Right…
but if you have a smart “LiIon” BMS you can set the cell max voltage to a value appropriate for LiFePo…
Right? I mean, why not?
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the BMS police will show up
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if its a programmable BMS then sure, as long as there’s enough play in the setting’s ranges. It’s all about min and max voltages and cutoffs.
This is real. Every time i get balance leads out of order they show up and beat me with their night sticks.
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The BMS police are even more frisky in NYC.
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Don’t skip any wire and don’t watch videos if it’s not about your specific BMS. BMS can be very different to connect and the diagram of the manufacture is most important not any random diagram you can find, be safe bro!
Your BMS is weird but other guys use it so it should be fine. What confuses you (and me) is the fact that the print on the PCB of the balance leads doesn’t match. So you have to count it yourself and forget the print.
Let’s talk about your case with 2x 6s lipos
Very important is that lipo1 has the main negative battery pack lead (and cells 1-6) and lipo 2 the main positive battery pack lead (and cells 7-12). lipo 1 main positive is connected to main negative of lipo 2.
I would not cut the balance wires of the lipos. I use 6s extension wires (or solder male jst-xh connectors). This way it’s safer and you can always balance charge if your charger or BMS fails. Just pay attention that you don’t use the B1- of the second lipo.
So the black balance wire of the BMS (B0-) connects to the black (or the first) balance wire on lipo 1, the first white wire (B1+) after the black one (of BMS) connects to the second wire of lipo 1 and so on until wire 7 of the BMS (red balance wire on lipo 1) which is the positive of cell 6.
On lipo 2 you skip the first balance wire (cell 1 negative) and connect only the remaining 6 positive wires (cell 7-12) of the BMS to lipo 2, the red balance wire of the BMS is also the last (red) of lipo 2.
As mentioned earlier forget the print on the PCB, the first white wire after the black is cell1+ and the last red one cell12+.
Always connect B- of the BMS to battery negative before plugging in the balance wires to the BMS.
I hope you are not more confused than before 
.
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You are my Savior and a Jump Master! (Thank all of you for real though!)
It’s all hooked up and Im connected via app!
Shows all 12 cells and they are all looking good.
Plugged in the 12s charger and Bam! We have charging!
Now to read up on how to configure the rest of the settings before making
a place for this in my Box. I know Im pretty much just matching specs from the battery
to the BMS but thats my final step!
Im soOooooooOOooo Hyped!
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Glad to hear it works 
I don’t know this BMS but probably you can keep the stock settings except for over-discharge.
Li-ion and lipo are quite similar except 2 things. First is the end of discharge. You should not discharge a lipo below 3.2V per cell, better is 3.5V. Personally I discharge lipos to 3.2V because I need the range but they never last longer than 1 year.
Many li-ion cells can be discharged until 2.5V or 2.8V. If you go below 3V per cell with a lipo the chance of damage is big. So a over-discharge setting of 3V or 3.2V per cell bla bla bla I’m a moron because you bypass the BMS for charge so this setting is useless in this case.
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xiaoxiang BMS CONFIG
DESIGNED CAPACITY
- What is the range of the pack in mAh
CYCLE CAPACITY
- How long do you ride/cycle before you charge
FULL CHARGE VOLTAGE
- Your single cell max charge. Defaults 4150 or 4.15V per cell
END OF DISCHARGE VOLTAGE (Most likely bypassed)
-
Your single cell voltage max low. Defaults 3000 or 3.00V per cell.
-
when the BMS cuts of your power due to low battery IE End of discharge voltage.
SELF-DISCHARGE RATE
- How fast the pack will discharge while not in use.
- may want to set to 0 for lipo’s.
80% 60% 40% 20% Capacity Voltage
- I assume this is for warnings to be shown when hitting these marks.
START VOLTAGE
- When balancing should on a given cell. default is 4000mV or 4.0v
DELTA BALANCE
- How finely you want your balancing to be in mV.
- Default is 30mV or .03V.
- This means it will attempt to balance each cell within 3/10th or a V
BALANCE ENABLED
- self explanatory
BALANCE ONLY WHEN CHARGING
- self explanatory
- may want to leave set to only charge so your battery is not working more than it should when not in use.
CELL OVER VOLTAGE
- [Trigger] When do you want the BMS to stop the flow of current based on a cell.
- [Release] When do you want the BMS to allow current to flow again and remove warning.
- Default is 4250mV or 4.25V per cell, which I believe to be too high.
