Im attempting to install a 10w 850nm ir light to a van. might increase the wattage to 100 in the future. Any knowledge about this and ideas on how to approach this would be appreciated!
1 Like
100W at 12 is 8.3 Amps. for 10C rise in free air, you should use at least 14 AWG wire, but you are not going to be in free air - it’s going to be tucked behind panels. I’d go with at least 12 AWG, and preferably 10 AWG.
How many lights and how much wire? I may have something that will work.
2 Likes
Why? Inquiring minds want to know … 
1 Like
in theory it’ll help illuminate the area for the security camera that’s already installed.
2 Likes
Luckily I have plenty of 10 and 8 gauge ofc wire.
1 Like
1 Like
With a bare LED like that, you will need to provide heat sinking, current regulation or current limiting, as well as an enclosure. A current limiting resistor is the most simple solution, but you are wasting 2/3 of the power before you even make it to the LED. Driver modules can provide much better efficiency.
I have a 6 W IR illuminator that covers the length of my driveway easily. As noted, it does have a brighter central beam, but it lights up the night vision far better than when the pair of 60W (equivalent) white LED lamps come on and the camera goes back to color.
https://www.amazon.com/gp/product/B01G6K407Q/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
2 Likes
Hmmm…wonder if this would mess with all those tag readers out there… 
3 Likes
That would be an interesting project. Car version of infrared counter measures. I would prefer to deploy the flares but YMMV.
1 Like
That might be just what i need. But how would I find out the resistor I need since I already have the ir led?
There are lots of web calculators. Here is one:
1 Like
Mission accomplished 
Thank you everyone for the help!
This is a high enough current device that you probably want to use an LED power supply rather than a 15W dropping resistor. 2.5 amps of continuous draw is going to run your battery down pretty fast. Even with a power supply the draw will be on the order of an amp - not battery friendly.
I intend to add solar panels and batteries in the future but for now… I came across a rechargeable flashlight that met the 10w 850m requirements. Just going to add a relay and toggle switch.
1 Like
The thumb rule is that you need three times the expected demand in solar capacity. and 3 days worth of battery. 2 A for 24 hours is 48 AH, and three times that is 144 AH. 2A at 12V is 24W, and 3X is 72W, so you’ll want ~75W of panels, BUT unless they are steered at the sun directly you’ll need to derate them for the average solar incidence angle. You could pretty easily need more than twice this for panels flat on the van roof.
1 Like
Woah… 
and arnt solar panels 25% efficient? What kind of battery set up would make sense to power 3000w (Portable air conditioner and electronics)
the power stations are too expensive and feel like making one is definitively a better rout.
Check out
1 Like
Holy crap I never heard of this website! Thank you! Why do some systems are 48v? And whats the difference between 12v, 16v-18v, 24-48v… and is it possible to have 2 different setups (12v & 48v) in the same vehicle?
The phone company is a big user of 48V ans so is most of telecom. It’s ususally -48V for historical reasons involving electric trolley cars and lead sheathed cables. .
The typical need is for some amount of power (Watts) to do a job. Power = Volts X Current (Amps.) You size your wiring mostly by current rating, so 4 X Volts = 1/4 Amps for the same power and a whole lot less copper for the same power. Voltage rating of wire is mostly determined by the insulation, so you need to make sure it has enough voltage rating, too. This is usually not a challenge, but some cheap hobbyist wire is rated at 25 or 30 volts.
12 V is the nominal rating of most non-electric automotive systems. It can actually vary from as low as 10 Volts to almost 15 in normal operation. Some transient conditions can see this be 18 or more. A 16v-18v rating is typically an indication that “we’re really conservative in rating this 12 device” though some are for charging specific batteries. 24, 28, 36 and 48V are different nominal values. Most of these are based on the stacking of 2.1 volt lead acid cells into batteries. 24v is also used in trucks and other applications. 6V was common in cars in the early days.
Sure, though typically one connects to the other in some way to allow power to flow and charge batteries if present. There are off the shelf DC-DC converters for this purpose. And of course there is separate wiring, at least for the side that is not common. Note that when used that common connection needs to be rated for the total combined current of both systems.
1 Like