2. Battery Topology Terminology
Energy storage systems are hierarchical in nature. Nuvation Energy has adopted the following
definitions for battery pack topology:
Cell
A Cell is the smallest unit of energy storage distinguishable by the battery management system.
One Cell, as defined from the perspective of the BMS, may actually consist of one or more
electrochemical cells connected in parallel. This subtlety is reflected in the nomenclature for
completeness. For example, a "1p" Cell refers to a single electrochemical cell, while a "2p" Cell
refers to two electrochemical cells connected together in parallel. From the perspective of the BMS,
these topologies appear identical except for the capacity of the Cells.
Group
A Group is a set of Cells connected in series and managed together. For example, 12 "1p" Cells in
series are referred to as a "12s1p" Group, while 16 "2p" Cells in series are referred to as a "16s2p"
Group. Grouping of Cells is highly application-specific and is defined in how BMS hardware
interfaces are physically wired up to Cells.
Stack
A Stack is one or more Groups connected in series. For example, five "14s2p" Groups connected in
series could be described as a "5g14s2p" Stack. However, it is far more common to describe it as
a "70s2p" Stack.
Bank
A Bank is one or more stacks connected in parallel. For example, three "70s2p" Stacks connected
in parallel are referred to as a "3x70s2p" Bank.
Pack
A Pack is one or more Banks connected in series.
Nuvation Energy High-Voltage BMS - Product Manual
Document ID: NE-PM-003
3
Rev 1.2, 2021-03-03
Curie Update 1