# BMS noob question

**URL:** https://foil.zone/t/bms-noob-question/7157
**Category:** Electronics (ESC, remote, batteries)
**Created:** [March 19, 2020, 1:55pm UTC](https://foil.zone/t/bms-noob-question/7157 "2020-03-19T13:55:56Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![Nickwad](https://foil.zone/user_avatar/foil.zone/nickwad/32/11424_2.png) [@Nickwad](https://foil.zone/u/Nickwad)
#### Post date: [March 19, 2020, 1:55pm UTC](https://foil.zone/t/bms-noob-question/7157/1 "2020-03-19T13:55:56Z")

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Will a 13s BMS work on a 12s pack leaving the last balance wire off ?  
Or do they only work for the stated number of cells ?

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### Author: ![Giga](https://foil.zone/letter_avatar_proxy/v4/letter/g/b9bd4f/32.png) [@Giga](https://foil.zone/u/Giga)
#### Post date: [March 19, 2020, 7:19pm UTC](https://foil.zone/t/bms-noob-question/7157/2 "2020-03-19T19:19:57Z")

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depends on the BMS, in general no.  
Leaving one wire off will definitely not work. Normally you either put them on GND or short them somewhere.  
But if it’s not a dirty cheap china BMS, there will be a datasheet with instructions how to use it.  
Most “real” BMS use a TI or LTC chip for cell monitoring which can be configured for a wide range of cell counts, usually from 5-16S. But for configuring you also need a datasheet.