Discharging a Battery

If a current flows, for example while discharging a battery, a shift in the potential of the single half-cell is measured. This deviation is called over-potential, rj [12], Thus, the real potential A real has to be calculated with Eq. (39) ... 

Fig. IE Loss of energy as a result of irreversibility in processes occurring at a finite rate. (a) expansion and compression of gas. (b) charging and discharging a battery. Dashed lines correspond to the reversible paths.

Callow Tanks.— These tanks are illustrated in Figs. 9 and 10. For separation, where a clean liquid overflow is desired, the use of the smaller sizes shown in Fig. 9 is not to be recommended. As an inspection of the capacity table accompanying Fig. 9 will show the tanks have a small capacity and are suitable to small operations. Used in batteries they occupy more space than a single tank of equal settling area and capacity and there is the extra annoyance and expense in insuring the free running of the discharges. A battery of 50 8-ft. tanks requires not... 

Deep Discharge - Discharging a battery to 20 percent or less of its full charge capacity. 

The energy delivered during discharging a battery for t hours is... 

The amount of time it t ikes to discharge a battery depends upon the battery capacity C expressed in milliamp hours (mAh) (more is better) and the amount of current drawn by the load. Battery charge and discharge currents are normalized with respect to battery capacity and are expressed in terms of C-rate. C-rate = C/1 hour, e.g., to a 150-mAh battery has a C-Rate of 150 mA. The current corresponding to 1C is 150 mA and O.IC, 15 mA. For a given ceU type, the behavior of cells with varying capacity is similar at the same C-rate. More in depth information about batteries can be found in the Handbook of Batteries (Linden, 1995). 

Which of the following is not accompanied by an increase in the entropy of the system (a) mixing of two gases at the same temperature and pressure, (b) mixing of ethanol and water, (c) discharging a battery, (d) expansion of a gas followed by compression to its original temperature, pressure, and volume. 

This characterization is often done by way of the galvanostatic method, because it is difficult to charge or discharge a battery to a given open-circuit voltage to obtain a given SOC. However, the SOC can be approximately calculated by integrating the current over time. In the case of lithium-ion... 

An equalized charge condition on single cells before discharging a battery is important in order to avoid deep discharging or reverse charging. 

The energy density is a common measure in evaluating battery systems. Specific energy stored (in Wh kg ) in a battery is measured by discharging a battery at an appropriate current ... 

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