Varta Prof. Lithium 9V BLI 1 Professional 9V Lithium block. IDEAL FOR SMOKE ALARMS. Due to increasing demand for fire prevention, there will be a need for extremely long performing batteries in the future. The main reasons why VARTA Professional 9V Lithium will be the best choice for your smoke alarm: outstanding quality, a 10 years shelf life and up to 40% more performance than comparable batteries from competitors. First choice for major smoke alarms. The UL-recognized 9-volt lithium battery contains no mercury, lead or cadmium. Patented safety mechanism. Lasts up to 5 times longer than ordinary alkaline 9V batteries. 10 times longer than carbon-zinc batteries. 10-year service life up to 40% more performance than comparable batteries from competitors.