System Placement/Safety Concerns

[JAS]

Hi all,

I'm planning on installing a small solar setup to run a few circuits in my home. I will be connecting a Samlex EVO-2224 to my existing Generator Manual Transfer Switch Panel (that is mounted right next to my home's main panel). I'm in the process of ordering/building a diy LifePO4 battery pack.

I'm concerned about the safety of placing the batteries inside my home. I understand LifePO4 is probably safer than any other battery chemistry. However, I don't expect my insurance company to honor any claims once they discover the non-UL listed batteries inside the home.

So my options are:

1. Place inverter/batteries in my detached garage. The drawback to this option is the cost in materials and labor to have an electrician run two lines back and forth from the house panel to the garage (about 100'). At this length, I would need very heavy gauge wire to handle the full potential load that the EVO can use...
2. Place inverter inside my home next to the electrical panels and run the battery cables through the wall to a box outside that houses the batteries. The drawback to this is that the battery box would be a bit more subject to temperatures and the potential for theft (although this is not a real concern to me). The Inverter is still inside the house. But, the Samlex is UL rated and I "assume" would not be an issue in regards to an insurance claim...

Would appreciate any thoughts on this?

Thanks,

Jeff

 

[Sanwizard]

I have my batteries and inverters in the Garage, just in case. The batteries are in a metal enclosure. My garage is also about 75' from the house, but that is also where I hung my solar panels.

Anything in the house should be UL listed for insurance reasons in my opinion. My inverters are, but my DIY batteries are not.

 

[JAS]

Sanwizard,

What gauge wire did you have to run between your house and garage?

 

[Steve_S]

I have a separate powerhouse but the idea is a sound one pending on situation. I also have it combined with my Pumphouse therefore I heat it in winter to 10C/50F. Now I did run my powerlines underground to home and while doing so I strung One #6/3AWG & One #8/3AWG NMWU Wire in 4" Insulated conduit so I can deliver pretty hefty AC to home if needed... It's part of the Future Proofing I did and I got a Hell of a deal on the wire to boot. Really, think about it, that's not wire to try & fish through later... let's just say "Lessons Learned" with previous construction situations.
ref: #6/3 can handle up to 55A, #8/3 can handle up to 40A, 240VAC.

You can do similar with the garage and you can even build a little "lean-to extension" if you need to insulate & heat in winter and build it all in there and run an underground VAC line to house, which is a more common approach, if in Conduit, you can also string in CAT-6 Ethernet for communications lines. (I did) IF you are concerned about Fire Safety & Such, in particular for finicky insurance, you can use Magnesium Oxide (Mag-O) 4'x8'x1/2 sheets which is Fire Rated (higher than cement fireboard) 1/2 the price of cement board, waterproof, fireproof and easy to work for cladding the walls.

Link to 2 US makers of Mag-O

DragonBoard USA - Official Site

The Official Home of DragonBoard USA. Dragonboard Magnesium Oxide Board (MgO) is a lightweight alternative to poured concrete. Dragonboard is ideal in floor applications where non combustibility and resistance to abuse, termites, fire, and mold are required.

dragonboard.com

Magnesium Oxide Drywall, Foreverboard, MgO Drywall, MgO Wallboard, Shafter, CA

We manufacture Foreverboard, magnesium oxide drywall (MgO Drywall - MgO Board), which is resistant to mold, mildew, water, fire and insects.

www.foreverboard.net

 

[Sanwizard]

Sanwizard,

What gauge wire did you have to run between your house and garage?

I just used what was there. 100amp breaker in the main box, but 60 amp in the sub panel in the garage. It looks like 3 or 4 awg. I also have a 20KW natural gas generac with a 200amp ATS feeding the main panel, and those wires look similar to whats in the Garage sub panel.

 

[JAS]

Really, think about it, that's not wire to try & fish through later...

Yeah, that's what is pushing me away from installing in the garage. I do have a 3" underground conduit between the house and the garage already. But, like you said... fishing 6/3 & 8/3 wires not only thru the conduit, but also all the way across the ceiling of my finished basement to get to the panels ? will be a royal PITA. The garage is neither insulated nor heated. So installing in there doesn't really gain me much temp stability.

My gosh, the cost of wire alone looks to be around $1000 (currently at Lowe's) . Not to mention the hours of labor paying my electrician to help me pull it.

I think I'm back to setting up a protected box out the back of the house on the other side of the wall from the electric panels. That way I can keep the EVO right next to the panels and keep the AC wiring short. The battery wires will probably only need to be about 10' to reach outside. I assume 2/0 will be OK for that length at 24v?

I'm thinking a steel job box maybe lined with some foam insulation would make for a nice battery storage box too...

 

[JAS]

and you can even build a little "lean-to extension" if you need to insulate & heat in winter and build it all in there and run an underground VAC line to house, which is a more common approach,

Steve,

So this took a while to sync in to me... Are you suggesting that I also put the Inverter outside (with the batteries & SCC)? It would drop the DC battery cable length from around 10' to probably 3'. Is there some other advantage?

