What is the difference between BL-4C and BL-5C?

BL-4C has GND-to-BSI resistance of 75 kOhm with capacity of 860 mAh.It runs at 3.7 V

BL-5C has two series:

1. BL-5CA has GND-to-BSI resistance of 47 kOhm with capacity of 700 mAh.It runs at 3.7 V
2. BL-5CB has GND-to-BSI resistance of 30 kOhm with capacity of 800 mAh.It runs at 3.7 V