Wiring BMS to modular pack - need opinions

Joined
May 25, 2021
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12
Location
Arizona
I am humbly asking for assistance, opinions and guidance in wiring a new BMS to the pack I am building. Each P-cell has a 9.5mm braid that runs underneath the 3d printed holder pictured below. Each cell has positive and negative 12AWG wire that will be soldered to the braid and then terminated with 4mm bullet connector. I haven't completed (heat shrink/strain relief) the individual 6p cells as I would like some ideas as to where to place the BMS leads.

individual_1.jpg

From what I understand, I need to place the leads on the positive side of the P-cells. In my case, do you think it would be best to solder the leads to the wire at the bullet connector or closer the braid?

individul_p_group.PNG
Disregard the negative side connections, as I made a mistake on that.

I am going to use a Daly BMS pictured below:
daly_BMS.jpg

I am not sure if I should use XT60 or 4mm bullets for connecting the pack to the BMS and charger. Opinions on that?

Here is an overall diagram I am drawing up to guide the final push for construction:
overall.PNG

I will finalize and submit for comment before I actually power this thing up. My charger setup is completely configurable from 5v to 60v and 0.1ma to 6amp.
 
I'm not the most knowledgeable on batteries, but in my opinion looks great so far
,think BMS wire work fine soldered to bullet connector on positive wire, avoids solder heat on the positive not as volatile as the negative but non the less , maybe slightly easier disconnect if need be to, in keeping with your modular design. Also avoids wiring on top and bottom of 3d printed portion so might make the pack slimmer in that dimension,
lots saying bullets are good especially high current areas like motor phase connections,
i like XT connectors they are available in anti spark versions so great for battery connections, but probably be good idea for your charger connection as well as most chargers spark when you connect them due to it's capacitors discharging even when not plugged into the wall, not really a problem but be nice if didn't, :bolt: anti spark XT might fix this,
but not to sure if your charging method will react to small resistor in the XT if anybody knows answer I'd like to know :)
With regards to your other post about your pack I was using same 12 awg wire for main battery wires other day was surprisingly hard to solder , my soldering iron not get hot enough , and strands very fine not like copper, expect you know what mean :wink:
think this and braid more geared toward crimp connectors , I'm not big fan of crimp connectors unless big blob solder as well, but might as well just solder then ,keep joint size smaller yours look good ,well bonded and don't think you'll ever be able break it, from the times I've ripped wires of PCB s the solder joints have been unexpectedly strong, good you got BT BMS as you can see what your pack is putting out peak then dial BMS and controller back a bit for longer life of components, did it come with app as there is a post on here about someone having bit of prob downloading but think they have solution too :mrgreen:
 
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