How to power led lights with a battery

A few days ago we received a query from one of our readers, interested in the subject of autonomous lighting for a stall that he plans to set up. Not having an electrical connection to the network, he needs to know how to power led lights with a battery. Our idea is to use a car battery and 12-volt LED lighting. Let’s see what aspects must be taken into account for this type of installation.

Materials need to power led lights with battery

  1. 1.12 v Batteries
  2. 2.12 v LED light
  3. 3.Wire

12V batteries

Car batteries (motorcycle or truck) are designed to offer high intensity for a short period of time (starter motor), therefore it would not be the most suitable for lighting. Anyway, if you already have one, you can use it with the only drawback that it will degrade before a specific battery for these uses.

Approximately the capacity of a battery will be:

Car battery: between 50Ah and 100Ah

Motorcycle battery: about 12Ah

Truck battery: between 175Ah and 225Ah

With this data, we can know approximately the duration of our battery depending on the lighting power that we install.

As it is obvious to recharge it we will need a car battery charger. Be careful with trying to recharge it by connecting it to the car since below a discharge level it will no longer be possible or it would take forever.

12V LED lighting

There are many options for lighting at 12V with direct current, most of them come from the automotive world. In our case we will look for the lowest energy consumption to extend the battery life as much as possible , therefore we recommend installing 12V LED lighting.

A good example would be a 20W 12Vdc LED spotlight. With this focus we would achieve a brightness of 1450 lumen, equivalent to a 120W incandescent bulb.

You can buy a LED spotlight like this one in the online store , they also have 10W, 30W and 50W models in case you need another power.

If we are going to use outdoor lighting it is important that the 12V LED spotlight is prepared for it, in this case there would be no problem since it is IP65 : strong protection against dust and protection against water jet.


As for the battery life with the selected LED spotlight, we can make an approximation as follows:

If we have a 100Ah (saloon) car battery, we will have 1200Wh (100Ah * 12V) accumulated, so our 20W spotlight can shine during:

This is the theoretical duration leaving the battery to zero, which is not possible since, among other things, it would be damaged if it drops below 11.8V. So we must have less autonomy than the theoretical, 50% of this number would be the most appropriate being conservative: 30h.

Wired at 12V

In 12V power systems, we must pay special attention to the cables we use, since it is a low voltage, the intensities are going to be higher than 230V, therefore we need thicker wires. In our example, if the cable run is going to be more than 10 meters, for security it would be convenient to use 2.5mm 2 cables.

Conclusion: Now you know how to power led light with a battery, and try to make it as your need. Before using any electric product be careful and take full safety.

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