Greetings. Assembling a 12s9p battery with the help of a local builder. Upon starting to wire the Bms he realized that it seems LLT shipped us a 13s or 14s unit when I ordered a 12s. The one we have has 13 white wire leads and the 12s is supposed to have 11 white wires. Are we screwed? Or is there a way to make this work? I’m come across a couple discussions saying it can be made to work but no specifics on how to do it. Any thoughts or suggestions?
I think there is a way to make it work, I think it involves shorting across two pins but I can’t remember. Someone on the forum mentioned it before, have you tried searching here yet?
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I have yes, but havent come across something concrete
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Yeah I don’t remember but I know there is a way. Have you tried contacting LLT?
Yeah we’ve emailed twice but no response yet
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12s bms should have 13 balance wires, not 11. First black wire, 11 white and 13th red wire.
Edit: so you have 13 or 14 white wires + red + black? I didn’t understand it quite right.
Anyways, you can program 15s llt bms to work as 12s. @Acido can help here
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His has 13 white. One red and one black. Sounds like a 14s version.
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Balance wires should be the number of cells plus one so your 12s bms should have 13 cables
I found this image somewhere in some LLT documentation. The right side shows 12s wiring. I used it to convert my 10S smart BMS into a 12S BMS.
Make sure to solder the pads inside the BMS together that don’t line up with individual balance lines. There should be 15 pads and 2 sets that are soldered together for 13 wires. I might be able to try to find pics of mine.
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which pads ?
isn’t it supposed to be a software setting ?
I ordered a 12s BMS but after a change in plans, i’ll go for a 10s bat, i’d love not to have to order another one
You can make it work, but you need to know the correct pins to short and you need to change the parameters in the app. Best get in touch with them.
They are usually pretty helpful, but their website was definitely down for a few days at least last week, maybe shoot them another mail, as it appears to be back up now.
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“if you need to change it for 10S application ,please bridge the BC3~BC4 , BC7~8~9 , BC12~13~14 ,and arrange the wire correctly . then connect it to the 10S battery . after connection , you should input correct protection parameters”
here it is, fast answer, good service
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Just make sure it is right, you would be directly shorting out the cells if its done wrong. The wire would probably melt… Make sure there isn’t more than 1 wire going to the bridged pads
yeah sure,
bridging the pads is a curious way of doing it, i wonder why it doesn’t just work as a lipo blance charger, where you just let unpopulated the cell pads you don’t need
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Yeah its weird. But it works, can confirm. Have changed a couple of 12s to 10s no dramas.
Also, if you do get it wrong… its pretty awesome seeing an entire balance lead vaporise in front of your eyes 
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I’m sure it is, once my bms is perfectly setted up, i’ll go watch videos on youtube 
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Those things never timeouts ?
Won’t it drain the battery instead of protecting it, on storage ?
What u talking bout? The bluetooth module? The bluetooth module will remain on as long as the app is open on your phone. As soon as you close the app, the bluetooth module shuts down.
I assume that if the battery ever gets dangerously low, that the bluetooth module would not turn on at all… but that’s an assumption, I don’t know for sure.