# Need BMS For LG Chem



## frodus (Apr 12, 2008)

Zeva is pretty flexible. I don't think you can use Orion for that, since you'd need 1 central BMS per parallel group, and you have 4. You still need 11/12 modules from Zeva, but they're far cheaper and it supports parallel groups. 

I'd go for distributed for these, since you're paralleling modules and you should not connect the cell taps to each other (current will flow across during charge/discharge).

I looked into buying these and the Zeva checked all of the boxes, they're easy to deal with and the modules themselves are fairly cheap and you only need one master + 12 modules + LCD. I've used one before on a 24s Go Kart and it works great.


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## john61ct (Feb 25, 2017)

Don't know their layout, but be aware many designs use each input to monitor each lowest-level parallel group of cells, considering monitoring each cell individually to be overkill.


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## daltonguitar (Apr 18, 2018)

Thank you for the comments. So if I have the choice to monitor each cell individually or each parallel group of 4 cells with the same voltage I would rather do the later just for money sake. Once I have enough funds I can change to an individual level.

In the meantime, I made a schematic of how I believe the BMS and batteries need to be wired. It is attached to this post. Let me know your thoughts or if I messed up anything.
Thanks for all the help


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## frodus (Apr 12, 2008)

No, you need one set of 3 BMS modules for each parallel group. You cannot parallel the packs at the cell level, not without significant work and large gauge wires connecting all cells together in paralle. These LG modules are difficult and cells are not meant to be put in parallel. 

You will need to monitor and balance as if you have 4 separate packs, each pack requiring 3 BMS slave boards. Total 1 master and 12 slave boards.


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## GregShay (Aug 20, 2016)

frodus said:


> No, you need one set of 3 BMS modules for each parallel group. You cannot parallel the packs at the cell level, not without significant work and large gauge wires connecting all cells together in paralle. These LG modules are difficult and cells are not meant to be put in parallel.
> 
> You will need to monitor and balance as if you have 4 separate packs, each pack requiring 3 BMS slave boards. Total 1 master and 12 slave boards.


@frodus
How do you mean you cannot parallel the LG Chem modules at the cell level? Inside the Nissan Leaf metal cans, are LG Chem modules paralleled: 2s2p. 

The one trick is to make sure cells to be connected in parallel are at the same charge voltage level before you connect them together, to avoid high currents as they equalize. 
Greg


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## daltonguitar (Apr 18, 2018)

Thanks for all the input guys. So I have decided to go with the ZEVA BMS that frodus recommended I go with.

For anyone else who is working with these modules heres something that might be of use. Apparently EV West has PCB boards that allow for paralleling with a fuse on the LG modules, and they sell them for $39 each. You could also parallel them in the harness if you wanted but I thought I'd put that out there in case you're in the market.

When it came to cost, monitoring every cell with ZEVA turned out to be around the same price as parallel monitoring with a Dilithium BMS with the PCB boards. I also ordered the CAN hall sensor interface, 1200A max and the EVMS Monitor V3. Figured I might as well want to see what the hell everythings doing in the system in case any problems emerge. 


Appreciate all the comments


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## NikMish (Aug 29, 2019)

Subscribed


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## baxy (Dec 24, 2017)

daltonguitar said:


> For anyone else who is working with these modules heres something that might be of use. Apparently EV West has PCB boards that allow for paralleling with a fuse on the LG modules, and they sell them for $39 each. You could also parallel them in the harness if you wanted but I thought I'd put that out there in case you're in the market.


link?

Sent from my SM-G975F using Tapatalk


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## daltonguitar (Apr 18, 2018)

They're not on the EV West website yet but if you email any of them or call them they'll tell you about it. Went in and saw them in person they're really cool and just attach to the standard LG Wiring harness. Also, considering how cheap they are I am going to try them on my build just to see how it will work. Ill keep you updated.


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## leman2112 (Dec 2, 2018)

Got the same pack! Thanks for making this thread. Thunderstruck ev sells the OEM bms connection s for these cells. In case anyone was interested.


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