Shunt snapped and caused a fire🔥

[Brett V]

No compression just taped it I'm thinking don't need to bother with compression. Need to figure out how to give it enough room to expand.

The battery on wheels had some compression, everything else I’ve built wad simply wrapped tightly with filament tape. I saw no advantage to doing compression on the cells.

 

[k490]

The battery on wheels had some compression, everything else I’ve built wad simply wrapped tightly with filament tape. I saw no advantage to doing compression on the cells.

I have a box drawn up smaller then I thought it would I gave extra room came out to 36" wide 24" deep and 18" high. That will hold 2 rows of 8 each comes out to 16 EVE280 batteries. Amazing how compact these lithium batteries are. The lid will hang over little Il probably go 25 deep on the lid. Ill weld in 2x2 box tubing in the corners. I already have some 6" casters can hold up to 1000 lbs. Ill reply back on the total cost of the box and some pictures on another thread if anyone else wants to do the same. I know it's way overkill it's also piece of mind if you put these in your home don't want to be 2 hours away and your pets are inside a home burning down.

Got a quote back going to weigh 120lbs in 11G steel for the box lid is heavier 50 lbs cost is $251 total. 50 lb lid might have to rethink that probably drop it to 11 gauge 3/16 plate steel lid 50 lbs.

 

[Daddy Tanuki]

Would you agree that DALY is probably the most counterfeited BMS out there? It seems there are more knock offs than genuine products on Ali and people reporting problems don’t have a DALY at all.

probably I know that 3 of mine are DALY for a fact, the other 3 I would have to look closer at.

 

[Hedges]

Went to my local steel supplier they are going to give me good price on 1/8" plate steel shear cut everything for free. I just need to come up with a box design. I have some ideas I want to put it on casters my shed has a concrete floor. I also want the top and front to hinge open so I can gain access to slide cells toward me one at at time. Going to run a 6" stove pipe out the back and turn 90 degrees go up through the roof. I want it to be strong enough to withstand every cell burning up into a blob and when it's done I can shovel it into a trashcan and start over. 1/8 is .125 thickness I might make the top 3/16 .188 thick. I'm still going to use Class T fuses right off the battery bank, and heavy 4/0 wire. In theory my wood stove should never get hot but if it ever does It will contain it.

An opportunity for combined cycle, maybe also cogeneration?

The lid will hang over little Il probably go 25 deep on the lid. Ill weld in 2x2 box tubing in the corners.

Make it 3R, so if rolled outdoors it will keep the rain off?

I've got a small chest freezer outside, and had to thaw the glacier to extract food containers.
Also a side-by-side, which had icicles inside.

 

[k490]

An opportunity for combined cycle, maybe also cogeneration?




Make it 3R, so if rolled outdoors it will keep the rain off?

I've got a small chest freezer outside, and had to thaw the glacier to extract food containers.
Also a side-by-side, which had icicles inside.

We never have ice here hardly any rain were already hitting mid 80F here. I'm sure by March we will see 90F. Steel box outside will turn into an oven I could bake in. Was in my attic over the weekend it was 86F outside took my IR gun up there read 115F inside of the plywood. I think asphalt shingle roofs multiple the heat I'm surprised plywood is able to withstand the summer heat here. I need to take a reading when it's 119F outside it has to be up to 130-140F up there. Good reason to put solar panels on the roof my wife doesn't like the look of it.

I'm just planning on the worst outcome no matter how low the chance is.

 

[Hedges]

You may not want to use it in outdoor environment, but my suggestion since you're designing the box is to make it rainproof (and on wheels) so you can stash it outside if desired without it getting filled up with water from rain. That probably means a lip on top, any feed-throughs are gasketed and have a drip loop, any vents (besides under the lid) are either louvered or on the bottom.

