The capacity of the lead-acid battery has a size, which determines the working time and life of the battery. The lead battery capacity is reduced with the discharge ratio. When it comes to the capacity, the time limit or magnification of the discharge must be specified. The battery capacity is different from the discharge rate or the magnification.First, the impact of the discharge rate on battery capacity
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The lead battery capacity is reduced with the discharge ratio. When it comes to the capacity, the time or magnification of the discharge must be specified. The battery capacity is different from the discharge rate or the magnification.
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(1) Relationship between capacity and discharge rate
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For a given battery, discharge at different time rates, there will be different capacities, the following table is the rated capacity of the Huada GFM1000 battery at normal temperature at normal temperature.
(2) Reasons for the decline in capacity when high-magnification discharge
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The higher the discharge magnification, the larger the discharge current density, the more uneven distribution of the current on the electrode, and the current is preferentially distributed on the nearest surface of the main body electrolyte, thereby preferentially generate PBSO4 in the outermost surface of the electrode. The volume of PBSO4 is larger than PbO2 and Pb, so that the discharge product is blocked by the porous electrode, the electrolyte does not sufficiently supply the internal reaction of the electrode, and the internal material in the electrode cannot be fully utilized, so that the capacity of high magnification is lowered.
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(3) Depth relationship between discharge current and electrode
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At a high current discharge, the active material is limited in the thickness direction, the smaller the current, the smaller the degree of active substance is utilized, the smaller the capacity given by the battery. When the electrode is discharged at a low current density, when i ≤ 100A / m2, the active material has a depth of 3 × 10-3 m-5 × 10-3m, and the inner surface of the porous electrode can be taken completely. When the electrode discharges at a high current density, when I ≥ 200A / m2, the active material has a sharp drop, about 0.12 × 10-3m, and less use in the depth of the active substance, when the diffusion has become a decision of restriction capacity factor.
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At the current discharge, due to the presence of polarization and internal resistance, the end voltage of the battery is low, and the voltage drop loss is increased, so that the battery end voltage is low, and the capacity is also affected.
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Second, the effect of temperature on battery capacity
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The ambient temperature has a large amount of capacity of the battery, and the capacity is reduced as the ambient temperature is lowered. The battery capacity change at 1 ° C in ambient temperature is called the temperature coefficient of the capacity.
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According to national standards, if the ambient temperature is not 25 ° C, the measured capacity is required to convert the actual capacity Ce at 25 ° C based in the following formula, and its value should meet the standard.
CE = CT / [1 + K (T-25 ° C)]
In the formula: T is ambient temperature at the time of discharge
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K is a temperature coefficient, and the capacity of 10HR is k = 0.006 / ° C, and the capacity of 3HR of 3HR is k = 0.008 / ° C, and the capacity of 1HR is k = 0.01 / ° C.
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Third, the calculation of the capacity of the valve controlled battery
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The actual capacity of the valve-controlled lead-acid battery is related to the discharge system (discharge ratio, temperature, termination voltage) and the structure of the battery. If the battery is discharged at a constant current, discharged to a predetermined termination voltage, the actual capacity CT = discharge current I × discharge time t, the unit is AH. Recommend: LiFePO4 Battery Manufacturer Energy storage battery Manufacturer Integrated machine energy storage battery series Manufacturer Lead lithium battery Manufacturer Outdoor Backup Battery Manufacturer Portable outdoor power supply Manufacturer Power battery Manufacturer Powerwall LiFePO4 Battery Manufacturer Battery rack Manufacturers Telecom LiFePO4 Battery Manufacturer Wall mounted battery storage Manufacturer China Lifepo4 Battery
