Lithium Ion Cell Balancing

Only cells from better manufacturers are closely matched and batteries that use them require very little balancing.

Lithium ion cell balancing.

In this arena lithium ion battery technology is fast becoming the standard. As we know lithium cells are very sensitive to overcharging and over discharging. Safety hazards from overcharged cells li ion batteries have very high electric energy concentrated in small volume. Active cell balancing it uses capacitive or inductive charge carrying to move charge between battery cells.

How do you balance a lithium ion battery. Balancing takes care only of the 1st one. Unfortunately cells from many manufacturers have significant cell to cell variations. Active cell balancing is an amazing way to handle the cell balancing problem but in terms of system integration and optimization this approach takes a hit on many fronts like cost and complexity.

Figure 1 illustrates a five cell balancing circuit with 1 ω resistors setting the transfer ratio which is the ratio of the imbalance voltage v cell v avg to the balancing current i cell. Quality li ion cells have uniform capacity and low self discharge when new. It is significant progressively productive in light of the fact that energy is moved to the necessary spot. Since it is bidirectional charge from any selected cell can be transferred at high efficiency to or from 12 or more adjacent cells.

The means used to perform cell balancing typically include by. In a pack of four cells if one cell is 3 5v while the other are 3 2v the charge will charging all the cells together since they are in series and it will charge the 3 5v cell to more than recommended voltage since the other batteries are still require charging. Consumer electronics are basically built for them the combination of low weight to energy and a relatively slow loss of charge making them ideal for portable devices. Equalizing the socs of the various cells in a battery.

With improved battery cells and new cell chemistry the battery variation is stabilizing. The improved effectiveness is the requirement for extra parts at a greater expense. A problem arises when a cell in a string loses capacity or develops elevated self discharge. True balancing brings the battery into perfect balance on every charge cycle.

The worst thing that can happen is thermal runaway. Lithium ion batteries will never be out of balance again true balancing is a completely new approach to cell balancing. Different algorithms of cell balancing are often discussed when multiple serial cells are used in a battery pack for particular device. The lithium ion battery balancing act more and more the world is running on lithium ion batteries.