that makes sense in terms of the cross sectional area of the metal - but the slot is near the end of the probe anyway so not really a 'bottleneck' in the conductive pathway what might improve performance is a series of broad ridges machined into the probe like a svea riser - but that would require an extra machining process the significant change as I see it is the solid alloy probe and hotplate where the mkI had a composite copper and aluminium alloy affair it looks like the copper probe was placed in a mould and the alloy plate cast around it and that process may have given rise to variations in the thermal efficiency of the device it seems that doing away with that copper alloy interface is responsible for the apparent improvement in performance as M reports the teg cell is the same that improvement being so marked they decided they could do away with the slot I suggest that the slot was only needed in the first place in order to try and shove more heat through the join between the copper and aluminium which itself was a bottleneck in the flow of heat and possibly not a consistent one giving rise to some stoves performing better than others regardless of the above - I am having a ton of fun tinkering with the bio wotsit - it is an intriguing device - well made on the whole and potentially the most versatile 'multi fuel' stove in existance so thanks again to M for grasping the nettle and championing this stove - without his endorsement I would not have taken a serious interest in it
Hi John @presscall Thanks again for the comprehensive review and pointing out the improvements on the Biolite 2. I just love the way you like to disassemble everything and investigate the functions inside, for our amusement and benefit. It seems they manage to resolve the initial design and functional issues and this version is much more ready for field use. I'm not a great fan of electronic gadgets when it comes for camp/outdoor cooking and never considered to charge my phone while I'm out in the woods (especially as it is switched off usually) but with this one a usefull option popped to my mind. On a longer - several days tracks or kayak trips - I was struggling to keep my GPS alive. Either we just used for location identification or searching specific points, I was not able to use it for full tracking, mapping etc, due to limited battery life. With Biolite 2 it might be possible to charge GPS directly or a larger power bank and keep it running for several days. Could you tell us what is the actual charging capability of the Biolite 2 and how long does it take to charge a largish 10000-20000 mAh power bank? Thanks Zoltan
that's a good question - M will be along with an answer soon in the mean time I got the goo that'll fix it!
I just got a few Anker portable batteries for just that purpose. 5,000, 10,000, & 20,100. Anker website about the 20,100 mAh: https://www.anker.com/products/variant/powercore-20100/A1271012 Anker website about the 10,000 mAh: https://www.anker.com/store/powercore-10000/A1263011 My only real complaint about the Biolite stove has been the concept of using a stove to charge electronic devices. I could not see using a stove long enough to make any difference. I also had trouble getting the MK I device to actually charge after I refilled the stove with wood after it burned down. Now, after John has written a few fine threads about the vast improvements of the stove applied to the MK II version, I have one on the way. (Friday arrival ETA) But, I still do not see that there will be many times when the stove will run long enough to fill a large device. (Sitting around at the Newark Meet seemed to be one of those times) I also purchased a 5,000 mAh device for hiking. I will try that the next camping trip to see how well it works, and how well it charges. https://www.anker.com/products/variant/powercore-5000/A1109011
@SomiZ It depends how hot you run the stove generally. As John has described with the Mk I fully loaded continously for a few hours managed to charge a phone. Empirical comparison with identical fuel fuel loading would be the only way I can think of to give real world comparisons. At a guess at this point for a meaningful 20000mAh charge would require a similar time scale and sitting there feeding the flames. Put it this way I don't think you'll do it making dinner. The integral battery is now larger, (18650 3000mAh) which you can utilise at a push. I'm not.sure whether John has cycled the battery from flat to fully charged to give an idea of charge rate. Not sure that helps but food for thought. Go on buy one, you know you want to.
@snwcmpr You'll have to bring yours over next year. Excellent comments Ken, crossed postings. A reason I bought the solar charger, it'll do a job even when you're not eating.
Most of the reviews I'm seeing show people sitting around the Biolite campfire style, not necessarily just cooking. If the fuel is free, doesn't need to be hauled in, and the flame is pleasant, why not gather round and enjoy? Fire it up, make some tea and soup for a mid day meal, then get on the road again for sure, but at night when settled in camp, why not take the time? I remember seeing an advertisement here on CCS that specifically showed people gathering around watching the fire, nothing cooking at the time.
According to the Biolite website specification for the Campstove 2 the peak TEG output is 3 watts with 10 watt (5V, 2A) output possible from its charged 2600mAh battery. I interpret that as maintaining a 3 watt output on a hot fire for as long as it’s stoked with fuel. More drain than that and the fan remains powered but the battery depletes. So, something over 3 hours at 3 watts to charge a 10000 mAh power bank, or an hour if you’re prepared to have the Biolite battery deplete. Very good point, and as @Simes has said, it was a pleasant way to accompany the talk and good company at our Newark gathering - plus Simon and Sarah’s pizzas and Wim and Roland’s beers! John
I had a device like this about ten years ago - another way to use your lunch to charge a phone as I recall it worked ok and I lost it somewhere - £2 from china I will get another then again a bit of wood smoke repels mosquitos
If I'm doing the math right, 3w at 5v is 600mA, which would take on the side of ~17 hours to charge a completely depleted 10,000mAh battery. In actuality, longer than that, as the fan has to be powered as well. Or am I off base?
Thanks for all the good feedback and the points. I think Marc pointed out a good limitation, to charge a 10000 mAh from flat requires lot of campfire time (and I not want to extrapolate to a 20000 mAh one). The situation I can think of a good use are in longer expedition - like a 2 weeks sea kayaking between un-inhabitant islands - where there is no possibility to get near to the grid. Even considering a couple of hours of drip charge can keep the GPS, radios and the phone (to get the weather forecast) alive. And if the weather really turns in, then one can realistically foreseen a 17 hours continuous campfire under the tarp ... Also a possible option in case of natural or man-made disaster (read zombie apocalypse ) when devices like Biolite2 remains the only real option to get juice to your critical electronic devices - not necessary a fancy iPhoneX but a humble flashlight. I will try to convince myself to get one of this Biolite2 or maybe wait for the v3 with even more powerfull TEG.
@Rickybob Since the biolite is supposed to minimise smoke you’d be better to stick with plan A and then a firebox nano or similar to repel the midges. Regards John
I'm envisioning something specifically made for charging, not necessarily for cooking. Multiple TEG units ganged up along a firebox, tall chimney for forced natural draft without using power on a fan, etc. Likely not a backpacking apparatus. I also have too many projects as it is.
I had an idea that coupling up the Biolite with a Pyrex kettle/perc would create some pyrotechnics, only really effective when night fell though. The set-up. A fun combination sure enough.
@Marc Check out proper TEG module pricing. Stacking 40 x 40 units I agree is the method, but it's not cheap. Lovely perc shots John.
@presscall Brilliant! Enjoy your campfire and your tea at the same time! Perc your coffee in it, and when you can't see fire anymore, it's done. @Simes Oh yes, for sure, I used to sell electronic components to a company who built commercial TEGs. You'd be able to buy a Honda inverter generator and a looooooooooot of gas and oil changes long before you matched the cost of such a project.
