Be careful

bgflyguy

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Jul 8, 2020
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Did this happen when you actually sat down in the chair? Any chance this was realted to that?
 

Kokireg

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Apr 30, 2022
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Yes there was my wife sitting on the seat but it has been like that for several months.

No, there was no insulating part between the cells but I don't think the blue plastic of the cells was worn out because of the friction because the cells were really well encircled and rest on anti-vibration foams.
 

brum

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Feb 8, 2022
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I see several issues in the way that these were mounted. You have plywood on top, but cell bottoms are visible. These should be secured to the floor and the only option to fix them with that enclosure will result in pressure over the cell terminals. The busbars are non-flexible and the cells were not even compressed. All of these are major flaws with your setup.

My bet is that this is the result of a short circuit and the flaws listed above have contributed to that.

Next time take care to protect them properly. The blue wrap should not be visible from the outside. Put spacers between them. There should be no pressure on the cell terminal. These do expand with the charge/discharge cycle and each cycle will put force on the busbar. A flexible busbar will reduce that stress. Since this is a mobile battery - put compression on the cells. This will likely reduce further the stress on the cell terminals.

And if I'm right about the LitoKala - go for cells from a verified reseller. LitoKala is not a cell brand, but a reseller. They don't produce their own cells. EVE, CALB, Winston - these are cell brands. Check the forum for more details.
 

Supervstech

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It is terrible when a battery fails in this manner. Doubly so when preventable installation shortfalls contributed to the meltdown.
Remember, the battery needs to be immobilized in the location, vibration is a nasty force on cells designed for stationary placement.
Always take plenty of pictures during and after the build completion. Haphazard conductor routing, inadequate insulation between conductive cells, poor fusing, weak bms lead routing and protection... all contribute to a failure, and any one flaw and poof...
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
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Oct 29, 2019
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Rural NE Ontario Canada
Clearly, it appears that several factors could have contributed either singly or collectively, and determining what exactly "did it" may never be realized. The space is very limited and is subject to issues.

The use of 320AH Cells, due to their size was somewhat over-optimistic given the location. Below are EVE cell measurements, I am unable to get consistent measurements for 320AH cells, which is peculiar & a flag.

1651445342937.png1651445478507.png1651445651262.png
 

DJSmiley

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Aug 13, 2020
Messages
585
Aliexpress and 320Ah cells... Well, first of all: There are no 320Ah cells. Also, I highly recommend avoiding Aliexpress for cells. Actually, any seller who sells cells with false specifications should be avoided. You cannot sell a 302Ah cell as a 310Ah 'since it usually is more like 310Ah'. The manufacturer does specify 302Ah for a reason...

Anyway: I think the way the cells are mounted is part of the issue. Strapping them with ductape is not a solid way to prevent movement/stress on the terminals.

Also, how are they mounted? Upright or in any other orientation? By the looks, the van looks like a Ducato/Jumper/Boxer/Relay/Promaster, and those have limited height below the seats. Maybe a short on the terminals, or downwards pressure from the seat?

And how was it stored? Was it charged below freezing temps? I know some Daly BMSses have no working low-temp protection, so in those cases it might have charged well below the temperature range.

And how was the protection on the bottom/sides? Can it by physical cell damage? By the looks, it doesn't look like there is much insulation on the cells except for the blue wrap.
 

Zil

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May 27, 2020
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1,833
You better listen to us this time. Cause we weren't there and we can guess.
 

KCBlues

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Feb 6, 2022
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22
Glad no one was hurt and there wasn't more damage done! That had to be nerve wracking...

How were the cells secured, and were they secured directly to the floor or to a mounting board and then the floor?

Was there ANY possibility for even the slightest movement?
 

Warpspeed

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Jun 11, 2021
Messages
339
Battery installed under the passenger seat.
That is suggestive.......

I have read that these cells should be mounted vertically (terminals up) or on edge.
Never flat side down.
The internal fluid is then able to cover the bottom half of all the internal pockets.
If mounted wide side down, half the internals are flooded and the half at the top run dry and that is aparantly a big no no.

I am a battery chemistry ignoramus, and have no idea what is actually going on, but I tend to read what the experts say and follow their advice.
I also have no idea if this is at all relevant to the failure, but its the only thing that comes to mind.
 
Last edited:

Warpspeed

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Jun 11, 2021
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Yes exactly Don, I tried to find that exact picture, but could not locate it.
 

Kokireg

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Apr 30, 2022
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36
no the cells were well posed in vertical

I am preparing my order (EVE 280k and JK b2a8s20p) and the design of the next one.
I will not make the same mistakes (cells in a solid box and closed for the new one)
 

Steve_S

Offgrid Cabineer, N.E. Ontario, Canada
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JK b2a8s20p
I strongly urge you to reconsider that one in favour of a B2A24S15P (150a) OR B2A24S20P (200a) which CAN do LFP 8S. Several people here have had "issues" with the B2A8S models. I found one of the Best Listing with the data, downloads etc is from Hankzor (Vendor)

TIPS: (See photo below)
- The BMS P- & B- silicone wires for the "15P model" are 7-AWG and both do fit into a 4-AWG Butt Connector.
- You can use 4-AWG Silicone wire to the Terminal Lugs to attach to cell + Batt Post.
- Hydraulic Crimper is Very Highly Recommended. (I use a YQK-8 Ton - works fine but tad fiddly, use a little cardboard to steady the dies straight.
- 1/2" Shrink Wrap for teh wires is perfect BTW, get lots.
-*- The BUTT connector is tough, The one linked here provides a mid-point deadstop (important), have a dimpled interior for added grab and provides 13MM of internal space on each side (enough for double crimp). Be VERY Careful on Butt Connector Specs they are NOT all the same !

Link to Butt Connectors from Digikey.

Link to Crimper:
NB: PITA to handle one person. Use a VICE to hold the unit, "not too hard eh", then it is MUCH easier to put the cable with "lug or" into the slot and hold it till you start to actually crimp the wires. Also NOTE, AWG is "slightly" bigger than the Metric but it is fine but leaves tiny "wings" once fully crimped, you will NEVER get the dies tight together because of that, it IS ok.

CRIMPER DIE CONVERSION (not easy to locate, jot it down)
Die Size mm/AWG/
4mm/12awg
6mm/10awg
8mm/9awg
10mm/8awg
(16mm/6awg/250mcm)
(25mm/4awg/300mcm)
(35mm,2awg/350mcm)
(50mm,1/0awg/500mcm)
(70mm,2/0awg/600mcm)

8S-connections.JPG
The BMS Extensions: I made mine this long because of how I built my battery boxes.
BTW, I ended up with RED jacketed as they were out of stock on Blue. like the other wires, ultra-fine stranded wire in thick silicone jacket.
BMS Wiring-extensions.jpg
 

Kokireg

New Member
Joined
Apr 30, 2022
Messages
36
thx à lot for your answer
but I go up in 4s for a battery of 12v (10- 14.6).
I know that a priori we can mount them with a booster after off grid garage
 
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