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BMS with Li-Battery


I am going to develop a standalone system and use Li-ion battery for the power source.

In addition, I need to connect several packs of Li-ion battery in parallel to maximize the standby period.

(P.S, in this system, there is no charging functions as the batteries will be received  for charging.)

And my concern is the system should be implemented a battery management system for a batter energy control and safety.

Safety is the mainly concerning point as I think it is dangerous to connect those packs of batteries in parallel, am I right?

Is there any controlling ICs or circuits of such kind of BMS?

I have no ideas for that...



  • Kaho,

    I am not familiar with how parallel batteries are monitored, balanced and protected.

    Analog Devices has some devices for series connected LI batteries such as the AD7280A and AD8280.

    ADI offers the main components required for a complete Li-ion battery monitoring and protection system: 

    • Voltage measurement device - monitors and balances the cells (AD7280A
    • Current measurement device - monitors the cell stack’s current (ADuC703x or AD821x
    • Isolator - brings the measurement signals across the high-voltage barrier to the battery management unit (ADuM140x or ADuM540x
    • Safety monitor - enables creation of a fail-safe circuit and safe environment to the user (AD8280
    • Battery management unit – controls and manages battery functions to optimize operation (Blackfin ADSP-50x)

    Good luck and thanks for looking at ADI for solutions.



  • If there is no charging you could connect each pack through a suitable diode to a common battery rail.  This would prevent one pack charging another should they be charged to different levels or of a different age.  I would suggest that each pack makes use of monitoring such as the solutions Luca suggested, particularly with regard to monitoring the stack current, voltage and temperature.  Should any pack experience over discharge, increased temperature or exceed its discharge current specification it should be disconnected from the circuit.

  • Dear Luca and Tim,

    So, does it mean I also need to develop a switching circuit?

    Is it something called OR-ing circuit?



  • An ORing circuit should work for this application as you are trying to maximise standby rather than the peak current from the battery pack. There is a good example using the AD8619 opamp and a MOSFET to overcome the losses associated with using a diode at 

  • Thanks Tim for that suggestion.

    I think with batteries you would have to be able to charge them separately from the oring circuit, and guarantee no reverse current through the oring circuit.

    I am not an expert on the subject so I just wanted to rsise thst as something to pay attention too.


  • Thanks to all,

    I am now going to develop some current sensing circuit and use a MOSEFT to control the power input,

    If there are any errors detected, like over current flowing or low voltage, the MOSEFT is controlled to cut the power.



  • Kaho,

    in case you are interested we have some ICs that can handle some of the functions you are looking to implement:

    ADM1171:  2.7 V to 16 V Hot Swap Controller with Current Sense Output

    ADM1275:  Hot Swap Controller and Digital Power Monitor with PMBus Interface
    ADM1276:  Hot Swap Controller and Digital Power and Energy Monitoringwith PMBus Interface

    ADM4073:  Low Cost, Voltage Output, High-side Current Sense Amplifier

    AD8420:  Wide Supply Range, Micropower, Rail-to-Rail Instrumentation Amplifier

    AD8214:  Fast Response, High Voltage, Current Shunt Comparator

    AD8207:  Zero Drift, High Voltage, Bidirectional Difference Amplifier

    Best Regards,


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    EZ Admin