I Have used ABLIC IC S-8261 for battery protection

I have added a series resistance of 90milli ohm so that the over current detection voltage is reached at 0.6A will this cause any problems also the. The overcurrent detection voltage is measured between VM and VSS will the grounding of negative terminal of the battery back affect the detection.
Datasheet attached .

 

Welcome to AAC.

You cannot have the S2 output grounded as well as the battery -ve. Only one can be ground, else you are bypassing the MOSFET charge/discharge protection. If battery -ve is 'ground' then the input/output is floating between S2 and Batt +ve. More conventionally you would make the battery floating and make S2 ground for both charge and discharge.

 

Welcome to AAC.

You cannot have the S2 output grounded as well as the battery -ve. Only one can be ground, else you are bypassing the MOSFET charge/discharge protection. If battery -ve is 'ground' then the input/output is floating between S2 and Batt +ve. More conventionally you would make the battery floating and make S2 ground for both charge and discharge.

In the datasheet they have
Connected the VSS to ground.Should i leave the the VSS floating and ground EB-.

 

Should i leave the the VSS floating and ground EB-.

Yes, then both your load and charger are referenced to that.