This head-mounted torch may look the part with its huge LED array, but it's just theatre. It does bang out a lot of light, but the unit has two major flaws that limit its functionality.

It lacks a dedicated charge control chip. Instead it uses a single transistor and resistor, with charge limiting theoretically implemented in the microcontroller. (not tested yet) This approach normally results in very slow charging.

It also lacks decent software. It has very basic functionality and would have benefited greatly with some basic PWM intensity control to maximise run time when the full intensity wasn't needed.
It is not suited for use in any application when you need a long run time.

There are four modes.
Single central LED run at 1.98A forward voltage 3.4V (about 7W on a freshly charged cell)
Outer ten LEDs run at a total of 2A
All the LEDs at a total of 2.45A
All LEDs flashing at an average of 1.2A

The software requires you to step through all the other modes to turn it off.
There are no current limiting resistors for the LEDs. Just the cell impedance and the combined resistance of the wires, tracks and MOSFETs.

The lithium cell has the thin wires soldered directly onto its ends (not good practice) and is held into its mounting location by the hot LED heatsink. The capacity printed on it is 800mAh and the first full discharge test logged 731mAh.

The charging circuitry stopped charging at 4.233V which is acceptable. It suggests the chip may have some kind of fixed 4.88V voltage reference. (cell voltage plus the transistor's base to emitter voltage).
The circuitry seems to be similar to a simple lithium charger design that uses a resistor, 4.7V zener diode and a transistor. I'd guess that pin also has voltage monitoring ability as it does stop flashing the charge LED quickly if the cell is just topped up.

I don't recommend buying this light other than for show, as it lacks good design.
If you do want to buy one then here's a link to the item on AliExpress (not a sponsor).
This is an affiliate link, but that will not affect the price you pay.
https://s.click.aliexpress.com/e/_c3quf9kl
At the time of creating this link the price is £2.55

It's kinda frustrating that this could have been a much better and fairly usable product if it had better software alone.



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