Sometimes you want to light an area or object and there is just no socket-outlet available. This might be the case for photography, work, festivals, camping or any kind of outdoor activities. Flashlights are useful and offer great portability, sometimes however they are just not bright enough or do not offer a homogenous wide-angle light distribution due to their Spot and Spill beam characteristics.

If you need a work light or just a portable light that has enough juice to illuminate a whole area at once have look at the following instructable ;-)

Step 1: Parts and Prerequisites

Prerequisites

- Heatshrink tubing / Lighter

- Wires

- Hotglue-gun

- Multimeter

- Glue

- Cable straps

- Screw / screw nut / washer

- Felt pads

- Duct tape

Specific Parts

- 10W 12V LED floodlight; original ~ 8,15 € / $ 11,3

- DC-DC Adjustable Step-up module; original ~ 1,75 € / $ 2,43

- 18650 Battery Holder for 2 Batteries ~ 1,12 € / $ 1,55

- 2x 18650 protected rechargeable Battery ~ 7 € / $ 9,60

- Switch

Attention! This instructable makes use of 18650 li-ion batteries which can be potentially dangerous due to ignition. Always make sure to store them in a safe location (e.g. a fireproof case or bag) and charge them in a suitable way by using a specialized li-ion charger. I also recommend to use protected cells only since this is a very useful safety feature with little extra cost.

Step 2: Assembly - Battery Holder Mount

Use the pre-drilled holes from the battery holder or drill some yourself with a diameter corresponding to your screws.

Position the floodlight over the battery holder and carefully tighten the nuts with a wrench. Also don’t forget to put the washers in-between.

If a longer battery runtime is desired it is also possible to use a battery holder with 3 or 4 slots (input voltage range of step-up module is 3V - 32V) or to use several battery holders in parallel.

Step 3: Assembly - Switch and Step-up Module

Solder the switch onto the positive lead of the battery holder (wouldn’t really matter which one) and another cable which then connects switch and step-up module. Before soldering put heatshrink on the wires in order to properly insulate them.

Connect the cables from battery holder and floodlight with the step-up PCB and insulate them with heatshrink as well (I widened the heatshrink with pliers so that it initially fits over the PCB).

Use a screwdriver to adjust the voltage output at a small screw which can be found on the step-up module (see picture). I adjusted it to about 13V so that in any case there is enough voltage to power the LED.

Attach the module and switch to the battery holder by using hotglue or superglue (be careful not to block the switch).

Afterwards attach the sturdy cable of the floodlight to one side of the metal frame by fixing it with a cable strap in order to reduce the mechanical stress on the step-up module (in a first attempt the glue loosened because of that).

Step 4: Assembly - Battery Holder Mod

Cut four feltpads so that they fit into the battery holder and a put small strip of duct tape on the head of the screws. This helps to reduce strain of the screw head that would otherwise damage the batteries eventually.

Step 5: Improvements / Review

Done!

Have fun with your portable floodlight!

I chose a warm colour temperature for the floodlight LED. Of course you can also choose a colder temperature if you like, the price for the floodlight is approximately the same.
Battery lifetime could be better. For me it is about 40 minutes. However, I only used cheap 18650 batteries, so the runtime could be longer for a higher capacity.
There is no real protection for deep discharge of the batteries by the step-up module. Therefore you need to rely on the protective PCB of the batteries.
Batteries do not get warm, however the case of the floodlight and the PCB slightly warms-up (about body temperature).