Have you parked your car for a couple of days in a row without running it, only to be faced with a drained battery the day you turn it on?
You’re left scratching your head as to what could have caused this to happen?
There are a couple of reasons, and none of them have to do with your shiny new LED headlights that you’ve just installed.
LED headlights by themselves are not going to drain your battery when the car is off. Similarly, a separate or a built in resistor is also not responsible. A faulty wire when lights were installed could be the culprit.
Can Aftermarket LED Headlights Drain Battery?
Car owners love upgrading their headlights with LED ones if the opportunity presents. LED headlights to use very little power, are much crisper and brighter in color, illuminate further onto the road, have a much longer lifespan, and most importantly, look very aesthetically pleasing.
But are you worried that after installing your new LED lights, the car battery might drain quickly if the car is left unused and turned off for a couple of days in a row?
Well, you have nothing to worry about. LED headlights barely use much power while running. In fact, most draw an average of 20 Watts per headlight bulb.
With this power draw, even IF you leave your LED headlights on the whole night, they will not drain your battery as halogen headlights would have.
So certainly, when the car is off, absolutely no power should be used up.
Just like stock LED lights don’t drain your car battery, neither do aftermarket LEDs for projector headlights. After all, they are the same component. Being installed later on is no reason for the battery to be affected.
The only reason that you find your car engine not turning on after you’ve left it off overnight, and the only new changes were LEDs. The culprit might be the installation process. More specifically, if the headlight assembly wiring has been affected.
How can you know if it was your wiring at fault? I have you covered, so let’s find out.
What may have happened is that wiring may have crossed over from the polarities at some connection point.
To test if the wiring is correctly installed, remove the fuse from the circuit of your headlights. Then turn on the headlights. They should not turn on since you have removed the fuse.
But if they turn on, the LEDs are getting power from another wire and circuit in the car. And that is where the problem might lie.
After that, you need to do a trial and error method of finding out which circuit is drawing the power.
Trying pulling the fuses from various possible wires going to the headlights. When the LEDs no longer turn on, you have found your circuit. This circuit then needs to be investigated further.
Let’s read ahead to see if additional components installed along with the LED might be causing the car battery to drain quickly.
Will LED Headlights Drain Battery When Used With Resistor?
Since LEDs draw so little power from the battery, the car’s inbuilt computer system often assumes that nothing is plugged in, and due to voltage differences, the LED starts to flicker.
A common fix for this is installing an additional resistor with your LED. The resistor draws extra power, and the computer goes back to thinking all is well.
The resistor removes errors from the computer system, and LEDs run as normal.
Even if you didn’t separately install a resistor, high quality LED kits to come with an internal resistor that serves the same purpose.
Now you may think that since the whole point of a resistor is to increase the power draw of the battery, it might lead to excessive battery drain.
But again, a resistor only draws as much power as is needed to run the headlights properly. Only a small percentage goes to the LED bulb. The majority of power is drawn by the resistor to make up the difference.
This does not lead to excess battery usage. That is not how the resistor functions.
Especially since the car engine is off, the resistor will not draw any power unless there is a mixed wiring polarity, as I said before.
Although the bigger bottom line is that it is essential to invest in decent quality headlights to prevent battery issues. In fact, any other problems will also not crop up if you have made sure to use a well-made product.
One such range of LED solutions is Lasfit. Their LED kits come with preinstalled resistors, and are very easy to upgrade yourself. You do not need to worry about battery drainage issues due to cross wiring as you will not be touching the wires for the installation.
What Is Draining Your Car Battery?
Now that you know what will not drain your battery check out the reasons that do drain it.
As you have guessed already, leaving any kind of lights in the car overnight is enough to drain the battery. It can be your headlights, interior lighting, or even leaving the trunk open that leaves its light running.
Parasitic drain is another major cause, but it happens over a longer time. When small components are wrongly installed, or circuits have faulty fuses, then the battery leaks slowly and goes bad much quicker than it should.
Extremely cold (under 10 F) and extremely hot (over 100 F) temperatures also cause the battery to wear out and not allow it to sufficiently recharge as the car runs.
Also, did you know you need to change your car battery every 3-4 years?
An old battery will result in an unpleasant surprise one morning when the car doesn’t start.
So there are a few ways you can keep your car battery in good shape. As mentioned, most important is getting your hands on good quality LED lights.
Have you been stranded with a drained battery one morning?
Are you considering upgrading to LED headlights?
Share your thoughts with me in the comments below.