Main components of a Li-ion battery include:

Cell modules

Interconnects

Battery Management System (BMS)

Heater or cooling system (when required)

Ballast (when necessary)

External casing

The table below shows the equivalent voltages for Lead Acid and Li-ion

Lead Acid	Lithium-ion
24 V	25.6 V
48 V	51.2 V
80 V	76.8 V

*Image courtesy of Midac Batteries