23
Design Overview
A battery pack is a system of multiple components and functions and its design involves the application of
knowledge and practice in the electrochemical, electrical, mechanical, thermodynamic, and control fields. The
following sections summarize the various stages of a battery pack design, covering specific aspects of the A123
cells which may be unique from other cells.
1.
The first step in the design of the pack is to determine the
configuration of cells, i.e. how many cells overall, how many are in
series, and how many are in parallel. This is the foundation of the
design process, since all other design decisions follow from the cell
configuration.
2.
The second step is to design a mechanical structure around the cells to
support and protect them. This step requires knowledge of electrical,
mechanical and thermodynamic requirements and properties of the
cells, application, and the materials used in the pack.
3.
The third step is to design the protection of the cells, particularly
electrical protection. The pack must be protected from inadvertent
short circuits internal and external to the pack as well as excessive
charging and discharging imposed on its terminals.
4.
The fourth step is to design a control system that monitors and
manages the cells, keeping them from being damaged and maintaining
the pack at peak performance.
5.
Finally, a pack performs best when it is used properly. The final section
of this chapter describes how to charge and discharge the battery pack
to make it perform its best.
Cell Configuration
Structure
Cell Configuration
Protection
Structure
Cell Configuration
Control
Protection
Structure
Cell Configuration
Use
Control
Protection
Structure
Cell Configuration