The wider system and it’s requirements are fundamental to the design of a battery pack. This means we need to understand the power electronics and how they operate, what they require, their failure modes and any legislative requirements.
Different applications have different system requirements, duty cycles and use cases.
- Mobile phone
- Home energy storage
- Electric vehicle
- Grid storage
Battery Pack Metrics
A Pugh Matrix is a good way of making a high level comparison between applications and the key pack metrics.
In the case of mobile consumer products such as a mobile phone the lifetime of the battery is perhaps not as important as it would be in the case of a grid storage system. The mobile phone has a 2 to 3 year life before most are upgraded. A grid storage system needs 20 years of operation.
Road Vehicle Power Demand
Let’s look at the road vehicle power demand for the simple steady state condition. We will look at the tractive effort and power required:
- Aerodynamic forces
- Rolling resistance
- Hotel loads
Cold Climate EV Range
There are a number of factors that will impact the vehicle range and it is not totally due the battery as this is a two axis problem with the vehicle energy consumption also playing it’s part. Hence, let us break this into battery energy and vehicle energy consumption at the highest level and then list the factors under each.
- Vehicle energy consumption
- Battery energy
Battery Value Chain
The battery value chain looks at the whole eco system from mining the raw materials through to recycling.