Damn, that was a brand new BMS too! Guess I’ll replace it with a charge only BMS.
Thanks bro for guiding me out, ur the best! 
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Did you solder the B- before plugging in the balance connector?
Many BMSs don’t like it if you do it the other way around and commit suicide in protest.
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Don’t remember if I soldered B- b4 plugging in the balance connector, now I know. Thanks for the heads up.
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Iirc there are two pegs in one of the jst on the unity that have to be bridged to allow for the use of another power switch.
I may be off topic but I only scimmed through that convo.
I read somewhere that the two white wires on the Unity switch needed to be shorted to allow the use of another power switch.
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I love it when I’m right lol.
Also, unless you have the exact jst to fit the unity jst (I believe the unity jst is different from former esc), solder the jumper on. Less worry of it coming loose. You dont want it ever to come loose while riding lol.
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Go back to pineapples Jack. 
Read the whole thing, his BMS is not outputting the full battery voltage. It has nothing to do with the Unity.
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Still riding lol.
Hey I did note that I scimmed through lol.
Going back to the ride… 
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Ride safe.
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I ll take one, just had an incident a friend of mine. wanted to check if I soldered the positive and the negative to the right charge port pin with ohm meter beeper, of course he hit the pin and the wall in charge port
Send me a PM
EDIT: realized I can remove the nickel strip on the positive terminal since I’m using a PCB… my bad.
Hi everyone,
I’ve decided to build my own 12s4p (this is for my board) and 12s5p (for a friend) that has safety and high quality in mind.
I’d love to receive feedback from the larger community about the design I’ve come up with and whether any holes exist, or where I could potentially improve further.
Questions (some of which may have been beaten to death):
-
Thoughts on 9.5mm flat tinned copper braid vs. 2.5mm (10AWG) wire for series connectivity?
-
Dead horse debate: glue or silicone? I’m thinking Permatex 83913 RTV Clear Silicone for the P groups. Thoughts?
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Fish paper on the negative terminal?
-
Recommended cell holders and charger?
Also… balance wiring confuses the living shit out of me (for now). How do we go about ordering the wires with the correct pack?
Thank you!
- 2x 12AWG is better than both of your options. One between cell 1-2 and the second between 3-4.
- neutral cure silicon all the way
- no need for fishpaper on the negative terminal, but between the parallel packs if they not placed separate
- what you mean with cell holders? If you silicone them together no need for cell holder.
Charger depends on with which current you want to charge. 4A seem to be a good middle way and works with most charge ports without getting hot. Just search on AliExpress for 12s Charger you will find a big selection. Make sure it’s for LiIon an lipo, not lifepo4.
Additional question: the balance wires with plug usually come with the bms.
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Thanks!
For 4: I was looking for something to hold the cells in place while I place the silicone in between them. Sorry… totally not clear.
As for the balance wires. I should have been more clear on that front as well. I was curious to know in which order are they placed on each of the P groups. How do I know which is P1 vs. P5.
Someone correct me if I am wrong, but P groups should be bonded in parallel, meaning they have the same pos and negative.
To me this means that all P groups per series cell share a single balance wire.
In other words in a 6P pack, those 6 cells would have 1 balance wire
I have always wondered how long these 6P packs take to charge, especially considering that they have small 22 awg wires usually - do all 4 or 5A go through that?
Hi everyone! I was wondering what would be a good way to test a cell for experimenting with cell level fusing. Just looking for a way to pull a constant 20A or so to see how hot the fuse bit gets under load.
i needed this…thx
The balance wire doesn’t deliver the charging current, that goes through the main leads and the entire pack.
The balance wire only sees around 100mA, wich is typical balancing current. That’s why you can use small gauge wires for balance connections.
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Ah that makes sense. Just drains off the top when necessary.
Check all balance lead voltages again? Could have lost continuity on one or more when tightening the enclosure?
Overall, you can set up the BMS to be “always on” or the unity to be “always on”. Then use the other component to do the on-off. If you lock bms on, you get the unity’s push-to-start. But then you have more things that are “on” when the board is off.