DIY battery power distribution mount

[hogshooter]

Ever since I decided on a winch, I've been looking for a solution that would give me several points of direct access to the battery, since I already have a compressor mounted in the rear.

I knew with the winch bumper I was getting, I'd also need somewhere for a relay for the 20 inch light bar to live.

about a month ago I started buying parts, and looking for spaces under the hood to mount a large(ish) power distribution station. I first started with a panel that mounts on top of the fuse box next to the battery, but with the few prototypes I made, I barely had enough room.

I then moved on to a plate that attaches to the battery hold down strap, which is what you see below. I have to drill a second hole in the strap, so there would a nice locked down plate. I used flat head screws so the attachment to the strap wouldn't cost me any layout space, and after a few prototypes cut in 1/4 acrylic, I landed on this design last week.

It has:

4 post negative bus bar with 4 8mm posts and a ton of 4mm screws
4 post positive bus bar with 4 8mm posts and a ton of 4mm screws (one of those is feeding the Blue Sea block)
6 position Blue Sea distro block for lower amp power needs
4 position relay bracket

bus bars are connected by 2 gauge wire.

Acrylic is the easiest material for me to prototype, I can cut it on the laser cutter in my shop. I"ll probably have one made in powder coated steel by SCS, but I might stay with acrylic since it's not conductive. It's still a work in progress but I feel like I'm 90% there with this one.

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[MHG]

You did a great job. I have spent the last 25 years upfitting police vehicles and mobile command posts and I cringe when I see these $600-$900 options some of these companies bring to market.

However having done a post fire inspection on a $100k surveillance vehicle I would strongly suggest fusing that buss bar. I had a contractor fail to fuse an inverter cable and when doing the forensic examination on the burned out vehicle it was clear that a simple fuse no more that 12” on any battery connection would have saved that vehicle.

 

[hogshooter]

You did a great job. I have spent the last 25 years upfitting police vehicles and mobile command posts and I cringe when I see these $600-$900 options some of these companies bring to market.

However having done a post fire inspection on a $100k surveillance vehicle I would strongly suggest fusing that buss bar. I had a contractor fail to fuse an inverter cable and when doing the forensic examination on the burned out vehicle it was clear that a simple fuse no more that 12” on any battery connection would have saved that vehicle.

Thanks, what amp fuse would you recommend?

 

[Bravada]

You did a great job. I have spent the last 25 years upfitting police vehicles and mobile command posts and I cringe when I see these $600-$900 options some of these companies bring to market.

However having done a post fire inspection on a $100k surveillance vehicle I would strongly suggest fusing that buss bar. I had a contractor fail to fuse an inverter cable and when doing the forensic examination on the burned out vehicle it was clear that a simple fuse no more that 12” on any battery connection would have saved that vehicle.

I've got a similar setup planned. Can you please recommend a fuse?

 

[MHG]

Well I would probably total up the amperage of all my gear connected to that buss running at once. Not necessarily the total of each fuse. For example the Cali Raised light bar harness has a 30 amp fuse. Their light bar is no where near 30 amps. But not everyone has a DC Clamp meter. (Klein makes a great one for less than $100. Just make sure it’s clamp measures DC amps)

In most cases 80-100 amps is plenty. But big fuses cost big bucks if your wrong so do the math. The maximum current of that cable from the battery to that fuse/breaker should not be exceeded.

A best practice is anything connected to the battery should be fused no more than 12” from the terminal. I like the circuit breakers. You can use them to disconnect all your gear for troubleshooting and storage. The circuitry of all that gear has a parasitic effect on the battery. Also the dealers like to blame your gear for draining the battery so a simple disconnect is a best practice as well.

 

[hogshooter]

ok, so my winch is rated to pull 360A at max load, and my compressor is rated at 68.6A at max load. My light bar is 15A. So I would need at least a 450a breaker or fuse, correct?

 

[MHG]

Probably since it is theoretically possible for all of your components to be operational at the same time. Winches bring a whole new dynamic as you can have short term current surges that exceed the winches rating.

However that jumper from the battery to the bus will likely go up in smoke at that guage. Something at 4guage or even a 0 guage would be better at less than 1foot between the battery and a circuit breaker or disconnect.

I typically run circuit breakers on everything except the winches. Those I put a disconnect on. But you can get big breakers.


There are some guage calculators online that will give you more details.

 

[hogshooter]

I did some reading, seems like the disconnect switch is the way to go with the winch. Thanks for your input.

 

[MHG]

Yea. You don’t want to get into a car accident and have that winch cable get shorted.

 

[Type2Diabetes]

Well I would probably total up the amperage of all my gear connected to that buss running at once. Not necessarily the total of each fuse. For example the Cali Raised light bar harness has a 30 amp fuse. Their light bar is no where near 30 amps. But not everyone has a DC Clamp meter. (Klein makes a great one for less than $100. Just make sure it’s clamp measures DC amps)

In most cases 80-100 amps is plenty. But big fuses cost big bucks if your wrong so do the math. The maximum current of that cable from the battery to that fuse/breaker should not be exceeded.

A best practice is anything connected to the battery should be fused no more than 12” from the terminal. I like the circuit breakers. You can use them to disconnect all your gear for troubleshooting and storage. The circuitry of all that gear has a parasitic effect on the battery. Also the dealers like to blame your gear for draining the battery so a simple disconnect is a best practice as well.

I would stay away from the red wolf brand circuit breaker, I’ve had one that would not manually delatch “break” on an aux battery setup I had on my superduty.

Maybe just a one off but caused lots of anxiety on a lengthy off grid camping trip, although I had another circuit breaker for the circuit in the bed as backup.

Blue sea systems makes these as well, I hear they have a pretty good reputation but more $$.

 

[MHG]

I would stay away from the red wolf brand circuit breaker, I’ve had one that would not manually delatch “break” on an aux battery setup I had on my superduty.

Maybe just a one off but caused lots of anxiety on a lengthy off grid camping trip, although I had another circuit breaker for the circuit in the bed as backup.

Blue sea systems makes these as well, I hear they have a pretty good reputation but more $$.

Sorry, gave the photo to show the type, but not necessarily the specific brand. I prefer all the blue sea stuff myself.

 

[Delta1Seven]

Awesome idea! I just installed a 8-fuse panel for a Auxbeam switch panel, but I mounted it directly to my fuse box cover and I am not in love with it. I like your mount much better.

Is this just standard 1/2" Acrylic? Amazon also shows results for polycarbonate which looks very similar.

And can you just tap the threaded holes just as you would with metal?

 

[hogshooter]

Awesome idea! I just installed a 8-fuse panel for a Auxbeam switch panel, but I mounted it directly to my fuse box cover and I am not in love with it. I like your mount much better.

Is this just standard 1/2" Acrylic? Amazon also shows results for polycarbonate which looks very similar.

And can you just tap the threaded holes just as you would with metal?

I used 1/4 acrylic. It is a different material from polycarbonate. You don't want to laser cut polycarbonate, it off gases chlorine gas, aka mustard gas.

I didn't tap the holes, if I make one out of metal I will tap those. Tapping acrylic is possible, but it's easy to over torque and shatter the threads.

 

[Delta1Seven]

I used 1/4 acrylic. It is a different material from polycarbonate. You don't want to laser cut polycarbonate, it off gases chlorine gas, aka mustard gas.

I didn't tap the holes, if I make one out of metal I will tap those. Tapping acrylic is possible, but it's easy to over torque and shatter the threads.

Good thinking about not tapping the holes. Also, I appreciate the feedback.

I can't think of a another non-metal material that will work better than acrylic.

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