32x EVE LF280K pack configuration - need second/third opinion

zolee

Solar Enthusiast
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Jan 31, 2022
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Hello,

I'm soon creating a 16S2P battery from 32 EVE 280Ah cells. I need to hear your opinions (and I'll try to not ignore them :) ).
Here is my proposed schematics:
Screenshot_20220404_205344.png

The cells will live inside a welded frame, with own tray for each 16S, with silicone insulation between cells and something else electrically rated for floor and sides (not determined yet).
BMS is 2x Seplos 150A 16S.

I want each bank to be easily disconnected so that's why the Anderson connectors, the same is for the inverter.
Each bank has it's own fuse (Bussmann 250LMT), connected to busbar with 50 mm2 / AWG 1 short cable, and the busbar has a Bussmann 315LMT for the inverter connection. Inverter cable is 70 mm2 / AWG 2/0, cca 1.5m.
The busbar specs are not yet know, but it will be a beefy piece of copper bar from workshop leftovers (we do LV distribution cabinets).

All the cable runs and cells will be properly insulated from the welded frame.
The cell trays will be spring loaded to 300kgf.

What I am missing here?

Edit: Ignore the F3 on negative, it should go to positive. Drawing error.

Thanks
 
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zolee

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I like it. Some like a disconnect switch but I would go without.
Proper disconnect switches are very expensive. Instead I have Anderson plugs with pull handle, strategically placed for fast disconnect.
In case of emergency the fuse should do it's job.
 

time2roll

Photon Sorcerer
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Mar 20, 2021
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Best to reduce load before disconnect. This would go for a switch or the Anderson. BMS may have this function on demand.
 

zolee

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Best to reduce load before disconnect. This would go for a switch or the Anderson. BMS may have this function on demand.
Yes, that's absolutely correct. I was talking about emergency disconnect in the situation when a person is present and damage to connector is acceptable. I believe it works better than the cheap disconnect switches.
When unattended, the only protection is the fuse.
In normal maintenance mode the battery must be off before disconnecting.
 

Samcat

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May 31, 2022
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If you want less bus bars ( less resistance more efficiency) i would go with two parallel 16S battery banks. It will require one more BMS . This what i have learned working with EV battery packs. And slowly moving away from P and S in one battery setup. If you are going to scratch my advice. Invest on flexible cooper bus bars and stay with your design. Good luck and looking to see some pictures of your almighty setup.
 

zolee

Solar Enthusiast
Joined
Jan 31, 2022
Messages
32
If you want less bus bars ( less resistance more efficiency) i would go with two parallel 16S battery banks. It will require one more BMS . This what i have learned working with EV battery packs. And slowly moving away from P and S in one battery setup. If you are going to scratch my advice. Invest on flexible cooper bus bars and stay with your design. Good luck and looking to see some pictures of your almighty setup.
Thanks,
If you check the drawing it shows two BMS like you said. I just didn't bother to draw the second pack. I'm not paralleling individual cells.

The busbar between packs and inverter (J3) will be a heavy copper bar, probably something in the range of 60x20x250mm or bigger, resistance is not an issue. I can make it as big as I wish or can fit as I have access to leftovers from the company workshop (we are making electrical cabinets).
 
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