Custom battery solution for flexible LED panels

Hello.

I want to create a custom battery solution for some flexible LED panels that I bought for video work.

The panels have the following specs:

2Amps
24V
48W

Those are the “on sheet” specs. I tested the consumption and was actually a little lower with the original PSU.

The requirements for the battery bank I want to make are that each lithium battery needs to be under 100Ah to be able to be taken on a plane, and that I would like to stick to a battery that I can use for something else.

There are V lock and L series batteries that are used commonly for video work but they are costly and their use, other than for the lights, would be limited for me.

I intend to use Milwaukee M12 tool batteries because I already have some and I have Milwaukee tools, so I can utilise the batteries for the tools. They also have internal over discharge protection and the chargers are both quick and condition the cells each time.

I tested a panel with two of these batteries running in series and they are capable to power the panel, but once they start loosing the charge, there is a dimming effect in the intensity of the light. Hence I need a device to regulate the power.

These batteries fully charged hold 12.04V (24.08V in series) and after an hour of running the light they are about 11V (22V in series). They are the 2.0Ah version.

So my question is. If I was to run two of these 12V 6Ah batteries in series, or even 4 of each in a 2 in series, 2 parallel configuration. Which DC-DC solution would you suggest to keep the output constant at 24V-26V?

The 150W DC-DC Boost Converter 10-32V to 12-35V 6A SKU: 018-DCDC-BOOST-150W https://core-electronics.com.au/150w-dc-dc-boost-converter-10-32v-to-12-35v-6a.html

Or the Pololu Adjustable 9-30V Step-Up/Step-Down Voltage Regulator S18V20AHV SKU: POLOLU-2573 https://core-electronics.com.au/pololu-adjustable-9-30v-step-up-step-down-voltage-regulator-s18v20ahv.html

I need to build three battery units to run up to three lights at the same time.

I already added those two converters to my wishlist waiting for you advice and clarification.

Kind regards,

My recommendation would be to use the 150W DC-DC Boost Converter 10-32V to 12-35V 6A SKU: 018-DCDC-BOOST-150W https://core-electronics.com.au/150w-dc-dc-boost-converter-10-32v-to-12-35v-6a.html

My reasoning is that it’s dangerous to operate at the 2A max output of the Pololu step-up/step-down. Although I feel that this type of converter would be better and more efficient.

As things stand, the boost converter is likely to get quite hot while in operation. I would use two Milwaukee batteries in series to get 24 volts charged, The boost converter can keep this at 24 as the voltage drops. They should shut off before reaching 10V each. The boost converter is 94% efficient, and the batteries have a 1.5Ah capacity. I would expect to get two hours of run time if you are running bright. The 2A draw from the LEDs would be max draw, with all lights set to white. the realistic draw is usually slightly over a third of max.

I hope that helps, be sure to share your finished project on our forum!

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Thank you very much Stephen! It does make sense.

I was hoping to use the Pololu unit as it seems smarter, but I failed to take into account that it will be at the top of its rated output.

Still I have used the multimeter at 100% intensity at every colour temperature and it comes at 1.8A but I think the PSU may not be strong enough. I am measuring at the 24V end.

Does it make a difference if I use the higher mAh batteries to have a longer running time?

I will share the project for sure.

I am 3d printing the battery holders and attaching them to a plate and from there to the converter to a 2.1mm plug for the lights.

These are the lights I am making the battery bank for:

Now I am excited! The crazy idea I got is getting closer to become a reality.

Oh! I didn’t realize they were white LEDs. They will be drawing at or near their promised load so 1.8 sound about right. Bigger capacity batteries would mean more run time. You could also connect some batteries in parallel. Connecting batteries in parallel adds up the amps, connecting in series adds the voltage. You don’t ever need to worry about providing too many amps, your electronics will only draw as many amps as they need. Voltage is the critical thing to get right.

The Amp hours of the battery is the best representation of how much power it holds. If you are drawing 2A then a 2Ah battery will last one hour.

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You still would not use the Pololu because it is close to their specified 2A. Right?

Thank you Stephen

The Pololu is rated to 2A, but that is likely peak current only. You stand a good chance of over stressing the Pololu. For that reason I do not suggest it for this project.

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Hello @Stephen

I left a technical post in the projects page.

I will be leaving another one once I make the 12V batteries solution.

Cheers.

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