Basic Nissan Leaf 7 module Lithium setup with Generic Chinese BMS

[smbenson]

Thanks for the torque info. I 3d printed the spacers from thingiverse, but I think I will have to design a thicker one for that last cell. The gen 1 cells don't have sleeves in the holes or around the holes, just the aluminum sheetmetal case. When I assemble with 2 spacers on the last cell (because it's flipped) the rolled case edges meet. I would assume you would want to have some of the spacer showing to ensure compression.

Would it be better to just build 2 5S packs and put them in parallel so all the packs line up properly?

[Sergio]

You need to keep them as 5S2P in order to use a single BMS.

The modules should only touch on the perimeter near where the through bolts to through, the concave shape of the "sardine can" is the only thing that should compress the cell pouches inside.

A thicker 3d printed spacer should work fine although you will likely need the holes spaced a little further apart on busbars that connect to those modules.

[smbenson]

Removed

[smbenson]

I do need to make busbars - what is the width/thickness are the stock busbars for both main terminals and center leads?

[DaveTM]

My busbar's may have been "overkill" but the copper bar's were not all that expensive.

Go to https://www.mcmaster.com/catalog/127/4090/ and search for inventory number 8964k5.

These are 1/8" thick, 3/4" wide. I think I purchased in 2' lengths.

[WC53]

I am a bit slow on the uptake today.. so..

On the BMS, does it also has a B+ lead to help power the bms and allow the HV/LV relays to cut output ground to the relay K1 or is it powered from the balance leads?

Thanks

[Pat911]

It depends on the BMS but the cheaper ones mentioned in this thread are powered by the balance leads.

Cheers
Pat.

[WC53]

Originally Posted by Pat911

It depends on the BMS but the cheaper ones mentioned in this thread are powered by the balance leads.

Cheers
Pat.

Thank you, that is what I was left with after my pondering, I even broke down and read a manual!

[joepiccaso]

General Question, as I'm just now exploring the Lithium Battery packs. This tread has already helped a lot, but much more research is forthcoming. I'm quite handy, but not an electrical engineer. I need pictures and lists.

I have a '93 CC 6-Seater with 48V FLA system. Before my batteries die, I want to convert it to Lithium. My neighborhood in Atlanta is quite hilly. Can you, and is it wise to, add more battery packs to get more running time? I have plenty of room with the extra seat.

Good write-up and thread. Thank you!

[smbenson]

Sergio, I finally got my bms and am ordering the rest of the relays and misc parts. If my cart is only 36V with 10s4p leaf pack at 42v, how will that affect the Zenner diode, P1, other diodes for charging circuit K2 and K3? I am ordering a different 36V 120V relay for the charger as the I need only 36V. Easier way to ask: if only 36V do you need different resistors/diodes to get the voltage correct to trip the relays on the charging side?

Thanks for all the help.