For the curious, I tried out the Biolite on the patio last night. I had a bunch of dry twigs to thumb size pieces of wood, and broke them up into 3" - 4" pieces. I light one kitchen match, allowed it to burn upwards a second and then dropped into the stove. The match fell clear to the bottom but caught the tinder right away. I had been concerned about lighting it to be honest. I know the wood won't be that dry in the Smokies, but it was amazingly simple and I didn't need to use the "crutches" of UCO matches or fire starters.
Once I had some small twigs on fire, I turned on the fan (running on internal battery), waited 30 seconds and pushed the button again to switch the fan into to the high speed (powered by the TEC unit). About 2 minutes later the LED above the USB port turned green - its internal battery was recharged and could now recharge other devices. I could hear the fire "whoosh" and saw the wood gas catching fire right at the air openings on the sides - the fire was burning hot and fast. Next time I will test boil times, but for last night's test I wanted to figure out how much juice was provided by the USB port. One thing the testing also revealed was that the stove also will be a good way to create/obtain hot embers to assist in building a larger campfire when dealing with the typical rainforest wood of the area - it was amazingly simple to light.
The "bonus feature" of charging ability was admittedly of concern to me - the documentation states 2 watts at 5 volts continuous and 4 watts peak. Someone else figured out for me that it should be about 400 MA if it indeed is putting out 2 Watts. While test burning last night, I cut apart a spare USB cable and used my DMM on the leads to verify it was indeed putting out 400 MA - and continuously. I didn't see it vary much above that and it got nowhere near the peak, however it didn't drop below that 400 mah at all. Unless I used my DMM wrong, which is possible, it stayed very stable at the rated 2 Watts continuous.
That 400 MA is slower than most "wall wart" home chargers, but faster than typical "car chargers" - it will get er done. It would take ~ 3-4 hours to fully charge a smartphone if you completely depleted your battery - however you don't need a full charge to make an emergency call or use the phone as a GPS. If you just "top off" your various electronics each time you boil water (3 cookfires a day), they should stay usable for when you need them.
I wanted to get a relatively exact MAH rating because I am also ordering a charging device that some thru-hikers attach to solar panels in order to recharge (rechargeable) Lithium cells. My SteriPen uses 16340 cells, and my flashlight uses 18650 cells. At one point and time I also used a 16340 flashlight, but I just like the 18650s better. The charging device is called a "cottonpicker
", and it is very tiny and light. The guy who makes these cottonpickers will custom set the charge rate for you on a single mode, but he also offers fancier multimode models with attached VMs. Since I know the stove will rarely put out more than 400 MA, I now know to request the single mode 480 MAH cottonpicker. This charge rate is not too fast to be safe for the smaller cells (16340) but can still charge the larger 18650 cells for a typical evening's flashlight usage pretty quickly.
The more I think about this stove the more I love it. The 2 pounds seemed egregious at first - however now I know I will be carrying fewer spare batteries, and more importantly no costly and heavy fuel canisters. The canisters that contain 4 ounces of fuel weigh 8 ounces. For most trips I would carry up two partials and one virgin canister - an $18 investment and somewhere between 16 and 24 ounces of fuel and canister weight. The 33 ounce biolite doesn't seem so heavy anymore.
If there are any more specifics those of you who wanted a review want to ask, let me know..