BMS wiring seems a bit tricky

[ebike11]

Hi guys

Im hoping to get some help for wiring my first diy bms to my LG pouch cells.
I have 18 cells of long LG pouch type like this..but not these exact ones. However the dimensions are the same.

https://m.dhgate.com/product/ev-battery-high-capacity-3-6v-60ah-prismatic/472469652.html#redirect_detail=PC2WAP

Because of their length, I had to mount them separately in different areas of the bike (inside the frame and on the rear rack)
I can not physically connected all 18cells together as it wont fit my application, so splitting the cells up is my only option.

The 2 packs in the center of the photo below were able to be connected with short wiring and those 10 cells are in the same bag.

Also since I wasnt using a bms, i just connected separate JST plugs for each pack to monitor the cells
Since each pack has its own main positive and negative connector, i had to make 3 way connectors to connect packs to each other to increase the voltage.

Ive recently purchased a bms so Id like to wire it up.
Since I have 4 JST plugs already connected, could I just run the bms balance JST wires to those? If its possible then i need to wire them in the correct order correct? Id have to be careful.

I have the main wiring from the bms wired up..just need to focus on the balance wires.

Any tips will be greatly appreciated! Thanks!!

 

[ebike11]

Would anyone have a tip? Thanks

 

[Jonno]

Looking at your picture (as the link doesn't work)


Neg of the 3 cell pack is your 1st wire on the bms followed by your 3 pos wires on the same jst.
Next are the 5 pos wires on the jst to the left (Skip the Neg)
Again next are the 5 pos wires on the jst to the left (Skip the Neg)
Again next are the 5 pos wires on the jst to the left (Skip the Neg)

You can then test this with a volt meter from your original Jst neg to each of the pos wires and the volts will increase by 1 cell per each wire.

You can always test this before you connect the bms

Jonne

 

[ebike11]

Looking at your picture (as the link doesn't work)


Neg of the 3 cell pack is your 1st wire on the bms followed by your 3 pos wires on the same jst.
Next are the 5 pos wires on the jst to the left (Skip the Neg)
Again next are the 5 pos wires on the jst to the left (Skip the Neg)
Again next are the 5 pos wires on the jst to the left (Skip the Neg)

You can then test this with a volt meter from your original Jst neg to each of the pos wires and the volts will increase by 1 cell per each wire.

You can always test this before you connect the bms

Jonne

Thanks for your reply!
I have fixed the link above
I will follow your instructions..its my first time wiring a bms

 

[ebike11]

Looking at your picture (as the link doesn't work)


Neg of the 3 cell pack is your 1st wire on the bms followed by your 3 pos wires on the same jst.
Next are the 5 pos wires on the jst to the left (Skip the Neg)
Again next are the 5 pos wires on the jst to the left (Skip the Neg)
Again next are the 5 pos wires on the jst to the left (Skip the Neg)

You can then test this with a volt meter from your original Jst neg to each of the pos wires and the volts will increase by 1 cell per each wire.

You can always test this before you connect the bms

Jonne

Hi..dont you have to make a Y-split when connecting different packs, from the last cell to the first cell of the other pack?

 

[Jonno]

If you think about it your 4 large packs are just 1 big pack in series, they just have a pos/neg wire separating each pack. Therefor you you want the neg of the bms on the neg of the neg of the 1st cell on the series neg end (the 3 cell jst neg) then 1,2,3 then 1,2,3,4,5 from the pack to the left and so on.
Your bms will not work unless all 4 packs are connect in series.

I can draw it up if you are still confused :

Jonno