Discharge rate - terminal voltage curves

A classical method of representing a discharge curve for a seeondary battery is to plot terminal voltage against time into the discharge at a stipulated battery temperature and constant current discharge rate. Such curves can be prepared at several different battery temperatures in order to establish the effect of temperature on the voltage-time relationship. 

Figure 31.3 shows the relationship between terminal voltage and discharge Lime at various 20 h discharge rates obtained for 6 V and 12 V sealed lead-acid batteries with calcium-lead alloy grids and Figure 31.2 illustrates the same curve for a 1.5V battery. In these curves the nominal capacity of the battery is expressed... 

Figure 31.23 illustrates the charge of terminal voltage as a function of capacity returned (discharged capacity) for a General Electric fully recombining D cell. Typical curves are shown for constant-current discharge rates at the standard conditions noted. 

Larger button cells with rated capacities in the range 35-lOOOmAh are manufactured for direct mounting on printed circuit boards where they are used as standby power sources for CMOS RAMs, reference voltage sources, etc. Fig. 9.10 shows the construction of these cells and the position of the terminal/mounting pins. Projected discharge curves for Catalyst Research Corporation cells are given in Fig. 9.11. 

---