A stepwise constant current charging and discharging method

Abstract

The invention relates to a stepped constant current charging-discharging method which comprises the following steps: 1, constant-voltage current-limiting charging: (1) after voltage of a battery pack reaches even charging voltage, a battery charger converts to constant-voltage charge; (2) after charging current is less than floating charge current, the above constant-voltage charge is still maintained until the end of countdown; 1.3, floating charge: after timing of floating charge time, the battery charger converts to floating charge phase; and 2, constant-current discharging process: a PWM modulation circuit opens a channel No.1, and duty ratio is gradually and rapidly increased from 0% fully-closed state to 100% state; and channels No. 2, No. 3 and No.4 are opened in the same way; and a channel No.5 is opened, and duty ratio is gradually increased from 0% to a set value. The invention has beneficial effects as follows: the principle is simple, effects are good, scalability is good, response speed is fast and current stabilization precision is high; performance is stable and reliable, the environment is protected, and there is no peculiar smell; different voltage ranges and current ranges can be satisfied; stepless adjustment of current can be realized; and constant current precision is not easy to interrupt by the external environment.

Description

technical field [0001] The invention relates to the field of storage batteries, and mainly relates to a stepped constant current charging and discharging method. Background technique [0002] The current constant current method adopted by mainstream "battery discharge instrument" manufacturers, 1. PTC constant current method: use the "resistance-temperature" characteristic of PTC, adjust the PTC temperature by controlling the fan speed, and then adjust the PTC resistance value, so as to control the discharge current. Realize constant current. Advantages: simple structure, easy to implement, good self-protection characteristics, light weight; Disadvantages: poor accuracy of steady flow, easily affected by the environment (such as: air flow, ambient temperature, etc.); cannot be adjusted from a small current, etc. 2. "8421" code combination method: multiple channels are connected in parallel, and the discharge power of each channel is combined according to the "8421" code for...

AI Technical Summary

Problems solved by technology

Advantages: simple structure, easy to implement, good self-protection characteristics, light weight; Disadvantages: poor accuracy of steady flow, easily affected by the environment (such as: air flow, ambient temperature, etc.); cannot be adjusted from a small current, etc.

Advantages: simple principle, easy implementation, high reliability; Disadvantages: limited by the minimum power channel, stepless adjustment of current cannot be realized, and the accuracy of steady current is poor

Advantages: good steady flow accuracy, fast steady flow speed, less affected by the environment; Disadvantages: greatly affected by volume and weight, difficult to achieve high current

For example, the power battery focuses on "cycle life" and has a thick plate; while the battery used as a backup power supply focuses on "float charge life" and the plate is relatively thin. Therefore, frequent deep charging and discharging of the backup battery that focuses on "float charge life" will greatly shorten its service life

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