Ok - the Kings 35L lasted 76 hours at 2C in the office with temps between 16-24C, which is not too challenging but still good performance. Also worth noting, I went sailing recently and took the Kings along as a freezer set to -18. It did a sterling job of freezing the lamb, pies, and maintaining ice for the G&Ts, but ate a 40A LiFePo battery every 24 hours - we had 2 on the boat and cycled them - charging one whenever the motor or generator was running. My battery was thrown across the cabin off Stockton Bight in a 35 knot westerly, bounced on the dinette table (ouch) and landed on the sea berth opposite - it showed no sign of harm and worked normally when plugged back after being put under a seat where it should have been in the first place. Note there's a 100Ah Companion battery now available that weighs only 4kg more (around 10.5kg) and it offers all the same inputs and outputs, integrated handle and robust case. That's the one I would buy if it didn't cost 1400 bucks. Worth keeping an eye on it over the next couple of years - especially around Black Friday sale times.