 

[robbob2112]

We never have ice here hardly any rain were already hitting mid 80F here. I'm sure by March we will see 90F. Steel box outside will turn into an oven I could bake in. Was in my attic over the weekend it was 86F outside took my IR gun up there read 115F inside of the plywood. I think asphalt shingle roofs multiple the heat I'm surprised plywood is able to withstand the summer heat here. I need to take a reading when it's 119F outside it has to be up to 130-140F up there. Good reason to put solar panels on the roof my wife doesn't like the look of it.

I'm just planning on the worst outcome no matter how low the chance is.

Steel box painted white on the outside - with some sort of shade built over it to never get direct sunlight but allow airflow.

SOK has an outdoor using I was looking at - takes 12 rackmount batteries and has places for heating and cooling adapters. There seems to be a spot to hang AC on the outside if you really need it. Price is similar to what a regular server rack is, but is specifically designed for batteries.

12-Slot Outdoor Insulated Battery Rack - Fits SOK & EG4 Batteries

This new SOK 12-slot rack has built-in slots for heaters and/or AC units, allowing for easy control of the temperature inside the rack. With a sturdy design, it is easy to attach inverters on the outside for easier installation. Specifications: Outdoor rated enclosure (NEMA 4) that holds up...

www.currentconnected.com

I've seen a youtube with a guy that is taking these + batteries + Sol-Ark 15k hanging on the outside - basically is plug-n-play where you just run conduit for the wires from the main house panel and PV bank equipment.

 

[tevake]

I got the impression they must have a 300A version since that 50A one doesn't look like what is shown in the burnt pictures.

In any case I would not trust a critical piece of your power system that all power in your system goes through to some not well known Chinese brand.

I use American made Balmar SG-200, with Bluetooth. More expensive. Don't buy anything direct from China.Study MarineHowTo on shunts.Shelves should be metal, or real wood . (boat builder since 1976)

 

[gotbeans]

Thanks for the extra pictures.. couple questions, why are there alligator clips on all those cells? also is there some insulation between the cells?

In any event even if those shelves are rated for the weight you had on them I would never trust particle board for something like that. It is not a stable "wood" and can easily warp especially when exposed to moisture. If it warped at all it would cause the collapse of the shelf.

Yea for those shelves you can buy like my picture
but also I weld a nice bar or multiple bars across the bottom for strength. At least want to be able to support 4 times the battery weight if it's gonna sit there for years and years and years

When looking at the picture from the above #17 posting, it seems that the particle board under the battery
was holding the weight only on its edges and get warp and could not handle the weight of the battery.

A single 280 AH LiFePO4 prismatic cell weight about 5.5 kg or 12 lbs.
So a 48V battery with 16 cells will weight about 88 kg or 195 lbs.

View attachment 197741

I recently build a rolling cart shelf to hold and carry my batteries,
and I was worried about having a single piece of particle board could handle such weight
even if the manufacturer (The Muscle Rack) was advertising 800 lbs. per shelf.
Maybe the 18-gauge steel frame would, but not the particle board shelves.


So I started looking in another direction, and found some racks with wire shelves:
Those shelves (Husky Rack and Wire) (Gladiator) (DeWalt) can be found in majors stores,
like Home Depot, Costco, Wal-Mart..

I bought a 4-Tier rack (36 in. W x 72 in. H x 18 in. D) but I used only half of the height
to make a 3-Tier rolling cart (36 in. W x 36 in. H x 18 in. D) that I bolted on top of a
platform with 5" swivel casters, so I can easily move around two 48V 16 Cells batteries.

Each battery has its own T-Fuse, Nader 200A Circuit Breaker with Enclosure, and Anderson connector.
In case of a problem, the batteries could be moved quickly outside, or if they are installed outside of a house,
they could be moved back inside for doing some temporary service work.

View attachment 197746View attachment 197747

yep pretty spot on. We have hundreds of these shelves in our warehouse and the particle board ones. It's the same design one with mesh metal vs particle board.
You can see both are supported only on the edges by basically sheet metal. The full metal ones have doubled up lines for strength but if you're holding dangerous stuff I still weld an extra bar under it

 

[Daddy Tanuki]

i just built my rack out of 2" angle iron welded together with 1" plywood for the shelf. I put two crossbars across the longest side for extra strength.

