balance line missing

floydR

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Aug 23, 2017
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1,133
when i posted this last night the subject read "balance line not connected" should have read "balance line missing".
I have an older model of the Ant bms 8s-24s hooked up to a 24v BYD lifepo4 battery. The app shows all the cells voltages. 8 voltage sense lines and negative of the first cell (last cell by the BYD number system). The first line from the Bms connects to the negative of first cell.
What am I doing wrong? I will take a screen shot later today. Any ideas?

This is the bms https://www.aliexpress.com/item/32710469857.html

It may have been damaged it was sitting on a shelf for a long time,maybe 3 years since I received it.

All the balance lines have continuity. I believe they are hooked in the correct order. Will check later today.

Later floyd
 

Wolf

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Sep 25, 2018
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floydR,

After looking at the unit I believe pin 26 needs to be on the positive with pin 8 if you count the neg as pin 0.

Wolf

image_pjuwtz.jpg
 

floydR

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Aug 23, 2017
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1,133
The bms is connected as the diagram shows. I will replace the first wire that goes to the negative side of cell one but will wait till it cools off.
I took a photo of the bms app and realized I used the wrong subject line.

image_sgxurg.jpg

How can the balance line (negative line going to cell one) be missing? The bms reads the voltages of each cell (shown in the above photo)
Also the temperature seems wrong the temperature here right now is 102f 39c the temp of the bms is 31c.

Thank you room for all the helpful people here. :)

later Floyd
 

daromer

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Oct 8, 2016
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Its the same as the big negative lead.

Temperatures can be either due to missing Line or callibration is needed. They are cheap for a reason hehe
 

floydR

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Aug 23, 2017
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I have a 6ga lead from the b- to the negative of the first cell and the first balance lead is hooked to it. next 8 go to the positive sides of the cells. I probably need to start over, this weekend hard to do much work when it is over 100f 38c then I ill have a few hours I can work on it in the morning hours.

later floyd
 

floydR

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Aug 23, 2017
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1,133
The missing Temperatures because I hadn't gotten around to hooking them up. Now the temperatures sensors are hooked up and working.
image_ipcfmo.jpg

I will remove the 6 ga wire and solder a 10 ga wire in its place.

Better to experiment with Cheap stuff than mess up on expensive stuff. My soldering technique still needs work but is getting better.

later floyd
 
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