800 lbs of batteries over floor joists

[mr person]

Looking at these silicate batteries. 98 lbs each, and 8 batteries.

14.4kWh- Silicate Battery 12/24/48V Best Price per kWh – 15 yrs -6000 Cycles at 30% DOD 8 yrs -3000 at 60% – Temp -40F to 150F. NO BMS or Thermal Protection required, Non Corrosive, non explosive, perfect solution – Watts247 Wholesale

watts247.com

I really dont see a way to make this work inside the house unless I spread them out from each other which would take up way too much floor space.

It appears each battery takes up just over 2 sq ft, which would be about 50lbs/sq ft, so considering houses are built to support 30-50lbs/sq ft, these might work as long as they were not stacked (e.g. in a cabinet), but I really dont have 16 ft of floor space in my house

Dont want to keep them in garage either cause it gets at -15F or more sometimes.

Any ideas?

 

[42OhmsPA]

What's under the floor they would be sitting on, could you add additional support below?
Plating to spread the load over more joists?
Hang them from the ceiling ?

 

[BartHenry]

Use a pice of 3/4" plywood under them. That will distribute the weight more evenly.

 

[Kornbread]

Not all houses are built the same but yeah, I'd consider pouring a pad outside and building a small solar shed.

 

[mr person]

Use a pice of 3/4" plywood under them. That will distribute the weight more evenly.

Well, that still doesnt escape the total weight over given area given my scenario, so doubt that's helpful unless it extends a bit beyond the battery edge, which will only help a tiny

 

[mr person]

Not all houses are built the same but yeah, I'd consider pouring a pad outside and building a small solar shed.

I have a cement back porch, but yeah, its super cold here. If going that route, might as well put in garage where at least its warmer.

 

[mr person]

What's under the floor they would be sitting on, could you add additional support below?
Plating to spread the load over more joists?
Hang them from the ceiling ?

1. Under floor: Guess I might need to hire a builder to make that happen. Not sure where to do it myself.
2. Plating: sounds like you mean metal plating, but sounds similar to plywood. Again, 1 battery alone is almost too much weight, so no way to save any floorspace by doubling up and putting plating under everything.

I'd upload a photo of my mudroom where I really want to put it, but you prob get the idea. Maybe I could cover them with benches for sitting....hmmmm

 

[SamDeleted]

Put them at the side of the room, the floor joists might not be able to take the weight smack in the middle , but I'd bet money they'll handle it if you put the batteries right next to the load bearing wall

 

[SamDeleted]

I've just put 600lb of battery in my shed, the floor joists are 2x4s (yours in your house will be 2x6 or even 2x8)

My shed floor handled it no probs, because I put the batteries right in the corner near where the joist sit on the concrete foundation block. If I'd put them in the middle the floor it would've sagged

Don't forget these are dead weight.

Dead weight (eg. batteries) is much easier to support than live weight (like people jumping up and down)

800lb that's only the weight of 4 normal men (or 2 big fatties lol) it'll be fine don't worry about it ?

 

[mr person]

To start sort of a side-thread, is there a way, and does it make sense, to heat a cabinet to keep batteries warm? Seems like that would cost a lot of power over time, along with safety issues.

 

[SamDeleted]

To start sort of a side-thread, is there a way, and does it make sense, to heat a cabinet to keep batteries warm? Seems like that would cost a lot of power over time, along with safety issues.

The lads on here use thin low powered heating wires straight off the batteries. Someone more clued up than me could explain, or might be worth having a good search of the forum

 

[mr person]

I've just put 600lb of battery in my shed, the floor joists are 2x4s (yours in your house will be 2x6 or even 2x8)

My shed floor handled it no probs, because I put the batteries right in the corner near where the joist sit on the concrete foundation block. If I'd put them in the middle the floor it would've sagged

Don't forget these are dead weight.

Dead weight (eg. batteries) is much easier to support than live weight (like people jumping up and down)

800lb that's only the weight of 4 normal men (or 2 big fatties lol) it'll be fine don't worry about it ?

