Do Rock Lights Drain Your Battery?
It's a fair question to ask before you buy. You are about to wire a set of lights to your truck, and you don't want to walk out one morning to a dead battery. The short answer is no, rock lights will not drain a healthy battery under normal use. They are LEDs, and LEDs sip power. The only way to run a battery down is to leave the lights on with the engine off for a long stretch, and that part is fully in your control.
LEDs draw very little
Old halogen and incandescent accessories pulled real current, enough that leaving a few on could tax a battery in a hurry. LED rock lights are a different animal. They put out plenty of light while drawing a small fraction of what those old bulbs did. Run a set while you are parked at camp for the evening and a healthy battery will not notice. Turn them on for photos, leave them on through a wash, run them on the trail, none of that is the kind of load that strands you.
The one way they can drain a battery
Here is the honest part. Any accessory wired straight to the battery draws from it whenever it is on, engine running or not. Leave any light on long enough with the engine off and it will eventually pull the battery down. That is true of a dome light, and it is true of rock lights. The difference is that "long enough" for a small LED load is a long time, not a quick stop. Normal use, lights on while you are parked a while, engine off, then you drive off, is not a problem for a battery in good shape.
So the real question is not whether the lights drain the battery. It is how they are wired and what turns them off.
How our harness handles power
Our Wiring Harness and Wireless Remote fuses to the battery, so the lights always have power available. The wireless remote, or a switch if you wired one, is what turns them off. That means shutting them off is on you. It is not a downside, it is just how a battery-fed circuit works, and the remote makes it easy: hit off and the draw stops. If you want more on the install itself, we walk through it in rock light wiring 101.
The harness is universal and powers any of our lights. It carries a relay, switch, and fuse, and the remote gives you six strobe modes plus on and off. Connect the battery terminals last when you install it.
Want them to shut off with the key?
If you would rather not think about it at all, wire the lights to an upfitter switch or another ignition-switched source instead of straight to the battery. An upfitter is only live with the key on, so the lights physically cannot stay powered after you shut the truck off. They go dark with the engine, every time, no remote required. You give up the always-available power of the harness, but you gain a circuit that cannot drain the battery because it is dead when the key is out. Either way, keep the fuse in the circuit.
That gives you three clean ways to power a set:
- A switched and fused circuit you run yourself.
- An upfitter switch, if your truck has them, live only with the key on.
- Our harness, wired to the battery, with the remote as your on and off.
Which of our lights are actually plug and play, and what each one needs for power, is its own topic; we cover it in what plug and play means for truck lighting.
Same answer for wheel lights
Wheel lights run off the same harness, so everything above applies to them too. Wired to the battery, the remote turns them off. Wired to an upfitter, they die with the key. Small LED load either way. If you run both rock lights and wheel lights on one truck, the 30 amp harness covers them on a single vehicle, and you still only have one thing to remember: turn them off when you park for the night, or wire them key-on so you never have to.
If your lights ever quit or act up, that is a wiring or connection issue, not a battery one. If a light has truly failed, what actually kills a rock light walks through the real causes, and either way we have a checklist for the wiring side in what to check when a light is not working. Ships from Texas.