Nowadays, the 12V charger is generally used by three-stage intelligent charging mode, and the circuit design principle is often designed for constant current switching constant current constant voltage power supply. What is three-stage charging? Let's first learn about the concept of 12V chargers. Forklift battery1. Floating: The battery is charged, due to the presence of impurities in the electrolyte and polar plate, a partial discharge is formed on the plate, so that the battery is in a standby state in a full state, the battery is parallel, connected in parallel On the DC bus, the 12V charger except for the frequent DC load, it also gives the battery appropriate charging current, which is called floating charge.
2, all charge: All charge is equalization charging. The so-called balanced charging is the charging of the balanced battery characteristics, refers to the battery-end voltage imbalance during the use of the battery, and the temperature difference, etc., in order to avoid this imbalance trend, it is necessary to increase the battery. The charging voltage of the group activates the battery.
The charger voltage is generally 14.5V, and the unit charge is not more than 10 hours. The battery needs to be balanced in the following situations.
1. The energy release of the battery exceeds 15% of the total capacity after the electric power outages.
2, the battery is in the long-term floating state (stable grid, long-term non-stop).
3, in the battery pack, there is a backward battery, and the monomer voltage is lower than 2.2V in the floating state, and the new battery is replaced.
Three stages of charging first:
First, the first phase ---- constant flow section, when the battery voltage is low, in order to avoid the charging current is too large, the battery should be limited to the charging current, but in order to shorten the charging time, the allowed maximum current should be used. Charging, so a constant current charge is used. During the constant current charging, the 12V charger is always charged with a constant current (typically 0.18 --- 3c, C for battery capacity). During the charging process, the battery voltage will be more charged until it is rising to 2.45V. Then transfer to the next stage charging. The constant current charging phase is the main charging stage. The battery has been charged into the electric volume of about 85 ---- 90%, the constant current charging phase, the battery voltage exceeds the hydrogen-proof voltage of 2.35V / grid, which is that the electric vehicle battery will lose water. reason. Only because the battery quality and the 12V charge quality are different, the degree of loss of water will also have a large difference.
Second, the second phase -------constant pressure section, when the constant current charging ends, the 12V charge output voltage will not change, keep this constant voltage to charge the battery, during constant voltage charging, battery The voltage is getting higher and higher, and the current will be smaller. When the charging current drops to 0.5C, the constant voltage charging ends, and then transfer to the next stage charging, the constant voltage charging stage is supplemented with the battery, and the battery has been Basically full of. The voltage of the constant pressure phase is too high, which will cause excessive loss of water and excessive charging, and the voltage is too low will lead to undermation and battery vulcanization. Therefore, it should strictly control the voltage and current of its charging. Some chargers have increased the charging current at this stage, and the negative pulse discharge function is added to eliminate the concentration phenomenon of the surface of the battery polar plate, and improve the battery power and reduce the temperature rise, alleviate the battery. Excessive water, thereby further shortening the charging time, this is the negative pulse charge. Some chargers will change smooth DC electricity when charging to pulse current charging. This charger is called a pulse charger. The pulse charger utilizes the charging characteristics of the short-term high voltage large current, which improves battery powered capacity, and the effect of sulfur.
Third, the third stage ------ floating segment, floating charging is also called trickle charging, the floating charging stage is actually constant, only low charging, small current, maintenance charging, allowed Long-term charging. At this stage 12V charger, the charging voltage is generally controlled around 13.6--13.8V, and the charging current is relatively large, generally 0.01 ---- 0.03C. Through trickle charging, the battery is charged to be close to 100%. Excessive current is not enough to make up for the battery's self-discharge, excessive current can cause overcharge and loss of water. Small current long-term charging, has the effect of eliminating the vulcanization of the negative electrode plate.
Article from: http://www.brcpower.com/ 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
