Individual cell voltage equalizers (ICE) for reliable battery performance

The individual cell voltage equalizer (ICE) is a two-terminal voltage-controlled current shunt. The ICE unit is connected to the positive and negative terminals of each cell in a battery string. ICE provides each cell with an alternate current path for string float current. Using ICE makes it possible to check battery cells by using a simple digital voltmeter, when cell voltages deviate by more than ±0.05 V per cell and capacity testing or replacement is required. ICE was designed to monitor and control individual cells in stationary battery strings. ICE monitors cell voltages and acts as current shunt by allowing current to bypass cells with high voltages. Conversely, current will pass through low voltage cells to bring voltage back to the current level. ICE was designed with limited shunting ability. Thus, weak cells are identified before failure. The result is timely and orderly cell replacement