Print Page | Close Window

police lightbar power supply

Printed From:
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
Printed Date: November 30, 2021 at 10:15 PM

Topic: police lightbar power supply

Posted By: stpropguy76
Subject: police lightbar power supply
Date Posted: August 16, 2010 at 3:01 AM


I need Help.

I own a Code 3 MX7000 Police Lightbar, I want to wire it for Inside house use, I need a Cheap Power Supply Idea.

This MX7000 will need to use 40 Amps, I was thinking of using a Battery Jumpbox?

All other Methods are to Expensive. -Buying Power Converters, Marine Battery & Charger, 40 Amp Power Supplys.

I am looking to spend under $100.00 to Power this Lightbar.

Any other Suggestions?

Thank You........................



Posted By: oldspark
Date Posted: August 16, 2010 at 11:50 AM
How long do you want it to run for?

A jumper box might provide 10 minutes (15AH).

Posted By: stpropguy76
Date Posted: August 16, 2010 at 1:28 PM

Hello OldSpark,

Very nice to meet you.

I would like to run this Lightbar every now and then, Maybe 30 minutes a day.

I need a Power Supply with a Minium of 40 Amps to run all of the Lights at once.

I have a Video of this MX7000 Lightbar on you  Search for:   startrekfan76   You will se the Video's of the Lightbar and MX300 Switchbox.

Please do you have any Cost Saving ideas for Powering this inside?

Thank You...............Jeremiah


Posted By: oldspark
Date Posted: August 16, 2010 at 7:04 PM
You'd need a 50AH battery or larger - that's a typical car battery (not small car).
And the charger to charge it over 24 hours.

The bigger the battery, the longer its lifetime.
(Maybe an under-voltage detector is worthwhile.)
If deep cycle, it shouldn't be discharged more than 50%. If a "normal cranking" car battery, discharge no more than 20-30%.

If the battery is indoors, it must be an AGM type(or other approved "sealed" types).

To save power, decide what features you do not want to run for what period of time.

Posted By: stpropguy76
Date Posted: August 16, 2010 at 7:34 PM

Hey OldSpark,

Thanks again for your Suggestions.

But looking at them brings me back to Cost, I have been told that I would need a Deep Cycle (Marine) Battery instead of the Regular Car Battery, The Cheap ones start at $80.00 + Core charge.

Then there is the Charger that Startes at $35-$40.00

So looking at it I am still spending around $120.00 For a Cheap Battery & Charger  

That defeats the reason for the Posting, I am looking for an Indoor Power Supply UNDER $80.00

What if I skip the Battery Totally and just use the Charger?       Or maybe a 300Amp Jumpbox?

Hook it up to the Charger or Jumpbox to the Switchbox/Lightbar wires, Then plug the Charger or Jumpbox into the wall, And power on?

What about that?, The Charger or Jumpbox should change Ac into Dc for the Lights. 

That way I'm still under the $80.00

But I have a guy that has a Cascade Audio 75Amp Power Supply that Plugs into the wall and also Converts Ac into Dc Power, He wants around $125.00 Each, If I go this route I'm only $5.00 more than for the Battery & Charger.

Still looking for Ideas?


Posted By: stpropguy76
Date Posted: August 16, 2010 at 7:36 PM
Sorry, I don't know why I said $80.00?


Posted By: oldspark
Date Posted: August 16, 2010 at 7:52 PM
What size is the battery in the jumpbox and its charger?

If its charger handles 40A, you'll be fine (but it won't).

If the battery lasts 30minute and it recharges within 24 hours, it'll be fine until the battery dies (that depends on battery type and how far it is discharged).

Or get a 12V/13.8V 40A supply, else 24V/27.6V(20A?) if you have the 24V lightbar - you won't need a batery.

Posted By: stpropguy76
Date Posted: August 16, 2010 at 8:02 PM

No,  I have the 12V Lightbar (Code 3 MX7000).

You can see this Lightbar and Switchbox, I made a you Video, Go to you, Search  startrekfan76, You will see the Video's.

So would I still need the Battery or could I just use the Car Battery Charger?


Posted By: stpropguy76
Date Posted: August 16, 2010 at 8:05 PM

There I go again, It is you

Search Video's by   startrekfan76


Posted By: oldspark
Date Posted: August 16, 2010 at 8:55 PM
If a PSU can power its load, then no battery is needed.
Be aware that battery chargers may not be good PSUs - they may be poorly regulated, and they can be noisy & require a battery for filtering etc.

If its only for testing (or sale), why not use a car and its battery etc?

I can only suggest searching eBay & google etc for a suitably cheap supply. 40A DC supplies are not cheap.

Posted By: 91stt
Date Posted: August 17, 2010 at 11:08 AM
You can build a regulated power supply from an old ATX psu. a 600+ watt psu with a single 12v rail should give you the 40 amps you need. Here are some sites with instructions to give you an idea what it would take to build:

If you don't have an old psu that provided enough current, you can always find them online to fit your budget.
The components can be purchased from online sources like
I have built 1 out of a 200W supply that works well for testing various electronics.
Since you only need a 12V, I would just build it to supply 12V only and insulate all of the other wires and not bother terminating them.

This information is provided only as a reference.
All circuits should be verified with a digital multi-meter prior to making any connections.

Posted By: js305
Date Posted: September 05, 2010 at 4:32 PM
Be aware that a "40 amp power supply" usually is only rated for 2/3 of the rated 40 amps for continuous use. So, if you need 40 amps for 30 minutes you better be looking for a 60 amp supply. More money...

I think your cheapest way out is to get a car battery and a charger. Go to a sure nuff battery supplier (not and auto parts store or a big box store) and ask for a reconditioned battery. Chargers can be bought pretty cheap. Get a low output one and use it only for charging, not at the same time as the lightbar is being used.

Joe in Texas

Print Page | Close Window