2020-06-29 After operating portable on my  Miady 6Ah (76.8Wh) LIFEPO4 battery this past weekend for Field Day, this morning I recharged the Miady 6Ah (76.8Wh) LIFEPO4 battery I used for the past two days. It took 56.2Wh to fully recharge it. I'm guessing, that if I adjust that for charging inefficiency I actually used between 45 and 50 Wh in the approximately 8 hours I had the radio on. Actual transmit time was pretty low as no "conversation" lasted more than about 30 seconds, and most much less.
The Xiegu G90 I used was running at the full 20 watts output in SSB or CW. At 13.48 volts, the radio draws 0.62 amps (8.2 watts) on receive and 4.11 amps (53.3 watts) on transmit at 20w.
Conclusion? The battery is clearly a feasible power source for a day's light operating. It is worth the money in my books! 
2020-06-28 Amateur Radio Field Day for 2020 is over. The event started Saturday at 1pm central time and ended today at 1pm central time. It is Amateur Radio's largest single activity each year involving between 30 and 40 thousand US hams. The idea is to demonstrate to ourselves and others that we can communicate without power lines, flush toilets, permanent facilities, etc.!
A friend and I set up at our local Radio Control Plane flying field, a beautiful place as the photos show. We did radio from about 2pm until 5pm. Then did a cookout. A few more after, enjoyed a visit from our son, Charles and granddaughter Millie, did a few more radio contacts and turned in.
It was hot and muggy all day and less hot but supper muggy overnight! So after a breakfast of sausages and pancakes and a hand full of contacts Sunday morning we broke camp and headed home. Oh, two flying club members visited us Sunday morning to cheer us on!
Fun was had by all, which is at least 2/3 of what it is all about! I talked to 34 other ham radio stations.
For the more technically minded, Both Gary and I used xiegu G90 rigs. His antenna was a QRPGuys 40-10 EFHW and mine was the Wolf River Coils TIA Mini with 17 foot whip. Both rigs and antennas performed well. I worked CW and SSB and Gary worked PSK digital. We both were battery powered, I with a Miady 6Ah Lifepo4 battery and Gary with a deep cycle lead-acid lawn tractor battery. Gary had rigged up a power adapter so he could run both the G90 and his small tablet-like window computer off his battery.
2020-06-26 This year's Field Day has been altered by Covid-19. Many club groups have either cancelled their plans altogether, agreed to operate from home individually or at least separate or in a few cases more or less normally. I've not been part of a club for many years so the past few just two or three friends gathered at our RC plane flying field and operated. This year it looks like just two of us will be at the field. Unless our interest fades as the Saturday afternoon wears on we plan to spend the night.
We both have xiegu G90 radios and plan to operate them. Our antennas will be a variety of wire antennas. I'll report back when it's over!