Lead acid battery remaining capacity computation method and monitoring system

Abstract

The invention discloses a lead acid battery remaining capacity computation method and a monitoring system. The method comprises the following steps: when a battery is located at an idle state, computing the remaining capacity at the current moment based on an open-circuit voltage method and battery idle duration segment; when the battery voltage collected at the current moment is less than the remaining capacity equivalent voltage of the previous moment, computing the remaining capacity of the current moment by dynamically updating the discharge time; when the battery voltage collected at thecurrent moment is greater than the remaining capacity equivalent voltage of the previous moment, judging whether the battery voltage collected at the current moment is greater than and equal to the product of the battery monomer reset voltage and the battery monomer number; and when the battery voltage collected at the current moment is equal to the remaining capacity equivalent voltage of the previous moment, setting the remaining capacity of the current moment as the remaining capacity of the previous moment. The remaining capacity can be corrected by dynamically updating the discharge timeand utilizing the battery idle duration segment, and the high measurement precision can be provided under different load working conditions.

Description

technical field [0001] The invention relates to the technical field of SOC, in particular to a method for calculating the remaining power of a lead-acid battery and a monitoring system. Background technique [0002] There are two main calculation methods for the current forklift SOC: [0003] a. Combination of open circuit voltage + empirical method: Specifically, the real-time remaining power of the forklift is calculated by combining the open circuit voltage method with a 1% power drop in 3 minutes (experience). The advantages of this method are simple algorithm and strong portability. However, the discharge time of this method is a fixed value, which is more suitable for storage vehicles; the actual field data shows that for forklifts such as counterbalance trucks under different load conditions, the battery discharge time can vary several times, and the accuracy of the algorithm is low. large error; [0004] b. Open circuit voltage + time integration method: This metho...

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Problems solved by technology

[0004] b. Open circuit voltage + time integration method: This method has high calculation accuracy, but it has very high requirements for controllers and sensors, the algorithm is complex, and the threshold is high

On the one hand, this method requires high computing performance of the controller, and on the other hand, requires high accuracy of the current sensor, resulting in increased hardware costs; and once the sensor accuracy fails, the calculation will have a large error

[0005] To sum up, the open circuit voltage method is generally only suitable for use when the battery has no load, and the calculation accuracy is high at this time, but when the battery output current drives the load, the remaining power can only be estimated by using the empirical method, which inevitably introduces cumulative errors

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