- I will set mine at 4150 or 4.15V and release to 4050mV or 4.05V
CELL UNDER VOLTAGE
- [Trigger] When do you want the BMS to stop the flow of current based on a cell.
- [Release] When do you want the BMS to allow current to flow again and remove warning.
BATTERY OVER VOLTAGE
-
This is your batteries max charge of the entire pack.
-
default is 51000 or 51.0V
-
[Trigger] When do you want the BMS to stop the flow of current.
-
[Release] When do you want the BMS to allow current to flow again and remove warning.
BATTERY UNDER VOLTAGE
(if discharge is bypassed this ca be ignored but can throw flags/warnings if not set.)
- This is your batteries max low of the entire pack.
- default is 32400 or 32.4V
- [Trigger] When do you want the BMS to stop the flow of current.
- [Release] When do you want the BMS to allow current to flow again and remove warning.
CHARGE OVER CURRENT
- BMS will cut power from charger’s that exceed these set parameters .
- Example: If you plugged in a to powerful charger this can prevent harm by cutting the current.
DISCHARGE OVER CURRENT (ignore if BMS is bypassed)
- BMS will cut power to source of what ever is drawing to much current based on these settings.
CHARGE OVER TEMP
- Prevents charging when too hot.
CHARGING UNDER TEMP
- Prevents charging when too cold.
DISCHARGE OVER TEMP
- prevents power to board if too hot.
DISCHARGE UNDER TEMP
- prevents power to board if too cold.
.
.
.
So I think I have Documented the config pretty well.
Let me know if you see any issues with this explanation or ways I can edit to make more clear.
Side note: this is not how I have my config setup but this is my understanding of the config itself.
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do you feel these are worth the small price jump from a “dumb” BMS?
I wish I had nothing but them haha.
If the above is correct and I think it is.
I would say yes, these are pretty neat to say the least.
If you planned to use all the functions they are even more worth it to you.
I will use this for learning more of whats going on inside my build.
I think with a Lipo this might be more safe since you can check your cells on the fly.
I suppose same for any battery but lipo’s seem more dangerous from what I hear.
I like the fact I can set a cut off for charge to keep my battery at 95%.
This way I can bomb my hill without worry and keep my battery longer by not fully charging it.
I like the overcurrent charge settings that prevent
you from plugging in a 20A+ charger to the pack.
The BMS just stops your charge current. Which is nice for me if I have someone plugin a board.
I have random chargers all over and nice to know know one can really mess it up now.
Im also digging the way you can set the low volts. So if you don’t want to drop your battery
to the bottom you don’t have to. I myself will only see a warning in the app I believe because of
bypassing discharge but it’s nice to know I can setup that even if just for a warning.
Personally wish I would have just ordered these and not the other two 12sBMS’s I have in route.
There is just a lot to like about these SMART-BMS’s.
If you have a METR then you will love one of these.
An if you don’t have a METR then go get one of them first.
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ah yes I need to try connecting it to METR for sure!
That feature needs its own damn thread!
Ive yet to do the METR and S-BMS but I will soon.
I just now got all my settings in order I believe.
Should be a simple press of the pair button in the METR app though.
Settings/Battery/Pair with BMS
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I installed my Xiaoxiang BMS and per the video my volt reader checks out with each progressing by 4 Volts up to 49.4V total on the last negative (black wire). But the Xiaoxiang App is saying my first two cells are near 0 and 2 Volts, for a total of 43V. I have no clue how to set up the App. I “read data” in Configuration and most of the values match other screen shots I’ve seen on this website. Not sure why the App isn’t recognizing the first two cells properly?
Is your website down? I get an error message for esk8life.com
Thanks.
Do you have the B- solder pad on the side of the BMS connected to the B- of the pack?
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No. I just have the balanced wires connected.
Is that a three port connection with positive / negative from the battery and the B- from the BMS ?
AKA: Black wire from batt to “B-” on bms!
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There is the Xt90 end that goes from Battery to ESC straight line.
Then from that straight line there is a Neg to the BMS and Neg out to charge.
The positive from charge goes back into the straight line.
So the Negative of charge is all that is running through the BMS.
This would be bypassing discharge or a charge only BMS setup. 
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Got an similar BMS. Got two 5s Lipos. Connected them in series so that gives me 10s. Currently working on the balance wires. Drew up a diagram and was wondering if this is right? So I know for battery 1. I connect up to N4, skipping N5. Battery 2, connect the rest. The end the black wire
(Diagram i drew below, the fuse will switch with the negative wire. Connecting to the C-. Going to the negative wire, then going to the charge port)
