During the Iraq campaign, US troops almost ran out of batteries. That would have been serious, because the most common military battery used, the BA5590, not only powers most of the tactical radios (like SINCGARS, which is found in just about every armored vehicle and every unit), but also powers the control unit for the Javelin anti-tank missile launcher and much other electronic equipment besides. The BA5590s weigh 2.3 pounds each and can power a SINCGARS two way radio for about 24 hours. These radios are typically left on all the time during combat operations. Because of their weight, most of the batteries were shipped to Kuwait aboard a ship. But then the campaign started before the supply people thought it would, with the ship still at sea, there not enough BA5590s in Kuwait to support combat operations. Each combat division was running through up to 3,000 BA5590s a day. The call went out to U.S. units world wide; air freight us your BA5590s, NOW! The factories that produced the BA5590s began to work round the clock. There was also a new replacement for the BA5590, the BA5390, which is 30 percent heavier (at three pounds), but provides 50 percent more power, and thousands of these were flown into Kuwait. The BA5590 type batteries are square, measuring 5x4.4x2.5 inches, and are going to be replaced by rechargeable models. U.S. troops in Afghanistan are using rechargeable BA5590s, which are in limited supply. The rechargeable BA5590s (and other military batteries) are very important, because a general lack of a charge indicator in military equipment means that lots of batteries with some juice left are replaced early to insure that the equipment does not need a new battery during intense combat. Rechargeable batteries eliminate most of this problem.