Hi Tyler,
18W Led at 12V supply will draw 1.5A Max. Rule of thumb, the size of wire handling current must be double of the rated current means you use a wire can handle at least 3Amps. For a single LED is normally rated at 30mA to 50mA. On the link you supplied, it indicates 36 LEDs for this light means each LED is rated to 18W/36 which is equal to 0.5W. So the rated current in each Led is equal to 0.5W/12 which is equal to 41.6mA which is correct within the 30mA-50mA.
How long you can run the light for a new 12V car battery.?Most car batteries has at least 300Ah means you devide 300Ah by 1.5A whis is equal to 200hrs of continuous usage. What is you use a dimmer control in series to reduce the current by half means the hours will be doubled to 400hrs continuous usage.
With the used battery with reduced charging capacity let's say only 50Ah means you can the light continuous with dimmer control for roughly 67hrs. If you use only 2hrs a day means 67/2 is roughly 30days before you charge the battery.
Make sure you use an inline fuse rated just above the light maximum rated current (let's say 2A fast blow fuse). Use an inline switch between the fuse and dimming control so you can leave the alligator clamps connected to the battery.
You have lots of options for charging, using solar or mains trickle charging.
Cheers,
CM
Last edited by thecarbymaster; 04/08/22 09:57 PM.
