another head lamp review

Hello, I'm djozz and I am still not that much into head lamps. I reviewed a Singfire last year, that I won in a DX-thread, and I was not exactly mild about it, I actually wrote that it was a very bad head lamp. Others in the thread kept saying that it was better than I was telling, and I did not agree.

Apparently any news is good news, so recently I got a nice PM from Banggood, asking to review....... a head lamp. Quote: 'Hi djozz, I’m from banggood and I read many reviews from you,they are all nice review' (I do not normally quote from PM's, thought this one was ok, won't happen again)

Ok then, I was actually curious about this one, so here's the review:

The lamp that I received for the review had no brand name, it is this one from the Banggood site. It is actually sold as a headlamp/bicycle lamp, the price is currently 50 dollars . It's design of course originates from the Fenix TK45, and it looks like a chopped version of this Tangspower reviewed by JohnnyMac last year, but the driver is way different and so is the output, more about that later.

It came packed alright enough, like this, and this was inside:

the lamp, a head band, a 4x18650 battery pack with pouch, a plug-in charger with european adapter, some straps for fixing it to a bike.

The UI is simple, it has an electronic switch, one click: first led =on, second click: led 2+3=on, third click: all three leds are on, fourth click: 3led strobe, fifth click=off

Real life: performance.

I first tried it as a head lamp, and found that is very big and front-heavy, 200 grams sticking out far on your forehead is way too much. It is very uncomfortable to wear, and there's not even the weight of the battery pack (I guess the batteries are supposed to be in your pocket, or strapped to your belt). Conclusion: this light is not suitable as a head lamp. Here it is on my son's head, I must admit that at least he was very enthousiastic about it :-) :

As a bicycle light then? It worked much better like that, the beam was nice throwy with enough spill for seeing around as well, on high, the battery pack should last for a few hours (see later). The way it is supposed to be mounted is utterly useless though: being so front-heavy, the rubber/silicone straps were no match for the weight, at the first bump it almost immediately flipped down. Also the battery pack has straps with velcro on a weird place so that is very difficult to wrap it around any possible bar on my bike. It is nothing that can't be fixed with some DIY, but for a 50 dollar light it would so nice if it was done right in the first place. Conclusion: the amount of light (900 lumens, see later), the beam and the runtime are nice for bicycle use, but the insufficient mounting spoils it big time, and I can not think yet of a ready and simple solution for that without creating a new mounting device.

Here's a sloppy video of how I tested the lamp in the park, I compare it to my regular bike light: a 3xNichia219B TIR triple in a ConvoyS5 host.

Virtual life: performance and tear down

So this is the numbers and gutting section. Exclusively interesting for flashaholics I guess.

Measured output: low:292 lumens, mid:586 lumens, high:900 lumens , as expected from a 1,2 and 3 leds user interface.

Throw at high: 10 klux at 1meter.

Some pictures:

The green o-ring around the pill does not stick out, it will do a poor job of waterproofing the led part (not tested in real life above).

Yes, that is paper masking tape

That driver is very different and smaller than the Tangspower driver in Johnnymac's review. It has two sets of led wires coming out, one set for one of the leds, one set for the other two together (they split further down the road).

No brand name or any markings at all on the batteries, but it has some kind of circuitry (for charging? for protection? I am no expert in these things)

The shrink wrap broken in the teardown, I taped the battery pack back tight with duct tape, it is actually waterproof now.

The charger has a red led when charging, becomes green when finished. So there's actually some feedback going on in this charger, sensing the charge state of the batteries. No idea about how safe it all is, it works.

I did some quite extensive electrical measurements on this light for my doing, just because I felt like it, I have never done such a thing in a review before.

Here's some pictures of that with the light on various modes: first picture: voltage coming from battery (2S,2P by the way, the driver is a buck driver with two separate outputs, for led1 and led2/3):

current coming from battery:

current through the led (two leds parallel in this picture):

and voltage over the led:

there's even a voltage over the led if another one is switched on :

the current and voltage numbers :

measured at the battery side of the driver:

*no load: 8V, 0.02A (the batteries were not completely charged here, the small current is probably not reliably measured on the 10A setting of the DMM)

*1 led on: 7.88V, 0.46A

*2 leds on: 7.73V, 0.92A

*all 3 on: 7.61V, 1.38A

measured at one of the leds: 2.96V, 0,95A

measured the current through the two other leds together: 1.9A

So when the lamp is on high, the wattage entering the driver is 10.50W, the wattage used by the leds is 8.44W, giving this driver an efficiency of 80.4%. The efficiency of the light as a whole is 86 lumen/Watt, making this one of my most efficient flashlights (=to be expected from a 'underdriven' light with a buck driver).

Conclusion.

In real life I find this light is not performing according to its retail price, but, as usual with chinese lights, if a little more thought had gone into it (in this case the mounting of the light and the waterproofing of the battery pack), it would have been a useful bicycle lamp. I personally would not have considered for a moment to sell it as a headlamp.

From a flasholic's point of view this light is interesting because of the separate switching of the leds, it will be great to mod it with three very different leds and trying to get the driver to deliver more amps, preferably three amps per led (anyone has a 'sensing resistor' suggestion?).

Hope you enjoyed the review, it was fun to do.

Thanks for sharing , djozz .

Very thorough and nice review

The batteries on all those packs are usually junk, it’s just a nice extra but I certainly wouldn’t trust it.

I figured it was quite a bit too big for a headlamp, that always kept me from getting one of these triple+ headlamps. Bummer.

Thanks.

Thanks for the great review. The light reminds me of the Fenix TK45. Are the reflectors smaller than a P60? Good luck with your resistor mod (and subsequent heat sinking issues) :wink: .

Your helper seems to be starting his addiction quite early in life. :bigsmile:

My helper has his own 20 lumen flashlight, but he keeps stealing my 300 lumen EDC

Oh those are small. 20-21mm? You might do better with optics.