Intelligent Cell Balancing
The Orion BMS uses an intelligent approach to balancing that seeks to maintain and improve balance from cycle to cycle. Unlike lead-acid batteries, lithium ion batteries tend to stay in balance once initially balanced, as long as an intelligent approach is used to maintain the balance.
The Orion BMS uses passive balancing to remove charge from the most charged cells in order to maintain the balance of the pack. The passive shunt resistors dissipate up to 200mA per cell. While that amount may seem small, that current is more than sufficient for maintaining balance in very large battery packs. Difference in cell self-discharge rates are often measured in the tens to hundreds of uA (with a uA being 1/1000 of a mA.) Even with a very high difference in self-discharge rate of 1mA, the 200mA balancing current is still 200 times that of the discharge rate.