Page 154 - Lindens Handbook of Batteries

MATHEMATICAL MODELING OF BATTERIES 6.7

1.6
Charge
(Current = 4, 8, 16, 32, 64 A)
1.5

1.4
V, cell voltage (V) 1.3

1.2

Discharge
1.1 (Current = 4, 8, 16, 32, 64 A)

1
0 10 20 30 40 50 60 70 80
Q, capacity (Ah)

1.6
Current = 4, 8, 16, 32, 64 A
1.5 Charge curves

Average cell voltage (V) 1.3
1.4

1.2
Discharge curves
Current = 4, 8, 16, 32, 64 A
1.1
Experiment
1
0 10 20 30 40 50 60 70 80 90 100
Capacity, Ah
FiguRE 6.4 Model predictions for a NiMH cell. Results from a model using the empiri-
cal equivalent circuit shown in Fig. 6.3 are shown in the upper plot and the corresponding
experimental data on the lower plot. 4

Similar results can be obtained for constant power loads by replacing the current (I) in Eq. (6.7)
with P/V where P is the power set by the load. Figure 6.5 shows comparison of model versus experi-
mental data for the parameter set shown in Table 6.2 for a lithium-ion cell, using the same set of
equations described above.