Here my version of the powerful led flash, once you have all the parts it can be build in 1-2 hours...
Step 1: Bill of Material
- A 100W led chip (32V 3A)
- Lens, reflective cup and frame for led chip
- DC DC step up 12V to 32V, constant current and constant voltage (I choose 600W, but a 200W should be ok)
- Fan + heatsink, led chip heats a lot
- A 3 position selector switch. On, Off, and Charge to charge the battery
- Lead battery, 12v 9Ah, should work for at least 30min.
- Voltage and current display monitor
- Lead battery charger.
- MDF panels (2 panels 11cm x 10cm and 2 panels 10cm x 33cm)
- Some screw
- Wood glue
You can change properties of few part, like power of the led chip, capacity and voltage of the battery, but you need a DC DC step up with constant current.
Step 2: Build It
Drill a hole in the small MDF panel for the led assembly. Size of hole is big enough to see the led chip but small enough to avoid the chip to through the hole. Screw heatsink against the led chip (add thermal paste). On the other side of the MDF panel, screw the lens assembly. With 1cm thickness the reflective cup shouldn't touch the led chip.
On the big MDF panel, install the selector switch. Wait the end to install the handle. On the other one glue the 2 small MDF panel. Put the battery at rear, secure it with some screw. Install the DC DC step up with 2 long screws through its heatsink.
Connect the battery to the DC DC step up module, through switch selector. Also connect the fan after the switch.
Add the current and voltage monitor to know when the battery is empty (around 11V).
Use voltmeter and ampermeter to set the DC DC step up module (you can disconnect fan for this step) to 32V 3A.
Screw 2 terminals to charge the battery, connect on the third position of the switch.
Install the top panel with 3 metal squares and screws, and screw a cheap handle at the "balance" position of the flashlight
Step 3: Improve !
You can improve the case (paint for exemple), add MCU to control temperature and current, do a better cable routing, etc etc. You can also remove the current setting pot on the DC DC step up and put one on the case to set the power (and autonomy) of the flashlight...