1  The Brief introduction As below :

      Single cell of 3.2V 314Ah is very popular and important Material ,  IT is mainly for the the home storage energy system or the Industry and commerce storage Energy system .. for example : the 51.2V 16KW , 261KW and so on . 

Firstly the manufacture  surely will choose the Grade A of 314Ah. but the different  brand of 314Ah will have different Inner Reisitance

1. )Firstly as below we will check some famous brands  from china. . The Old brands and originally produce them like  will be CATL, CALB . EVE, GOTION ,LISHEN .because BYD is not mainly for the storage energy system , so we dont touch them . 

The data is from the manufacture specifications explains . 

CATL  Brand:

EVE Brand:

Gotion Brand :

LISHEN brand 

CALB Brand:

All of the above is just list  for show, not comments ..

About CALB the IR is looks higher . but  normally will be 0.20-0.25 . few situation  it will reach 0.32

2)  secondly the small difference on the IR

           There is some different measuring way and the basic Principle like some manufacture will focus more on the Inner resistance . but some other manufacture will focus on the balance of the whole usage between the cycle life and the IR . So the Inner Resistance will be very more important . but not the unique standard . and some conditions , we need to focus the actual usage 

2 .the usage  of IR For the manufacture of the lifepo4  Battery pack, Storage  Energy system 

In a word . above is the basic information ,  if you will  buy  the  3.2V  314Ah lifepo4 (LFP) single cells or DIY the  Battery , hope it will help you . if there is any other question pls let me know 

info@hzhim.com