your main band i'd just stick with the dipole. you know it works, you know how to put it up, and the buddipole takes longer to tune than people admit especially if you're trying to move bands in a hurry. bring the buddipole if you think you'll need 20m or 15m coverage and want flexibility, otherwise its just more gear to trip over.

generator every time for a full day exercise, at least as backup. batteries are great and i love my lifepo4 setup but theres always something that draws more than you planned — someone plugs in a fan, you end up running the laptop charger the whole time, duty cycle ends up higher because the net control keeps asking for traffic, whatever. the eu2200i you mentioned is honestly one of the better choices for this, quiet enough that you wont drive everyone nuts and the inverter output is clean enough for the radios. if you can borrow it again i would.

that said i usually run battery primary with the generator as a backup charger rather than running the genny all day. keeps the noise down and your fuel consumption way lower. just set the generator to kick in when battery hits like 50% SOC and let it top off while you keep operating. takes a little setup but its worth it for anything over 4-5 hours.

also for the VHF vertical and radials issue — if youre in a parking lot just lay 4 radials flat on the asphalt. not ideal but works fine for a simplex net, ive done it plenty of times. you lose maybe a db or two over elevated radials, nobody will notice on local VHF.