BMS terminal clarification

columbiajack

10 mW
Joined
Mar 19, 2013
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I need to swap out a bms because of bad fets. The new Bms has terminals marked the same as the old. The B- "negative battery". P- "negative battery output" and the white sence terminal locations I understand. The ones on the end marked B+ B+ P+ P+ I don't know what goes there. The only wire which would be a guess is the negative charger wire. The only other I don't know what to do with the red+ and black- wires that were on either end of the sence wire connector on my old bms. The new bms only has 11 sence wires
 

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that schematic shows how to connect the sense wires. you do not have to bring the B+ lead over to the BMS using a large cable. instead you can use a small wire like the sense wires to connect B+ to the B+ spot on that BMS.

then connect the controller P+ directly to the battery at B+ with the large wire needed for the current.
 
dnmun said:
that schematic shows how to connect the sense wires. you do not have to bring the B+ lead over to the BMS using a large cable. instead you can use a small wire like the sense wires to connect B+ to the B+ spot on that BMS.

then connect the controller P+ directly to the battery at B+ with the large wire needed for the current.

Presently the B+ heavy out put is not connected to the bms. It comes out the pack to the main battery connection.

My confusion is where the Neg - charge wire is suppose to be connected on the new bms
And what do I do with the small red+ and black- that is currently on either end of my sence wire connector
Thank you for your input and patience. Jack
 
i explained how to wire it and there is a schematic in plain view. they use a red wire for the top and black for the bottom. if your BMS does not have a separate C- charging port then connect the charger negative to P- on the BMS. but only if there is no charging mosfet.
 
dnmun said:
i explained how to wire it and there is a schematic in plain view. they use a red wire for the top and black for the bottom. if your BMS does not have a separate C- charging port then connect the charger negative to P- on the BMS. but only if there is no charging mosfet.

Sorry I don't see a schematic in plain view. I don't understand red wire for top and black for wire bottom. What is top and what is bottom?
How would I know if there is no charging mosfet? Then the only thing is if you look close in the second pic there is a red and black wire on either side of the sence wire connector. What do I do with them? My new bms dosen't have them only 11 white wires Thanks again
 
B+ is positive from the cell pack
B- is the negative from the cell pack
P- is the BMS negative to your controller
P+ is the BMS positive to the controller
B0 is the cell pack negative
B1, B2, B3, etc is the positive sense wire from each cell.
C- is the charge socket negative.

Different BMSs are wired differently and have different numbers of pins on the multipin connector, so you might have to change the wiring a bit. Not all BBSs use B0. Often, they have no B+ either.

Here's a general schematic that might help you understand it:

 
That diagram is great! I have 2x10S 4P Tumich batts to set up for a bms.
otherDoc
 
d8veh said:
B+ is positive from the cell pack
B- is the negative from the cell pack
P- is the BMS negative to your controller
P+ is the BMS positive to the controller
B0 is the cell pack negative
B1, B2, B3, etc is the positive sense wire from each cell.
C- is the charge socket negative.

Different BMSs are wired differently and have different numbers of pins on the multipin connector, so you might have to change the wiring a bit. Not all BBSs use B0. Often, they have no B+ either.

Here's a general schematic that might help you understand it:


Thanks for the schematic. It would all fall into place if the new bms had a "C" charge terminal and if it showed what to do with the red + and black- wires on either side of the sence connector.
 
i already told you that if there is no C- spot on the BMS and it has no charging mosfet then you connect the charger negative to P- on the pcb. the red wire is the most positive sense wire and the black wire is the most negative sense wire. what else can i say?
 
dnmun said:
i already told you that if there is no C- spot on the BMS and it has no charging mosfet then you connect the charger negative to P- on the pcb. the red wire is the most positive sense wire and the black wire is the most negative sense wire. what else can i say?
Ok I understand to use the P- for the charge terminal
But what do I do with the red and black sence wires. The new bms only has 11 white wires. My old has 11 white and the red and black.
 
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