18650 Cell voltage monitoring

[Nitin25]

Does anyone worked on battery monitoring system ?

While monitoring 18650 cells How to sense individual cell voltage with the help of microcontroller. As microcontroller accept up to 5 volt.
So if I connect few number of cells in series voltage crosses the 5 volt limit. Voltage divider circuit is fine at certain series cells. But it has very very bad efficiency.
So anyone have idea how to measure individual cell voltage ??

[beanflying]

Firstly Welcome.

Secondly DO NOT CROSS POST and start multiple topics about one project.

Hello ,
Could you help me to design battery monitoring system.
How I can monitor individual cell if more number of cells connected in series.As microcontroller works on 5 volt.
So how to monitor those cells.
Please help me out !!

Thirdly NO I will not design you a system in private because you sent me a PM. 

Fourthly I and others may help you with your project if you give some details of it. So how many 18650 cells what BDLC motor and controller ...... We can not read minds. 

[digsys]

Does anyone worked on battery monitoring system ?
While monitoring 18650 cells How to sense individual cell voltage with the help of microcontroller. As microcontroller accept up to 5 volt.
So if I connect few number of cells in series voltage crosses the 5 volt limit. Voltage divider circuit is fine at certain series cells. But it has very very bad efficiency.
So anyone have idea how to measure individual cell voltage ??

This is a BMS I designed and use on EVs, mostly solar cars. A few teams have used it as well. All circuits and layouts are provided free to use.
The main IC is a differential op-amp, capable of monitoring voltages of up to +/- 250VDC difference. That's app 50+ series Li cells.
https://pbase.com/digsys/image/161061565
More pix at https://pbase.com/digsys/projects
Hook it up to any LV MPU etc

[Yainakorn]

I think there is a confused answer to this post.