Making an elevated wood shelf to hold up 1400 pounds of batteries...

[AlaskanNoob]

So we've got our 8 Pylontech batteries in our solar shed which is located above a root cellar. Turns out the Alaska winters laugh at my attempt to insulate the batteries. So I'm going to move them down into the root cellar with room to double them, into a super insulated wood shelf.

The shelf will sit on a concrete floor in the root cellar and will hold the batteries a couple feet off the ground close to the ceiling of the root cellar, which is the floor of the shed, to shorten cable lengths going to the bus bar on the wall in the shed above.

Four shelves that will hold four batteries each, so each shelf will need to hold 352 pounds or so. The total will be 1408 pounds or so.

Will spray closed cell foam around the outside to super insulate it and have doors with hinges for access.

Thinking the base will be a rectangle with a support in the middle as well with blocking in the middle of each shelf to help support the shelves.

Thinking the base will have diagonal supports on three of the four sides, so the space under it can be used for storage.

Recommendations on the design? Thickness of the wood shelves or the base?

 

[aenyc]

Dont forget ventilation. I hope your batteries are LFP, but even in that case you have to account for some interesting fire suppression mechanisms (with the only really realistic one being building this at some real distance)

 

[AlaskanNoob]

Dont forget ventilation. I hope your batteries are LFP, but even in that case you have to account for some interesting fire suppression mechanisms (with the only really realistic one being building this at some real distance)

They're LFP so I'm not putting any fire suppression mechanisms in at the moment. I'll put fireboard on the ceiling but I haven't seen any practical fire suppression solutions.

What are the ventilation requirements all about?

 

[aenyc]

They're LFP so I'm not putting any fire suppression mechanisms in at the moment. I'll put fireboard on the ceiling but I haven't seen any practical fire suppression solutions.

What are the ventilation requirements all about?

I am pretty sure that the batteries need decent ventilation to operate properly. Every commercial UPS facility that I have seen has decent airflow system.

 

[AlaskanNoob]

I am pretty sure that the batteries need decent ventilation to operate properly. Every commercial UPS facility that I have seen has decent airflow system.

Is that for cooling or for venting some kind of off gas?

The manual is somewhat ambivalent on it and says:

There is no mandatory ventilation requirements for battery module, but
please avoid of installation in confined area. The aeration shall avoid of high salinity, humidity or temperature.

The foam should prevent the humidity from the root cellar from getting in there. In the summer I'll probably leave the door open for cooling though.

I'm curious how beefy I need to make the wood to handle the weight though. I'm not a woodworker just as I'm not an electrical engineer, so I really have no idea how big of beams and shelves I should use. I have no idea how to even calculate. I may have to just go with the TLAR method.

 

[aenyc]

Is that for cooling or for venting some kind of off gas?

The manual is somewhat ambivalent on it and says:

That i am not sure, but basic aeration seems like a given. As i said my experience with commercial battery systems has been that they are all well aerated (i.e. moving air usually by means of powerful AC but the scale is much larger than your system)