Custom Wood Battery Rack for 16 x Pylontech US5000 Off Grid

[AlaskanNoob]

Fire isn't a worry as much because this particular install is keeping the batteries basically underground in a structure that is separate from the house.

Old concrete form boards work good but I'm a fan of old pallet racking or a new smaller pallet rack like Costco sells.

Yeah, but if caught fire it would almost certainly burn down the solar shed and everything in it and depending on the wind and season it might start a forest fire that would burn down our cabin and be much worse.

Again, I'm banking on these systems working properly as advertised given I don't think there is a cost effective way to protect from fire. The temps I've seen are so hot that I don't think there is much that can be done if they go blazing.

What are these pallet boards? Are they better than those cement mesh boards?

 

[AlaskanNoob]

My batteries are in a wood shelf "rack" and the batteries are warm to the touch, but not hot. Maybe it will be different in July. The heat comes from the inverter. Metal has its downside as well.. it conducts.

I've never noticed our batteries even being warm. And the internal temps don't seem to really rise much either, although I did notice when they were getting hours of 7KW of charge coming in that they did increase the internal temps. Although sun hitting the metal siding on the shed may have been part of that.

 

[AlaskanNoob]

Hopefully this base made from 3" x 3" lumber will be enough to hold the 1400 pounds of batteries up. I suppose I might need some kind of cross bracing on the base though.

 

[AlaskanNoob]

We probably want to buy a shielded CAT5 cable for going from the master battery to the Cerbo. And then will drill a separate hole in the top for that cable. The 16 4/0 cables will go through that shown hole up top. I'll foam that hole after getting the cables set to trap heat in.

When we had the system go offline a few weeks ago it was because the master battery stopped communicating with the Victron equipment (which made the inverter and MPPT ignore the batteries) which I think was because my battery Cat5 cable was touching one of the power cables and zapped that batteries comm port. Don't want that to happen again...

 

[Checkthisout]

We probably want to buy a shielded CAT5 cable for going from the master battery to the Cerbo. And then will drill a separate hole in the top for that cable. The 16 4/0 cables will go through that shown hole up top. I'll foam that hole after getting the cables set to trap heat in.

When we had the system go offline a few weeks ago it was because the master battery stopped communicating with the Victron equipment (which made the inverter and MPPT ignore the batteries) which I think was because my battery Cat5 cable was touching one of the power cables and zapped that batteries comm port. Don't want that to happen again...

Can you weld?

 

[AlaskanNoob]

Can you weld?

Of course I can, I have YouTube! I bought a welder but have never used it (turns out it wasn't powerful enough for the reason I bought it). I haven't welded anything since the 7th grade in shop class, and I remember the teacher wasn't overly impressed with my work.

But I have a Wood Mizer and tons of wood also.

 

[AlaskanNoob]

I wonder what kind of bracing would be better...

Something like this:

Or something more like this?

 

[CaliSunHarvester]

I wonder what kind of bracing would be better...

Something like this:
View attachment 201599
Or something more like this?
View attachment 201600

I would just put a 2x6 or 2x8 over the full length upright against the "posts". Both front and back.

Half way up between bottom and first shelf.

 

[CaliSunHarvester]

Here is a photo of my own battery rack, I see no problem with 5 stacked on top of each other.

I normally build a lot with steel, using tubes and wide flange i-beams, but from a 2022-23 project, I have a LOT of lumber.. it was used to build concrete forms and cost over 20k. Lumber price fell a lot here, worth 12k now I guess.

The sander in the photo.. necessary because to clean it up after being used for the forms.

 

[Checkthisout]

I wonder what kind of bracing would be better...

Something like this:
View attachment 201599
Or something more like this?
View attachment 201600

No. Just use 3/4 plywood on the back for shear.

Leave yourself more room to access the tops of the batteries.

Your drawing lacks details showing connections etc.

Also, please use off the shelf bus bars with each battery fused where it connects. Do not use copper with standoffs or something like that.

 

[Checkthisout]

Of course I can, I have YouTube! I bought a welder but have never used it (turns out it wasn't powerful enough for the reason I bought it). I haven't welded anything since the 7th grade in shop class, and I remember the teacher wasn't overly impressed with my work.

But I have a Wood Mizer and tons of wood also.

Well ok. Just take your time and use thick material.

 

[AlaskanNoob]

Well ok. Just take your time and use thick material.

Shelves are 2" thick. All the posts are 3" x 3". You think plywood to cover the base is better than using 3x3 diagonal bracing (this just shows the front, I'd also do the back)? It would be easier to just use plywood.

 

[AlaskanNoob]

No. Just use 3/4 plywood on the back for shear.

Leave yourself more room to access the tops of the batteries.

Your drawing lacks details showing connections etc.

Also, please use off the shelf bus bars with each battery fused where it connects. Do not use copper with standoffs or something like that.

The bracing is just the bottom part. The shelves with the battery are up top and will be accessible. I already have the batteries hooked up and I've got the connections working and the bus bars and fusing and such. I'm just trying to design a more robust shelf that I can more easily insulate than the ones I'm using now.

 

[Checkthisout]

The bracing is just the bottom part. The shelves with the battery are up top and will be accessible. I already have the batteries hooked up and I've got the connections working and the bus bars and fusing and such. I'm just trying to design a more robust shelf that I can more easily insulate than the ones I'm using now.

My bad. I was picturing diy batteries!

 

[AlaskanNoob]

For the base I might actually use 4"x4" pressure treated lumber. Then mill 3x3 for the shelf lumber.