Device and method for monitoring residual electric quantity of battery

Abstract

The invention provides a device and a method for monitoring the residual electric quantity of a battery. The method comprises the following steps: measuring a first open-circuit voltage value, a first conduction voltage value and a first conduction current value of the battery and obtaining an internal resistance value of the battery; respectively measuring and obtaining a second open-circuit voltage value and a third open-circuit voltage value at two different times; comparing the third residual electric quantity percentage value with a preset comparison table or a relation curve, and calculating a difference value between the third residual electric quantity percentage value and the second residual electric quantity percentage value to obtain a residual electric quantity percentage value difference value; measuring a plurality of conduction current values of the battery in the two different time intervals at the same time, and carrying out time integration to calculate coulomb electric quantity; dividing the coulomb electric quantity by the residual electric quantity percentage value difference value to obtain the current maximum electric quantity of the battery; and obtaining the remaining capacity of the battery by using an open-circuit voltage method or a coulomb integral method.

Description

technical field [0001] The invention relates to a battery life detection device, in particular to a device and method for monitoring the remaining power of a battery. Background technique [0002] With the rapid development of electronic technology, terminal devices such as portable electronic products, mobile phones and tablet computers are becoming more and more important in people's daily life. Terminal devices usually need to be charged to maintain operation, so the remaining power of terminal devices The display of is very important to the user. [0003] In addition, the ability to reliably determine the remaining battery power in electric vehicle transportation is highly valued by manufacturers and consumers alike. It is used to calculate the remaining use time and driving distance of the vehicle. In the case of gasoline vehicles, the fuel level can be simply However, in electric and hybrid vehicles and electronic devices, because the battery is used as its power sour...

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Problems solved by technology

[0007] Among them, t is the current charging time, T 0 is the initial time, T n is the current time, Q T0 is the initial power, Q Tn is the current power, I(t) is the charging current, and calculates the power by adding up the power flowing into the battery in ampere-hours. The advantage of the Coulomb integration method is that it can obtain accurate Coulomb power, but the disadvantage of the Coulomb integration method is that it needs to have Accurate current and time measurement capabilities, which usually continue to accumulate and increase the calculated power error due to time and current measurement errors, and the accumulated error can only be resolved when fully charged or fully discharged Eliminate, because it is impossible to know how much power can be charged when the "current maximum power (life)" is unknown, and the current maximum power of the battery will change with different charging and discharging conditions and battery aging, so it cannot be used The preset or last maximum power is substituted, which means that the battery power cannot be accurately calculated, and therefore the remaining time that can be used cannot be effectively estimated

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