 

[Steve_S]

It is quite ridiculous to run DC a long length, the line loss & deration will cost you a fortune to overcome with cable sizes, AC is used because it can run long distances. All of my gear is within the Powerhouse, SCC, Inverter/Charger Battery banks, AC from there to house.
100' of 6/3 is NOT a grand either, the Whole Roll sure but that's 100's of feet. Up here 6/3 10m long = $175 CAD or so.

 

[JAS]

It is quite ridiculous to run DC a long length

Is 10' considered a "long length"? According to Blue Sea Systems, 10' is fine at 2/0 for 24 volts... http://assets.bluesea.com/files/resources/newsletter/images/DC_wire_selection_chartlg.jpg

100' of 6/3 is NOT a grand either,

For BOTH 125' of 6/3 (AC Input) & 125' of 8/3 (AC Output) is $1000 (well $954 w/ tax to be precise).

https://www.lowes.com/pd/Southwire-Romex-SIMpull-125-ft-6-3-Non-Metallic-Wire-By-the-Roll/3129185

https://www.lowes.com/pd/Southwire-Romex-SIMpull-125-ft-8-3-Non-Metallic-Wire-By-the-Roll/3138943


I think you may have missed the part where I've bagged the idea of installing in the garage (because of wire costs and labor (both electrician and my time)) and am thinking about building a lean-to style shed/box next to the house just outside the wall from the existing panels.

The question is: Do I keep the inverter inside mounted on the wall next to the main panel or outside with the batteries and SCC in the lean-to?

Inside: Inverter stays in a temp controller environment (although I know the Samlex can handle cold temps). Otherwise, the only difference is if I run 10' of battery connect cables through the basement wall or (2) 10' AC lines (might as well do both 6/3 at this short of length)?

 

[Steve_S]

It could be either or, up to you, if you'll be warming the lean-to shed (hopefully on the Shady side of the house) then you won't have an issue. As I said, I keep my powerhouse at 10C/50F in winter but it is also hyper insulated with thermally broken walls and Frost Protected Slab Foundation, very similar to my house. All of my walls are solid core foams.

 

[rhino]

I'm thinking a steel job box maybe lined with some foam insulation would make for a nice battery storage box too...

If you are already concerned about fire do not use foam since it will contribute to fire spread and/or generate lots of toxic smoke.. One option if you need some extra insulation is mineral wool/rockwool boards which will not burn... it is also sold as acoustic sound absorber panels but is same thing. Trouble might be finding any stock of it because of the housing boom.

 

[Sanwizard]

It is quite ridiculous to run DC a long length, the line loss & deration will cost you a fortune to overcome with cable sizes, AC is used because it can run long distances. All of my gear is within the Powerhouse, SCC, Inverter/Charger Battery banks, AC from there to house.
100' of 6/3 is NOT a grand either, the Whole Roll sure but that's 100's of feet. Up here 6/3 10m long = $175 CAD or so.

Yup. My battery to inverter cables are about 4 feet.

 

[JustPractical]

If the batteris are mounted ioutside in a cold climate, won;t there be charging problems when things get very cold?

 

[rhino]

If the batteris are mounted ioutside in a cold climate, won;t there be charging problems when things get very cold?

Yes, that is why those that have done this have made sure to help keep the batteries warm... A super insulated room/building for instance with small heater.

Granted, you have 100% guarantee of not burning your house down if it isn't inside your house but we really don't have good understanding of what the true risk actually is. All these power walls and other commercial systems are being placed directly inside houses. People always hear about the "catastrophes" and not all the ones that never have issues or even what the root cause of the catastrophes are. I've seen some really poor installation practices which is not a surprise when something happens.

To put in perspective:

Municipal fire departments in the US responded to an estimated annual average of 48,530 home structure fires caused by heating equipment in 2014–2018. These fires resulted in an estimated 500 civilian deaths; 1,350 civilian injuries; and $1.1 billion in direct property damage each year.

Failure to clean equipment was the leading factor contributing to home fires involving heating equipment and accounted for a quarter of all the heating equipment fires. Most of these fires were confined fires, which limited the associated losses, as indicated in Figure 6. Fires in which a heat source was too close to combustible materials were far more likely to spread beyond the object of fire origin and were associated with the largest share of civilian deaths and injuries, as well as direct property damage.

In other words, user error. Why would the same trend not be the same for DIY batteries when you see some very poor practices done in some of these DIY builds.

 

[JustPractical]

Rhino - I agree some fires can be the result of user error. Until I saw this thread, it had not been in my mind that fire could be a problem. I understand the fear of a "non-UL rated device" being found to have caused a fire. That would not be fun.
I live in a cold climate - I would run my batteries down just running the heater to keep them warm each day.
I'm going with "hope for the best, but put up fire rated sheetrock above and behind the batteries.