 

[robbob2112]

Looking at

https://www.currentconnected.com/product/sok-12-slot-outdoor-battery-rack/

it looks like it takes a standard telecom environmental control per door cutout

Something like this - I would bet SOK has something spec'd out that is industry standard

Outdoor Cabinet Heat Exchanger | Air-air Heat Exchanger| LXRJH-06 | LongXing

LongXing LXRJH Series heat exchangers can be widely used in enclosed area for climate control, such as wireless communication cabinet, battery cabinet,industry control cabinet etc

www.lxtelecom.com

 

[SilverbackMP]

I like crinkle finish

Circling back on this. Sprayed BM Fresh Start Primer and then three coats of Command on a section of my plywood walls with fine finish tips. Sanding between each. No crinkle. One little section I screwed up with runs…so it got four coats. Now looks like a factory lacquer cabinet finish.

 

[k490]

I got the steel box done lot of lessons learned working on wiring it. Didn't come out as nice as I wanted if I were do it over again just buy a DIY box with a BMS from China have it shipped. I do have enough room to fit another 16S set of batteries I almost pulled the trigger on another set or 280ah for $900 but decided I spent enough for 2024 on Solar. Compressing with 1/4 thick steel and .120 wall steel tubing welded to the plate steel one threaded rod in the middle. The 1/4 steel plate is so heavy and the box tubing welded to it not sure it will need 2 threaded rods on both sides. I don't plan on compressing to the 600 lbs just want it to stay n place so the busbars don't move.

 

[robbob2112]

I got the steel box done lot of lessons learned working on wiring it. Didn't come out as nice as I wanted if I were do it over again just buy a DIY box with a BMS from China have it shipped. I do have enough room to fit another 16S set of batteries I almost pulled the trigger on another set or 280ah for $900 but decided I spent enough for 2024 on Solar. Compressing with 1/4 thick steel and .120 wall steel tubing welded to the plate steel one threaded rod in the middle. The 1/4 steel plate is so heavy and the box tubing welded to it not sure it will need 2 threaded rods on both sides. I don't plan on compressing to the 600 lbs just want it to stay n place so the busbars don't move.

Pictures or it didn't happen, maybe a build thread over in show-n-tell?

 

[doubledutch]

Great the OP shares a lot of important information here regarding fire risk. Many thanks for that!
Here my system runs on 2x18 pcs EVE LF280K in wooden boxes.
Since I bought extra cells to create a 4p18S setup I planned to weld a steel rack with drawers in it.
You can keep the height low and store a lot of power into a lower height.
These drawers have hinges (extendable ball rollers) and can extend their own lenght outside the closet/rack.
Each set is ready for 250 kg's so enough for a 100 kg 18S string.
Very handy for maintenance too.

I will also include an aerosol extinguishing system (https://www.afxfiresolutions.com), two fireballs above he cabinet and place all in a fire resistant plated closet.

I use an XT4N ABB breaker , each pole pair one string, but ABB states they need two polepair for safe DC disconnect of up to 250V DC.
Since I use about 1/4th of the voltage, I asked them to check out if this is allowed.

now I want to combine a blade fuse (160 Amps - 50kA disconnect capacity) in each string of 18 cells, in series with a DC breaker.

Can anybody advise in what DC switch/contactor to by?
The american brand is nt sold here and Tyco EV200ANAAA vacuüm relays are the next option.

My BMS is the 123smartbms one, made in the netherlands.
They only work on root-level programming in the Victron cerbo, where I would like a CAN based BMS like the REC.
The bleeding with resistors doesn't appeal to me however, their pricing neither...

 

[OffGridForGood]

Potassium Hydroxide. Interesting.
www.youtube.com/watch?v=OPsDNdRNaHw

 

[Brucey]

Can anybody advise in what DC switch/contactor to by?
The american brand is nt sold here and Tyco EV200ANAAA vacuüm relays are the next option

Not sure if you can have someone in US send you some of these, huge savings over new:

https://batteryhookup.com/products/9-36v-bms-upgrade-to-500a-relay-fuse-kit

 

[Daddy Tanuki]

Not sure if you can have someone in US send you some of these, huge savings over new:

https://batteryhookup.com/products/9-36v-bms-upgrade-to-500a-relay-fuse-kit

I bought a couple of those for playing with and I can say they are a pretty heavy duty piece of gear.

