Running through the FF2 with some thin mint cookies rosin at the moment. I charged both my batteries until the blue LED was solid. The last one to be on charge stayed in the vape.Concentrate mode 480f for some nice terpy low temp goodness.I am using my revised draw speed and method, only holding the heating sensors for 9 seconds maximum very very very light draw. I'll usually inhale for a second or two after letting go ot the touch sensors. I don't know how to describe the draw people say there is draw resistance but it's not in a sense of the vape restricting you rather that you have to restrict yourself. This is the only way I can use the vape and not charr my herb. I think this is an appropriate method.* MY THEORY When taking bigger pulls the heater, sensor and battery are probably going to be working overtime to compete with all the air transfer and temperature changes.I am looking at a way of measuring how hard I'm inhaling.* App was open and connected - vape heated up straight away no blinking red light. I got 14 pulls from the smallest amount. The first two pulls had 0 visible vapour but were really tasty and after the first the rosin still hadn't completely melted in to the pad. Pull 6 gave a nice cloud. It over heated at pulls 11 and 14. There didn't seem to be much left so I put the vape down and came to write this. Checked battery level - shows 3/4 fullOverheating doesn't worry me based on the above and with concentrates.Reloaded, checked app and vape was still responsive without having to reconnect. Battery still shows 3/4Round 2 was pretty much the same. Finished on 14 pulls overheated seems all gone, pull 13 was very cloudy. App Shows 1/4 full on battery.Round 3 there was a red flash around the 10 pull point but it also overheated and then proceeded to give me up to 16 pulls after that the LED lit up light blue. Then lit up solid blue like when fully charged.I just booted up the app (android) and received a firmware update? 3.27?Battery Shows Red. The vape was quite hot during the 3rd session.These sessions were done quite close together. Within the space of an hour so there is probably some residual heat in there. I'm at 100% calibration.I tried to get another pull out of it about 10 minutes later. Got the empty battery LED = 44 pulls off first battery.Battery 2 -S1- Took 10 pulls, left it for 5/10 minutes. Got another 8 pulls before overheating. Battery level shows 3/4 full.S2- 14 Pulls - Battery shows half full.Going for food.Came back an hour later. Blinking red LED. App shows battery 1/4 fullI got it working again by taking the battery out twice, I also held the side sensors for a few seconds but didn't let it fully warm up fully. Two blinks of LED (green) - Twice without removing battery then on the 3rd time it heated up and gave me 18 pulls before giving me the flashing red lights again 19th pull incomplete.Sorry this is long and a sort of hit by hit account: I just feel like it could provide useful details - how come my unit updated? I can't remember my previous version number. Received a week ago. It updated when I first synced the vape to the app. I wouldn't expect them to be working on apps if they're releasing a new version? Could be wrong.Then the reseating and 'prep' on the battery?? Could that help. Then again there are faulty batteries out there. I think I've just convinced myself that mine are working fine. The vape definitely works as expected. I guess everyone will have their own technique and preference. @terrptastin station - hope this helps. Just thought it would be handy considering we got them at pretty much the same time which is why I did concentrate @ 480 F.All the best.