Batteries Ampere-hour capacity

Battery ampere hour capacity (5 A rate) with time available for rechatge Starting current (A)... 

Cold crank performance, battery life expectancy, and freedom from maintenance are generally co-affected by the separators, whereas ampere-hour capacity remains largely unaffected at a given separator thickness. The properties of the different leaf and pocket separators are compared in Table 10. These typical separator properties (lines 1-4) are reflected in the electrical results of battery tests (lines 5-8). The data presented here are based on the 12 V starter battery standard DIN 43 539-02 tests based on other standards lead to similar results. 

Ampere-hour capacity in percent Figure 17.2 Charging and discharging of a lead-acid battery. 

The size of a battery is defined as its ampere-hour capacity, since capacity is related to charge... 

Aluminium conductor steel reinforced. American Gear Manufacturer s Association Ampere-hour capacity of batteries. 

This energy is measured not only in Joules (1 J = 1 W s) but also in watt-hours (1 Wh = 3600 J.). Both the maximum ampere-hour capacity and the watt-hour energy depend on the amount of reactants in a battery at the start of discharge. As the discharge current increases, both the discharge voltage and the reactant utilization coefficient diminish. A number of attempts to find a relationship between the actual battery capacity and the discharge current were reported. An approximation found in 1897 by Peukert for lead acid batteries is sometimes used ... 

The parameter ampere-hour capacity of a battery is more common (and mostly used in battery specifications) than the parameter watt-hour energy as it is easier to measure. 

The most important group of compound batteries are metal-air batteries in which readily oxidized metals are used as anodes and so-called air-breathing electrodes are employed as cathodes. The cathode reactant—air oxygen—is readily available everywhere and need not to be stored in the battery, thus, providing a considerable economy in the battery mass and volume and a corresponding increase of the specific ampere-hour capacity... 

Another problem is that of balance between single cells in a multicell battery. Such batteries are balanced when all cells (preferably of the same type) have the same capacity and the same state of charge (SOC). In case of a mismatch between cells connected in series the battery s ampere-hour capacity is determined by the cell with the least available ampere-hour capacity. In case of cells connected in parallel, a failure (e.g., short circuit) of one of the cells can lead to the failure of the whole battery. 

Advantages. The advantages of the lead-acid battery are a lower initial cost, high ampere-hour capacity, and low resistance to self-discharge. The nickel-iron-alkaline battery is desirable because of its longer life expectancy, resistance to physical damage, noncorrosive electrolyte (KOH), and more rapid and less critical recharge rates. 

SOC This represents the percentage of its total ampere-hour capacity stored in a battery. 

The theoretical capacity of a cell is determined by the amount of active materials in the cell. It is expressed as the total quantity of electricity involved in the electrochemical reaction and is defined in terms of coulombs or ampere-hours. The ampere-hour capacity of a battery is directly associated with the quantity of electricity obtained from the active materials. Theoretically 1 gram-equivalent weight of material will deliver 96,487 C or 26.8 Ah. (A gram-equivalent weight is the atomic or molecular weight of the active material in grams divided by the number of electrons involved in the reaction.)... 

The battery is not discharged to zero volts and all of the available ampere-hour capacity is not utilized. 

The charging efficiency is high for a VRLA battery. The distinctly high ratio of plate surface area to Ampere-hour capacity allows for higher charging rates and, therefore, efficient charging. 

The relationship of the ampere-hour capacity (expressed as a percentage of the eapacity at 20°C on a discharge at the 0.2C rate) of the sealed niekel-metal hydride battery and the discharge temperature and current (expressed in C rate) is summarized in Fig. 29.7. 

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