Shunt snapped and caused a fire🔥

[Cheap 4-life]

I agree with your points 1-4 but not with 5. The EV packs these cells are designed to go into use rigid compression with no expansion mechanism. They won't vent just from being held regular fully charged expansion pressure. Preventing that regular expansion seems to be precisely the intention of EV pack compression.

I could be very wrong
I’d think preventing any expansion in a completely rigid fixture would cause venting and or fire IF the cell experienced more expansion than what would occur from a normal full charge. Also if the cell was discharged with to many amps or simply abused then more than normal expansion could occur. I’d assume EV pack manufacturers aren’t as concerned about preventing fire from a rare instance that most likely won’t happen due to utilization of a bms. They are probably more concerned about preventing cell deformation so the packs/cells last for more years/cycles. In a high demand (but within cell spec) application (like in an EV) preventing constant expansion and contraction with a rigid fixture would prevent excess cell deformation.

 

[Brett V]

well some thought that the DALY's might have been a concern. hence my asking. I think you just got a bad one honestly as other than not reading low current draws and low current charging (throws off the SOC) Mine have all worked including low/high temp shutdown. I have my SCC set to never overcharge so the BMS is a backup in that regards same for genset charging that is needed once or twice a winter season, so I cannot vouch for that as the SCC and the charger in the Magnum inverter have covered those issues to date.

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.

 

[k490]

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.

 

[Brett V]

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.

I’ve done two battery builds in aluminum truck toolboxes. One wall mounted and one on wheels.

New Battery In A Toolbox

Finally finished my upgrade build. Had one set of EVE 230's mounted in a small wall mounted toolbox. Was going to duplicate that with a second set of the same batteries but decided to do something different. I now have two batteries in a 48" toolbox and put a set of wheels on the bottom so...

diysolarforum.com

 

[k490]

I’ve done two battery builds in aluminum truck toolboxes. One wall mounted and one on wheels.

New Battery In A Toolbox

Finally finished my upgrade build. Had one set of EVE 230's mounted in a small wall mounted toolbox. Was going to duplicate that with a second set of the same batteries but decided to do something different. I now have two batteries in a 48" toolbox and put a set of wheels on the bottom so...

diysolarforum.com

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.

 

[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.

SOK 12-Slot Outdoor Insulated Battery Rack | Current Connected

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