mount busbars on wood ?

[WoodsieLord]

I'm building a 24V lead acid battery bank and I was going to mount both positive and negative bus bars onto the wood structure that will hold the batteries in place.
I saw a thread recently where a user shared a near disaster experience where wood planks were in contact with LiFePO4 cells. My personal and non-professional point of view is that wood should be non conductive for 12V~24V.

Should I under no circumstances screw the bus bars to the wood? You think I'm a mad man?
What would you do in my place?
I already have the wood structure ready and the 125A (I think they're some kind of brass alloy) bus bars. They are advertised as (AC) ground bus bars.



Thanks for your thoughts in advance!

 

[HRTKD]

Dry wood should be non-conductive. There are a lot of us with components fastened to boards. Is it ideal? Maybe, maybe not. If you could elevate the bus bar off the wood using washers for spacers that might mitigate most heating issues. My main bus bars have a composite plastic between the metal part of the bus bar and the surface the unit is mounted on. That should help. Then again, if your bus bars are the source of enough heat to worry about, maybe the design and components are incorrect.

 

[time2roll]

That looks like a taxi not a BUS.

https://www.bluesea.com/products/1992/PowerBar_1000_-_8_5_16in_Terminal_Studs

 

[ArthurEld]

I've been trying to get away from combustible materials around my batteries.
It is so easy and cheap to work with wood.

I got used to screwing things on to my shelves and on to my fixture. And I had ideas to make busbars and BMS mounts using wood as the base.
For the most part I gave up on making my own stuff and I have been buying Blue Sea or other big names and UL listed pieces.
These cells don't burn by themselves. But they can start fires if there is anything flammable nearby.

It's a big pain in the ass but I am going to make my batteries with very few combustible pieces.

 

[HRTKD]

My current compression frame uses plywood on the ends. It was very easy and quick to do. I'm good with wood. Metal, not so much. But I'm learning to TIG weld, so maybe the compression frame will get aluminum end plates in the future.

 

[ArthurEld]

The compression fixture wood is hard to give up.

 

[jwelter99]

The compression fixture wood is hard to give up.

You can do it with aluminum 80/20 but not as compact and more work. For some stuff a sheet of plywood has no substitute

 

[time2roll]

How thick would the aluminum be vs wood?

Then do I leave it bare or what to use for insulation?

 

[HRTKD]

My guess is 1/4" aluminum plate would be good enough, maybe thinner, but not by much. The thin, flexible cutting board material would make a good layer between the aluminum plate and a cell.

 

[jwelter99]

My guess is 1/4" aluminum plate would be good enough, maybe thinner, but not by much. The thin, flexible cutting board material would make a good layer between the aluminum plate and a cell.

Might be a good business for someone with a plasma table to sell compression end plates.... definite need in the market.

 

[Semoreo]

The right wood maybe. Use some non-conductive spacers and you should be ok. Wood isn't normally conductive but you would have to be careful with moisture and condensation. Add condensation to the surface, or soaked into the wood and probably not but who knows.

 

[Gone]

HDPE may be an option.

 

[ArthurEld]

The cutting boards burn. And they might fuel a fire better than plywood.
How about high temp gasket?

Amazon.com: Lynn Manufacturing High Temperature Gasket Paper, Superwool, 2100F Rated, 1/8 Thick x 7 x 10, for Wood Stove, Pellet Stove, Boiler, Furnaces, Kiln, Forge, 2260J: Home & Kitchen

Amazon.com: Lynn Manufacturing High Temperature Gasket Paper, Superwool, 2100F Rated, 1/8 Thick x 7 x 10, for Wood Stove, Pellet Stove, Boiler, Furnaces, Kiln, Forge, 2260J: Home & Kitchen

www.amazon.com

I'm not sure what happens if these things are in a fire

Silicone - https://www.amazon.com/AmazonBasics...7&sr=1-1-fcc74f9e-0165-48d2-a9e1-f41ea92a035c

 

[Pyrofx]

I built mine like this , but with 3/8 copper

Amazon.com

 

[Gone]

I'm enclosing cells in a lined and sealed metal container to mitigate flammability concerns, but that may not be an option for some scenarios.

 

[rhino]

I'm enclosing cells in a sealed metal container to mitigate flammability concerns, but that may not be an option for some scenarios.

As long as the cells aren't directly touching the metal. There was some concerns of voltage potential between the outer casing of the cells and positive.. so some have even been putting insulating sheets between cells as well.

 

[grizzzman]

I'm building a 24V lead acid battery bank and I was going to mount both positive and negative bus bars onto the wood structure that will hold the batteries in place.
I saw a thread recently where a user shared a near disaster experience where wood planks were in contact with LiFePO4 cells. My personal and non-professional point of view is that wood should be non conductive for 12V~24V.

Should I under no circumstances screw the bus bars to the wood? You think I'm a mad man?
What would you do in my place?
I already have the wood structure ready and the 125A (I think they're some kind of brass alloy) bus bars. They are advertised as (AC) ground bus bars.

View attachment 42658

Thanks for your thoughts in advance!

You will find that its common in rv's. I myself do it. I do keep an eye on them. I guess it is an issue of risk management. You can live life or...you can fear it.

 

[markver]

I'm building a 24V lead acid battery bank and I was going to mount both positive and negative bus bars onto the wood structure that will hold the batteries in place.
I saw a thread recently where a user shared a near disaster experience where wood planks were in contact with LiFePO4 cells. My personal and non-professional point of view is that wood should be non conductive for 12V~24V.

Should I under no circumstances screw the bus bars to the wood? You think I'm a mad man?
What would you do in my place?
I already have the wood structure ready and the 125A (I think they're some kind of brass alloy) bus bars. They are advertised as (AC) ground bus bars.

View attachment 42658

Thanks for your thoughts in advance!

The ground bus you have pictured is only rated for AC ground and neutral connections in a metal enclosure or breaker box. It's only used to rout erroneous AC voltages to your system ground, typically popping a 15a or 20a breaker. They don't have a DC current rating. Better to be safe with an insulated DC rated (250a) bus bar.
https://www.amazon.com/gp/product/B07C6483RC/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

 

[Gone]

@markver, are you sure?
It seems a piece of copper with that large of a cross section should suffice.

 

[WoodsieLord]

Thanks everyone for your answers!
I'm on an extremely tight budget, so you will notice that my system is not standard, as safe as it should be, or properly sized.
I know I'm taking some risks with this. My plan is to upgrade to proper wiring and connectors as time passes and I'm able to afford them.

You will notice something quite unusual. I have a TON of small SLA batteries. These batteries were discarded at work from several big UPS once replaced. I noticed these batteries were 3 years old and almost not cycled (not many power outages and automatic backup generator that kicks in within 1 minute of outage).

I was glad to take them, despite the fact that SO MANY paralleled strings might carry some kind of unbalancing issues. I'm currently testing them to see how they do.

I've been trying to build aluminum enclosures (inspired on the emerson enclosures like this one). You can clearly see my 4 attempts in the last picture. They took a lot of time to build (I don't have proper tools) and aluminum is expensive. So I ended up building the wood structures in like 20 minutes.

Thanks markver for your input in regards to the ground bus bars I've got. I agree this is not a proper installation.

For the time being, I did a test today using a hair drier with the array disconnected, then reconnected and let them recharge. The test drew 20A from the bank and then the charger threw 20A back. My inverter supposedly handles up to 3000w but my highest usage up to date was 1200w~1400w.
I've been touching the wiring and bus bars and they remained cold.

This seems to be working. I will test the batteries a bit more. Then I will buy fuses and might replace the bus bars.



Regards!