How long will your batteries power my lights?

Batteries : Making your LED lighting portable since 1800

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Using battery to our LED lights really makes everything a lot easier and handy. Battery packs are relatively simple, you charge them and plug them in, and your lights turn on! A little more complicated, however, is figuring out which battery you need, and how long it will power your lights for.

Today, we're going to figure that out. All of our strips draw a certain amount of Watts, or power, from either a power supply, or in this case, a battery. The capacity of batteries is measured in mAh (milliamp hours) or Ah (amp hours). One mAh is one thousandth of one Ah. The batteries we sell have a capacity of either 3500 mAh (3.5 Ah), 6500 mAh (6.5 Ah), or 20000 mAh (20 Ah). But how do they relate to Watts?

Let's break out some math.

That's also relatively simple. The electrical power formula states that Watts = Amps x Volts. Our lights run on 12 Volts. So if we plug that into the formula we realize one amp is the equivalent of 12 watts of power. Thus, our three batteries actually contain 42 Watt Hours (12 x 3.5), 78 Watt Hours (12 x 6.5), and 240 watt hours (12 x 20) respectively. From here, your total battery capacity in time is pretty easy to calculate.

Start with the total Wattage of your strip - let's say the Standard Density Luma 5 strips at 21.31 Watts, and divide that battery capacity by that number. From these we find that the 3800 mAh battery can power this strip for 1.97 hours (42 / 21.31), a 6000 mAh battery can power this strip for 3.66 hours (78 / 21.31), and a 20000 mAh battery can power this strip for 11.26 hours (240 / 21.31).

The Battery Life Calculator I HitLights

Our calculator is a simple and easy-to-use tool that computes the estimated number of hours, days, and weeks that your battery will last if you use it for your 12V lighting needs. All you need to do is input your battery's capacity in mAh and the watts of the lights you'll be using, and our calculator will do the rest.

It's science!

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Those times are good enough for most applications, but if you do the math and you're looking for more run time, then the only answer is more capacity. There are a range of 12V batteries available, but they're mostly large. A car battery, for example, will be in the 60 Ah (720 Watt Hour) range, which is more than most people will ever need. 


Got battery lifespan down? It's just one small factor in LED lighting. Choosing the right LED light strip for your project is also important, and our free eBook, titled 'How to Choose LED Strip Lights' is an ideal guide in the next stage of your LED lighting journey.

If you have any additional questions? We're here to help, contact us at or 1-855-768-4135. Our expert team of electricians and engineers will help you every step of the way!



Great blog, simple and to the point, so glad I found this resource…

Lucius Jones

Nice blog. I read your post. your post is very useful for everyone. thanks for sharing.
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