What is the wire for?
- Increase the conductivity to support higher current
- Connect all cells in the p-group for balancing
- To keep the nickel from not bending tight enough to snap
Oh I understand now. I am guessing you didn’t notice that the connection was there in between. Because it is easy to cut it off with shears…
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Ya, I have since cut the connection. It’s working fine now. Except the 4 cells that are now garbage.
I would bend the pack back out and solder the wire at the bend so when you fold it back it will prevent the nickel from creasing. I have never seen it done like that. I just used copper braid and that folds nicely.
The solder prevents the nickel from folding. Already tried doing it that way 
Oh damn I guess it would. Idk then.
Its faulty?? Bugger. I bought 2 so will try the other.
Did you contact LLT support or go through Ali Express? (Assuming you bought through aluexpress?)
I think it is faulty. I have checked in the pc tool to and same reaction from the bms.
I only discovered it today when I was building a pack. I have messaged both, will see what they are going to say.
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I would appreciate any updates 
Thanks for the heads up 
You numbered the cells the wrong way around pgroup 1 starts at the - side for most BMS.
Seems like the LiFePO4 packs I built can’t supply the power I need for my ESC / motor setup. The pack can supply 150A, but the motors can draw up to 160A.
Unfortunately this causes some dangerous stuttering under high load, which is pulling away from a stop, accelerating hard, going uphill and braking hard.
Pisses me off because 1) I didn’t think it’d be such a problem, 2) due to all the effort I put in building these, and 3) now I still need to fiddle with LiPo charging.
I’m also not carrying another 4.6kg P group around, which would fix the current issue. So if I wanted to go LiFePO4 it’d need to be with the Headway 38120HP’s.
Confirmed the above by running the board with my graphene LiPo’s instead and having none of the same issues. LiPo’s at 16.3V per pack and LiFePO’s at 16.6V per pack.
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@Darkie02 my bms is wired correctly. The balance connector is upside down, hence the reversed numbers. I took this bms from a working pack, I labeled every wire and position before removing it from the old pack.
That’s either a faulty bms or pgroup. Since it’s only happening on 1, I’d turn towards a faulty bms.
This pic is when I had a cold solder between 2 pgroups.
Verify that touching any wire doesnt change anything. (IE: touching wires badly soldered could disconnect and would show up as dead in the app)
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Does anyone have a link to nickel strips(or roll) that is 2 or 3 cells wide? Like 30mm-50mm wide?
Interesting, I’m pretty sure my pack soldering is ok, I will open it up if needed but would not be happy if I split it and it was a faulty bms!
Just looking at the S charge graphs, looks l9ke it was only S pack 1 that exhibited the red bar.
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Dont think a dead pgroup would react this way. Do you have another pack you could connect the bms to?
I do have another but wasnt planning on chopping into it as it’s in my other board. But it sure would tell. Good shout.
Thinking about it, I have another new llt bms too, maybe I’ll try that first…
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I’m interested in something. Let’s say you have 3 same boards with same setup and everything, just with different batteries.
- 10S10P with let’s say Samsung 30Q cells.
- 5S20P same cells
- 20S5P same cells
Each battery has 6300W of power. In theory the higher voltage should be more efficient. With 1. you get 50km/h of top speed and 100km of range. What top speed and range will you get with 2. and 3.?
I might be wrong, but they will all have the same range. 2 will be half as fast while 3 will be double as fast.
Realistically the difference is probably not as big in terms of speed.
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