As much as I probably think your right knowing KD, you have absolutely no evidence to base that on.
This light could have markedly better quality than the MTE, and if my MTE lights are anything to go by it probably does.
It's probably best to leave the overpricing talk until someone actually has this light in their hand!
I was thinking about buying the Eastward YJ-XAQ5 flashlight but now I won't. I guess Jerry from KD read the good comment and immediately raised the price. This is not a good practice.
This forums are to share experiences not to take commercial advantage of comments.
I invite everybody to do the same I am doing until KD updates the price to the previous one.
http://www.kaidomain.com/WEBUI/ProductDetail.aspx?TranID=4357
"- Features a Cree 7090 XR-E P4 emitter" lol
look the photo, it is not a cree
I can understand a 1.5V step up circuit, but is it really possible to have a 1.5W step up circuit? Isn't the output in watts determined by the capacity of the 18650 cell?
But why would a 18650 light have a 1.5V step up boost circuit?!I think this part is a simple mistake where it should say 1.5V not W for watts. As you already know power can't be stepped up, Whatever total power you have from the source is all you can deliver minus that lost in the circuitry to get it there. The step up voltage converter most take some power across itself to run, nothing is 100% efficient so if the batteries could deliver lets say 10 watts of power continuous steady state (this is just an example, don't crucify me for the actual numbers) and the power conversion circuit took 0.5 watts of power to run, the most that could ever be delivered to the load (in this case the LED head) would only be 9.5 watts. You could never take a 10 watt source and step up the power to make it an 11.5 watts at the output. Not unless you had those good dilithium crystals from the Federation and not those cheap Klingon Crystals.
So I am sure that they meant 1.5V step up, but once again it proves the point, the guy making up the ad just uses the buzz words without understanding them. So you don't know what he is really advertising versus hype.
But why would a 18650 light have a 1.5V step up boost circuit?!
Yes, I know how things works (battery/regulation freak), but I kind of doubt that this light has a buck/boost circuit, very few of the cheap 18650 lights does (and it bugs me). Anyway, a lithium can't go much lower than 3 volts without taking damage, so a boost circuit that works down to 1,5 volts would be kind of wierd. But if it has a buck/boost circuit, it's a big plus.To give it longer run time range as the battery runs down. It doesn't stay at peak voltage forever, especially under heavy load. The 18650 battery may be better than others but that doesn't mean it doesn't have any voltage fall off curve. The vendor wants to be able to give you the most useful run time for your money so the voltage is stepped up just enough to give the regulation circuit "headroom" to keep it constant across the LED head when the voltage finally does start to sag at the battery. The higher the current load the more the battery voltage will sag, even with the best of the best, its just a matter of how much. If these flashlights are really drawing up to 2.8 amps on high mode that battery isn't going to be holding a rock steady voltage until its ampere hour charge is 95% used up, its going to sag somewhat over time. With just the right amount of voltage step up and a good regulation scheme, you will never notice it at the light output end, and get the most optimum run time besides (without wasting a lot of power across the regulation circuit itself) which is after all what you want right?
Since they know that this thing won't have a really long run time at full power or near full power, they are trying to get you the most out of the battery so you won't complain that it runs for 15 minutes before you start to see the brightness drop.
Not to mention that even though the battery with a fresh charge may have high enough voltage, at the higher current levels there is some resistance in the connections to get that to the LED, that resistance will have some voltage drop to over come as well (I times R = V), so better to have ample Voltage headroom and not need it than to be on the verge where the light just goes dim at full power setting.
The resistance for instance through copper goes up when it gets hot not down. That means it becomes slightly more resistive. A 50 milliohm total shall we say wiring path resistance (this is just an example for the math illustration) or 0.050 ohms times 2.8 amps is a 0.14V drop right there. May not seem like much, but as contacts get old and cruddy things change. Make the electronics give you a voltage range up to possibly 5.5V peak and no less than 4.5V and then its not a concern any more, for most of the life of the unit under "normal" conditions.