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THE TECH Creatively displaying battery cell data In an effort to find new and innovative ways to display cell data - and in collaboration with a colleague who is a BMS expert from a major Li-ion cell manufacturer we developed a new graphical design approach dubbed “Flubber.” At this point Flubber is only a concept; it doesn’t exist in any testing products. This discussion is intended to open up ideas and inspire other HMI designers to think differently about the wealth of information that comes from the BMS and consider other ways to help test engineers read a pack’s data more quicker. Flubber appears as a histogram that has been smoothed

out with a spline function. It represents the number of cells in a battery pack. The Y-Axis plot shows the battery cells voltage range from 2.0 V to 4.0 V, and the X-Axis represents the cell’s SOC levels. The goal is to ensure that the battery cells stay close to each other while moving across the X-Axis. This would suggest that the cells are well-balanced throughout their usage (charging or discharging). If the batteries are well-balanced and fully charged, then Flubber will be at a sharp peak to the right of the plot (Figure 1). If they are completely discharged and balanced, then Flubber will be flat and furthest to the left (Figure 2).

Figure 1: Well-balanced and fully charged

Figure 2: Well-balanced and discharged

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DEC 2013 35

CHARGED Electric Vehicles Magazine - Iss 11 DEC 2013  

CHARGED Electric Vehicles Magazine - Iss 11 DEC 2013