State-of-Charge Technology for Zn-air Battery Systems

Many missions in remote locations are currently limited by the amount of power that can be carried on foot and/or left in place for unattended equipment operation. To solve the soldier’s battery weight burden, advanced metal-air batteries are being developed. The monitoring of the effective battery power is a significant aspect for the military’s use of these batteries. One problem with the advanced metal-air chemistry is a lack of a state-of-charge (SOC) indication technology that factors several environmental influences as well as the discharge profile. The benefits from the use of SOC technology are: indication of battery capacity, effective power management, prevention of premature replacement of batteries and reduced inventory levels resulting in overall cost reduction. The major drawback from the use of SOC technology is they can be expensive especially if discarded with a used battery. Yardney proposed SOC technology provides the benefits without the drawbacks. Yardney's SOC technology proposal can be incorporated in the battery adapter cable or as a stand-alone unit eliminating the drawbacks. It will use existing technology and a custom computer chip to monitor and indicate the batteries SOC with high accuracy. It will ultimately be small in size, low in weight, inexpensive and accurate.