 

[robbob2112]

I bought a couple of those for playing with and I can say they are a pretty heavy duty piece of gear.

I have 8 of them without the fuse... $15... dunno what I would use the fuse for anyways.

 

[Brucey]

I have 8 of them without the fuse... $15... dunno what I would use the fuse for anyways.

To protect from a fault upstream of the battery? For $2.50 more seems like a decent value add.

 

[Daddy Tanuki]

I have 8 of them without the fuse... $15... dunno what I would use the fuse for anyways.

pretty sure it was you or @Brucey that recommended them to me several months back. I just bought several of them as I need some higher amperage relays that I can trust somewhat.

 

[k490]

Great the OP shares a lot of important information here regarding fire risk. Many thanks for that!
Here my system runs on 2x18 pcs EVE LF280K in wooden boxes.
Since I bought extra cells to create a 4p18S setup I planned to weld a steel rack with drawers in it.
You can keep the height low and store a lot of power into a lower height.
These drawers have hinges (extendable ball rollers) and can extend their own lenght outside the closet/rack.
Each set is ready for 250 kg's so enough for a 100 kg 18S string.
Very handy for maintenance too.

I will also include an aerosol extinguishing system (https://www.afxfiresolutions.com), two fireballs above he cabinet and place all in a fire resistant plated closet.

I use an XT4N ABB breaker , each pole pair one string, but ABB states they need two polepair for safe DC disconnect of up to 250V DC.
Since I use about 1/4th of the voltage, I asked them to check out if this is allowed.

now I want to combine a blade fuse (160 Amps - 50kA disconnect capacity) in each string of 18 cells, in series with a DC breaker.

Can anybody advise in what DC switch/contactor to by?
The american brand is nt sold here and Tyco EV200ANAAA vacuüm relays are the next option.

My BMS is the 123smartbms one, made in the netherlands.
They only work on root-level programming in the Victron cerbo, where I would like a CAN based BMS like the REC.
The bleeding with resistors doesn't appeal to me however, their pricing neither...

ABB breaker XT4N those are really expensive $1000-2000 or am I looking at the wrong ones. Is there somewhere you get them cheap? I saw a used one on eBay looked really old.

 

[doubledutch]

Not sure if you can have someone in US send you some of these, huge savings over new:

https://batteryhookup.com/products/9-36v-bms-upgrade-to-500a-relay-fuse-kit

Thanks for your reply, I ordered five new ones in Germany and payed €125 each for them.
Measuring the internal resistance with my battery resistance meter, only one had a contact resistance within specs!
The other ones had a resistance up to 24 mOhm . Am thinking the German company has been selling me used ones now...
Do they check these relays at battery hookup?

The ofher picture is my setup before repositioning the 3 victrons that hummed like idiots and leave me teeth grinding at the couch listening to their humm day in day out.
I placed them on a multilayer 22mm wood now and hope theae will keep silent now...

 

[Daddy Tanuki]

Thanks for your reply, I ordered five new ones in Germany and payed €125 each for them.
Measuring the internal resistance with my battery resistance meter, only one had a contact resistance within specs!
The other ones had a resistance up to 24 mOhm . Am thinking the German company has been selling me used ones now...
Do they check these relays at battery hookup?

The ofher picture is my setup before repositioning the 3 victrons that hummed like idiots and leave me teeth grinding at the couch listening to their humm day in day out.
I placed them on a multilayer 22mm wood now and hope theae will keep silent now...

pretty sure they are all pull offs, IE used.

 

[doubledutch]

pretty sure they are all pull offs, IE used.

That's the reason I'll only buy new ones at an official reseller. I won't compromise with the safety of our house.