Nami
New Member
- Joined
- Jan 13, 2022
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Battery management system BMS in addition to preventing battery pack overcharging and overdischarge,
Good balancing is required to maintain the consistency of the battery pack.
At present, almost all BMS in the market have the balancing function, which is mainly divided into passive balancing and active balancing.
☆ Active equalization (lossless equalization)
Active equalization equalizes the whole set of voltage by transferring the high energy of a single cell to a battery with low energy of a single cell in a way of energy transfer, with little energy loss involved in the transfer process.
1.Start Equilibrium Conditions
Batteries start to balance whenever the pressure difference is greater than the set value, whether they are charging, discharging or resting, so as long as there is an active balance with the pressure difference, it should work 24 hours a day until the pressure difference is less than the set range.
2.Balanced current
Since active balancing is the way of energy transfer and does not heat up, all balanced currents can be large without affecting heat loss. Generally, active balanced currents can be 1~2A more common.
Since active equalization is not limited by charging time, has a longer equalization time, and has a larger equalization current, it is suitable for use in large capacity battery packs.
☆Passive Equilibrium (Lossy Equilibrium)
Passive equalization generally discharges batteries with higher voltage by means of resistance discharge, releasing energy in the form of heat, balancing the whole set of voltage, and gaining more charging time for other batteries.
1.Start Equilibrium Conditions
Passive equalization can start discharge equalization only when the battery is close to full voltage, so the start-up equalization time of passive equalization is relatively short, from full battery to full-up, and generally several hours equalization time depending on the charger.
2.Balanced current
Because passive equalization is a resistance-consuming equalization, the energy consumed is released in the form of heat, so charging BMS during the equalization process will heat up, resulting in a balanced current that cannot be set too high, otherwise the battery pack temperature will be too high. Generally, the passive equalization current is from 35mA to 200mA, the larger the equalization current, the more severe the fever.
If the equalization current is small, the efficiency of the power balance in large capacity battery packs with large power differences is low. It takes a long time to reach the balance, and there is a scratching sensation in the application. Passive equalization circuit is simple, low cost and suitable for low capacity battery packs.
☆Advantages of active equalization method:
1) The active equalization circuit has high equalization efficiency.
2) Balance during charging, discharging and static process.
3) The balance current is large and the balance speed is fast.
Good balancing is required to maintain the consistency of the battery pack.
At present, almost all BMS in the market have the balancing function, which is mainly divided into passive balancing and active balancing.
☆ Active equalization (lossless equalization)
Active equalization equalizes the whole set of voltage by transferring the high energy of a single cell to a battery with low energy of a single cell in a way of energy transfer, with little energy loss involved in the transfer process.
1.Start Equilibrium Conditions
Batteries start to balance whenever the pressure difference is greater than the set value, whether they are charging, discharging or resting, so as long as there is an active balance with the pressure difference, it should work 24 hours a day until the pressure difference is less than the set range.
2.Balanced current
Since active balancing is the way of energy transfer and does not heat up, all balanced currents can be large without affecting heat loss. Generally, active balanced currents can be 1~2A more common.
Since active equalization is not limited by charging time, has a longer equalization time, and has a larger equalization current, it is suitable for use in large capacity battery packs.
☆Passive Equilibrium (Lossy Equilibrium)
Passive equalization generally discharges batteries with higher voltage by means of resistance discharge, releasing energy in the form of heat, balancing the whole set of voltage, and gaining more charging time for other batteries.
1.Start Equilibrium Conditions
Passive equalization can start discharge equalization only when the battery is close to full voltage, so the start-up equalization time of passive equalization is relatively short, from full battery to full-up, and generally several hours equalization time depending on the charger.
2.Balanced current
Because passive equalization is a resistance-consuming equalization, the energy consumed is released in the form of heat, so charging BMS during the equalization process will heat up, resulting in a balanced current that cannot be set too high, otherwise the battery pack temperature will be too high. Generally, the passive equalization current is from 35mA to 200mA, the larger the equalization current, the more severe the fever.
If the equalization current is small, the efficiency of the power balance in large capacity battery packs with large power differences is low. It takes a long time to reach the balance, and there is a scratching sensation in the application. Passive equalization circuit is simple, low cost and suitable for low capacity battery packs.
☆Advantages of active equalization method:
1) The active equalization circuit has high equalization efficiency.
2) Balance during charging, discharging and static process.
3) The balance current is large and the balance speed is fast.