Be aware that the Anker USB portable battery boxes sold through Amazon list their capacity at 3.7V so the effective true output capacity at 5V is closer to 70% of the claimed mAh capacity. Checking around this seems to be an industry standard for virtually all of these portable USB power sources. I think it is deceptive advertising as I have yet to see a product listing which notes that the capacity listed is based on mAh at 3.7V battery capacity rather than at 5V output voltage. I want to know useful output capacity at 5V, not the capacity of the batteries in the box.
IMO even worse than ANSI flashlight run time being to 10% of output and throw distance being to a light level which can only show highly reflective objects.
I do not share your opinion. While I would like to see more comprehensive data from the manufacturers and sellers of these packs, I do not think that what you’re seeing here is worse than the ANSI runtime standard, or particularly terrible really. Like a battery, actual available mAh will depend on load. At full load mAh should tank pretty spectacularly. At lower loads it will be much higher. Asking for the current [potentially] misleading single number to be replaced with a different potentially misleading single number is pointless. At least we know where this number comes from (it is directly copied from the cell manufacturer). Even if you specify test conditions a “mAh out” number would be mostly worthless. Without the spec, entirely worthless - it would have less merit than the currently advertised numbers IMO.
wight; I see your point but none of the USB battery power boxes seem to clearly state in their specifications that the capacity listed is at 3.7V. I noted it because SOME units list it on the power unit itself. As for changing capacity with different current draws most such units, except the highest power ones, are limited to outputs between 1 and 2 Amps at 5V and per HKJs 18650 battery reviews most decent batteries have quite close to the same capacity until the current draw becomes quite high.
My major objection is not so much that they specify things the way they do but that they carefully DO NOT MENTION that the capacity is listed for 3.7V as it seems apparent, based on customer reviews, that many are thinking that the capacity being listed is output capacity @ 5V. The capacity specifications listed are incomplete as long as the voltage involved, or the theoretical watt hours capacity, is not listed. One unit I have actually lists voltage and watt hours but only on the device itself, not in the Amazon listing. Not even a statement any where that the capacities listed are battery capacity rather than output capacity.
Give the customers full information on tech devices so the technically educated ones can make informed purchases with full knowledge of what they are getting.
IMO it doesn’t matter very much as long as we’re all playing by the same rulebook (where all manufacturer’s spec @ 3.7v). It allows easy comparison on the only metric these people can be semi-trusted about…
When it comes to output currents, this is where it may get trickier than you realize. The batteries will be fine at 2A, 3A, etc - they don’t sag at all. [Especially since they are in parallel of course!] The boost circuit? Not fine. Trying to get 2A or 3A @ 5v out of a bank of cells which is at less than 4v gets some pretty low efficiency out of those boost circuits I think. I’m assuming that’s where your most significant variations will be between chargers. That said, I’m not the most educated person on this subject so I’m happy to be proven wrong about the efficiency tanking.
That seems like a pretty good deal. At one time it would have been a very good deal. I would rather spend $40 more for a TK-61 though. More battery capacity, larger reflector, more heat sinking, and more moddable for higher voltage emitters like the MT-G2 and whatever comes out in the future.
Thanks for the comments. I posted that deal there. To be honest I am not sure if it is a good deal or not. Mine was from at least two years ago at $120. But nowadays it may not quality as a satisfying thrower any more.
They now have both neutral white and cool white for $79.95, last week the cool white was $10 more. Just received my neutral white today. Now have 2 stock and 1 modded TN31. The modded one will out throw anything I have. My modded one was done by TomE but I think I’m going to try and mod the other cool white and leave the neutral stock. To me I think this is the best deal going especially if you can mod. One more thing, the ones on sale at Amazon are shipping only in a cardboard box, not the aluminum case.
If you missed this deal, Black and Decker makes a great rotary tool for a tiny price. Usually B&D stuff is utter crap, but this is the exception. It outlasted my Dremel brand tool easily. The cost savings is partially from B&D not including a bunch of accessories, but they use the same bits as Dremel so you can just get the ones you need.