I was looking at this:

4-Tier Welded Steel Garage Storage Shelving Unit (48 in. W x 72 in. H x 18 in. D) - Supports 2000 lbs per shelf

Batteries: Length 19.02 inches, Width 16.69 inches, Height 9.45 inches

Rounded: 20 x 17 x 10

So, this means I could prob put 2 batteries on each shelf or 3 in the other direction if they stuck out a couple inches, making it:

800 lbs over 6 sq ft, or 133 lbs/sq ft

Seems like a lot for any floor

 

[mr person]

The lads on here use thin low powered heating wires straight off the batteries. Someone more clued up than me could explain, or might be worth having a good search of the forum

Heating seems like a risky proposition as well, esp if you get a warm day or two and arent the type to want to check equipment every day, nor depend on electronics to always be reliable.

 

[SamDeleted]

Seems like a lot for any floor

I wouldn't worry too much about all the mathematics . This isn't an electrical problem, this is a carpentry problem. Carpentry is not an exact science. All those maths figures you posted about the weights the floor can take are estimates at best.
every piece of wood is unique it has different structural qualities , one 2x4 can be much stronger than another.

I could go on but long story short. the floor can either take the weight or it can't .... Get a couple of fat mates round and jump up and down on it ! You'll soon find out if it's strong enough

 

[SamDeleted]

Heating seems like a risky proposition as well, esp if you get a warm day or two and arent the type to want to check equipment every day, nor depend on electronics to always be reliable.

I think they're usually on thermostats, but yes I agree . Thankfully not a problem where I am it doesn't normally get cold here

 

[TorC]

If you're right next to a load bearing support underneath, don't worry about it. If you've got 2x4 joists, then maybe add a few diagonal braces down to the girder, but other than that, you probably can't get in trouble.

As alluded to above, an 10x12 room at 40psf is calculated to take a load of 4800lbs distributed. Right over the supported end of the joists you've got almost no load on most of the floor — the back of your shelf basically loads only the girder underneath just about taking half the batteries off the floor entirely.

If you want further peace of mind, try giving us a couple pictures of the underside of the floor where you would like to put the batteries.

 

[42OhmsPA]

I was looking at this:

4-Tier Welded Steel Garage Storage Shelving Unit (48 in. W x 72 in. H x 18 in. D) - Supports 2000 lbs per shelf

Batteries: Length 19.02 inches, Width 16.69 inches, Height 9.45 inches

Rounded: 20 x 17 x 10

So, this means I could prob put 2 batteries on each shelf or 3 in the other direction if they stuck out a couple inches, making it:

800 lbs over 6 sq ft, or 133 lbs/sq ft

Seems like a lot for any floor

I'd put a sheet of plywood or steel down to disperse the load, especially if you plan to use a shelf. The legs of the shelf will be putting a lot more pressure in small areas than the footprint of the batteries.
Heck even a couple rough cut 2x10s glued and pocket screwed together to make a 20" wide plank would work out nicely I bet..

 

[mr person]

Update on battery. Seems I was listing a model that didnt actually come with kit (although I could still use it. Here is kit battery:

Length 20.86 inches
Width 10.70inches
Container Height 10.62 inches
Approx Weight 161 lbs

So 8 of these in all.

If 2 per shelf, then thats:

320 x 4 = 1280 lbs

So divided between 6 sq ft, thats 213 lbs per sq ft

Yes, plywood/steel under it also makes sense, and near the wall, but 213 pounds is 4x the recommended limit. Esp, true considering weight of entire shelf.

 

[SamDeleted]

I found this one line might be relevant:

 

[TorC]

You're too hung up on PSF loading. Stop it. The PSF loading of the floor as a whole is irrelevant except insofar as it relates to the total load in the room. Picture a 300lb fatso walking through the room. Each time he steps, he's got all 300lbs on less than half a square foot of floor, or something like 600psf. There's no problem with this.

The only point load that matters is if you've got a really heavy load situated in such a way as to put all the strain on one or two joists, and even then it's still mostly only an issue if it's nearer the middle of the floor. That's because a point load in the middle consumes the available strength of the framing somewhat faster than a distributed load.

Do you know if the wall you'd like to put the batteries along has the ends of the floor joists, or is it a (likely) double bearing joist on the wall? If the former, you're fine. If the latter, you might want to double one or more of the joists that will bear the load. Measure, go to the lumberyard, buy the 2xX, cut to length, fit in place (you might have to cut it short, but this is fine, as you won't crush the existing joist end) and nail it well along the top and bottom - every 6-12".