Just wondering if its as simple as getting a 12v LED strip and connecting the positive and negative or is there more to it?
I’d like to put about 1 to 1.5 meters of warm white LED strips under the parcel shelf so when I open the boot/trunk it lights up.
Also is there anything to look for when choosing LED strips, like brands or some measure of output or type of LEDs used?
Thanks for any advice.
Car voltage has a pretty wide range, from as low as ~12.2 up to 14.4 or higher, depending on battery state of charge, electrical load, voltage regulator cutoff point, engine running or shut off, etc. LEDs need a steady, consistent voltage or else the current will change by a rather large amount too.
I use these to power '10W' COB LEDs in cars. Work great. Adjust the voltage to give the desired current. There are many different designs that all do the same thing more or less, search for 'DC-DC converter'.
I've had about a 2 1/2 - 3 foot strip in mine for about a year now in a car I drive daily. My dome light broke so I just wired it straight to the 2 wires going to the dome light. Seems to be fine. It does get quite warm when I have the door open for a long time. Someday I will mount it to an aluminum strip. I have accidentally left the door ajar for a weekend and part of a weekend. It discolored in spots from the heat but still works fine (sunny weekends parked outside). It is one of those sealed multicolored jobs (R,G,B,W). I have all colors connected.
Typically, my engine is off when the door is open. So input voltage is about 12.x
EDIT: My strip appears to have a SMD resistor for each group of 3 LED's.
That’s standard, since the Vf of three LEDs is considerably less than 12 volts, and happens also to greatly reduce the variation in current with changes in voltage.
I have a 3’ strip tied into the feeble existing light that is on the lower portion of my hatch and is always obstructed by hatch contents. I have had several people stop and ask me about it in parking lots when I’ve been loading groceries etc.
This is a 12v waterproof LED strip from DX I believe. They are designed for car use and don’t seem to mind the voltage variation at all.
Wow thats pretty awesome, not a bad idea at all. My car has a similar hatch/light system. Did you wire it so that the switch in the boot area also controls this strip? Does it just pull power from the wires that go to the original light or did you have to run it all the way to the battery?
Thanks!
I popped out the existing fixture and soldered a female auto light socket to it. I soldered a male socket on the strip wires. The connection lives right behind the stock fixture in the panel. It all functions with the switch on the hatch. Both the existing light, which has an LED bulb in it, and the strip go on and off with the hatch opening and closing. I can also turn it on and off with the little switch on the stock fixture.
It is bright enough to do surgery back ther now.
It warms up, but is not ever hot enough to worry about even after the hatch has been open for a long time.
I had trouble with the supplied adhesive backing on the strip even tough I cleaned the surface with alcohol before attaching. I fixed it by using 3M automotive double stick tape.
If you require more pictures I can take some by tomorrow.
Would a small 12vdc L7812 regulator board help stabilize The voltage?
schizobovine - Postage Stamp Regulator Mk 3 - WarHawk’s Tweak
Top:
It’s my tweak of someone elses board all I did was rotate some caps, move a trace, and make a polygon pour to increase the copper pour on the back side for more surface area for better heatsinking
Comfychair, that driver you posted, what’s the chip? I’d like to read up on it. Can’t make it out from the pictures. Thanks 
hiddistributor on ebay is where I have purchased strip lighting for my truck. Lots of choices and U.S. seller.
I have 3 different versions...
Are you sure? Crawl into the trunk and have somebody seal you in overnight just to be sure… J) Oh, and do the same with your refrigerator and freezer…
Note that you should drive LED strips with the power source”+” connected at one end and “-” at the other… very important for longer strips. If you don’t, you get a significant voltage drop down the strip and the LEDs at the driven end draw more current and those at the open end get starved for power.
Haha, if it wasn’t a hatchback I might have tried that
daggum, didn’t realise they were THAT small, wow!
Thanks guys