Charge characteristic, nickel cadmium batteries

Figure 19.11 Voltage characteristics nickel-cadmium battery 1, charged 2, discharged (Courtesy of Chloride Batteries)...

Figure 20 shows the charge-discharge characteristics of the AA-size nickel-metal hydride battery in comparison with the nickel-cadmium battery produced by Sanyo Electric. Its capacity density is 1.5 to 1.8 higher than that of nickel-cadmium batteries. 

Fig. 6.4 Discharge (a) and charge (b) characteristics of a typical 900 Ah nickel-cadmium battery as a function of rate...

The characteristics of nickel/metal hydride batteries are very similar to those of sealed nickel/cadmium batteries. The cell voltage differs by only 20 mV, and charging as well as discharging performance are so alike that both battery systems can be replaced by each other in all normal applications. The discharge curves in Fig. 1.38 confirm this. 

Charging Nickel/Cadmium Batteries According to the W Characteristic... 

FIGURE 26.7 Charge and discharge characteristics of nickel-cadmium batteries at 25°C. (a) Pocket plate battery, high rate, (b) Plastic-bonded plate battery, high rate. 

Most of the operating characteristics of the sealed nickel-metal hydride battery on discharge are similar to those of the nickel-cadmium battery. The sealed nickel-metal hydride battery, however, does not have the very high rate capability of the nickel-cadmium battery. In addition, the behavior of the two systems on charge, particularly on fast charge, is different. The nickel-metal hydride battery is less tolerant of overcharge and requires control of the cutoff of the charge, which may not always be required for nickel-cadmium batteries. 

The recharging characteristics of the nickel-metal hydride battery are generally similar to those of the sealed nickel-cadmium battery. There are some distinct differences, however, particularly on the requirements for charge control, as the metal hydride battery is more sensitive to overcharge. Caution should be exercised before using the same battery charger interchangeably for both types of batteries. 

Figure 2.8 shows the charge characteristics when charging is performed at a constant current In nickel-cadmium batteries, characteristics such as cell voltage, internal gas pressure, and cell temperature vary during charging, depending... 

Figure 2.10 shows the charge-discharge cycle characteristics. As shown in this figure, nickel-cadmium batteries exhibit excellent cycle characteristics and no noticeable decline is observed after 1000 charge-discharge cycles. 

Figure 31.49 Self-discharge charge retention characteristics of Varta sealed nickel-cadmium batteries (Courtesyof Varta)...

---