max. allowed LFP battery storage in attached garage with A/C and smoke detectors

[fmeili1]

HI,

I've tried to find out the current code status situation, but I'm a bit lost.

Environment:

• Attached RV garage to a single family home (house/garage built 3 years ago)
• The RV garage is air conditioned.
• The batteries are in two separate server/battery racks (max. 6 batteries each) with a distance of about 5 feet between the two racks.The racks have swiveling casters (2 with breaks).
• The racks are on an inside drywall between garage and house
• cement board is mounted between drywall and server racks
• 2 smoke detectors are located on the (high) ceiling over the wall where the battery racks are located. The smoke detectors are interconnected and in case they trigger, they disconnect both battery racks from the AIO's (via two 600A relays)

Some sources talk about a max. of 40kWh others about max. 80kWh. Others source talk about smoke and/or heat sensor need to be installed if the capacity is between 40kWh and 80kWh. I can't find any hint about possible differences of LFP/LiFePO4 batteries compared to the more fire risk other lithium based batteries. Some sources talk about a max. of 20kWh per individual storage unit which needs to be placed 3ft from each other.

So I'm still not sure what are really the rules here?

What is the max. allowed number of 48V/100AH (5kWh) LFP batteries in total? How many of these batteries are allowed to place per rack? Can I use more batteries if the space has A/C? Can I used more if I have smoke detectors? Is there still no difference between LFP and other chemistry? Each battery "EG4-LL (V2)" has a label showing 5.1kWh - I think for marketing reasons calculated with more than 48V - I hope they will be treated as 5kWh when final inspection occur.

Is it allowed to leave the swiveling casters on the racks? Because the racks standing on the floor, what's about the minim distance between the floor and the lowest battery space?

Because the racks are located an the back (small) wall on the RV garage, is a impact/bump protection required (e.g. a car/RV may hit the battery racks)?

Maybe someone could shed a bit of light in these questions.

 

[DIYrich]

I'm doing this from memory, so I might be off, but it goes something like this.

UL 9540 requirements:
1) Any single rack of batteries cannot exceed 20kWh.
2) Racks of batteries have to be separated by 3 feet.
3) Any single location cannot exceed 40kWh.
Locations are: Inside, Garage, Outside (total of 120kWh per house).
Don't know if a detached "battery shed" is included in the "outside" total.

Don't know about the rules regarding impact or bump protection, but my guess is that if a vehicle can get close to it, then it has to be protected from impact.

Rule doesn't differentiate between battery chemistries.

 

[Oldphile]

Also be aware of where the batteries can be located in a garage.

 

[fmeili1]

Also be aware of where the batteries can be located in a garage.

So it looks like I need at least two bollards in front of both racks when the battery racks are located at the back wall of the RV garage.

I found these bollards and hope they will be accepted (36" height) when placing it where the two red crosses are marked in the picture.

 

[Oldphile]

So it looks like I need at least two bollards in front of both racks when the battery racks are located at the back wall of the RV garage.

I found these bollards and hope they will be accepted (36" height) when placing it where the two red crosses are marked in the picture.

Some folks in MA were required to open the floor and embed bollards in concrete. Bolt down was unacceptable. Your AHJ may not be so strict.

 

[petee_c]

We have 158kWh of battery in our garage.... no one's said anything about it. Insurance knows.

2023 BMW i4M50
2023 Genesis GV60

 

[Tmoney2007]

Some folks in MA were required to open the floor and embed bollards in concrete. Bolt down was unacceptable. Your AHJ may not be so strict.

That's what they're telling me in Texas. 4" steel pipe with a 15" footing embedded 36" into the ground.

The real kicker is that they're saying that the bollards have to be 36" away from the batteries themselves. They're also sticking to the 20kWh per pack.

 

[Liam M]

So it looks like I need at least two bollards in front of both racks when the battery racks are located at the back wall of the RV garage.

I found these bollards and hope they will be accepted (36" height) when placing it where the two red crosses are marked in the picture.

View attachment 192191

You’d want to check with your AHJ regarding questions of what will be accepted.

 

[Liam M]

That's what they're telling me in Texas. 4" steel pipe with a 15" footing embedded 36" into the ground.

The real kicker is that they're saying that the bollards have to be 36" away from the batteries themselves. They're also sticking to the 20kWh per pack.

If a 36” bollard is hit by car and knocked over, the bollard potentially impacts the batteries if <36”

 

[fmeili1]

If a 36” bollard is hit by car and knocked over, the bollard potentially impacts the batteries if <36”

If the bollards are positioned on the side of the racks (about some inches from the side wall) they would not be able to impact the batteries...

 

[fmeili1]

We have 158kWh of battery in our garage.... no one's said anything about it. Insurance knows.

2023 BMW i4M50
2023 Genesis GV60

Yes this is crazy. The solar LFP batteries are much more safer and smaller compared to the typical EV car batteries but the rules for ESS are much more restrict compared to EV's...

 

[Tmoney2007]

If a 36” bollard is hit by car and knocked over, the bollard potentially impacts the batteries if <36”

A 36" bollard sunk 36" into the ground is not likely to be knocked over by a vehicle traveling at a reasonable speed for pulling into a residential garage. At some point you have to be realistic about your scenarios.

Its infinitely more likely to be backed into at low speeds and that's not terribly likely. I can also put them immediately outside the garage and be within code, despite the fact that given a tractor trailer moving at highway speeds, it could demolish the entire garage and push the battery into my house.

 

[fmeili1]

I'm doing this from memory, so I might be off, but it goes something like this.

UL 9540 requirements:
1) Any single rack of batteries cannot exceed 20kWh.
2) Racks of batteries have to be separated by 3 feet.
3) Any single location cannot exceed 40kWh.

I found this document (specific to California) which states in section R328.5 that it's allowed to install 80kWh total ESS in attached or detached garages (but still not more than 20kWh per ESS unit).
I've heard a lot of times that California rules are usually very tight in regulation, so I wonder if this may also be valid for other states?

Locations are: Inside, Garage, Outside (total of 120kWh per house).

If I understand right, it would be possible for a single family home to place e.g. 40kWh in a garage (with two 20kWh units, 3 feet distance), place additional 2x20kWh units e.g. outside of the house and a 3rd 2x20kWh inside of a storage to achieve the 120kWh maximum?

 

[petee_c]

I'm doing this from memory, so I might be off, but it goes something like this.

UL 9540 requirements:
1) Any single rack of batteries cannot exceed 20kWh.
2) Racks of batteries have to be separated by 3 feet.
3) Any single location cannot exceed 40kWh.

I've been researching the ESA (Ontario, Canada - Electrical Safety ) and they also follow the UL9540, and these same rules.

 

[SeaGal]

The solar LFP batteries are much more safer and smaller compared to the typical EV car batteries but the rules for ESS are much more restrict compared to EV's

So if you have a V2H connection and your EV becomes your ESS, do you have to put bollards around it to stop your other car crashing into it?