As its car sales stall, Tesla (TSLA) is expanding its growing energy storage business. At an event in Nevada Monday night, Tesla announced two new products, a Megapack 3 battery pack and a Megablock ...

More and more, big arrays of lithium-ion batteries are being hooked up to electrical grids around the U.S. to store power that can be discharged in times of high demand. But as more energy storage is ...