Feb 7 (Reuters) - Hundreds of used electric vehicle battery packs are enjoying a second life at a California facility connected to the state's power grid, according to a company pioneering technology it says will dramatically lower the cost of storing carbon-free energy. It is also a more cost-effective way to deploy the massive amounts of battery capacity needed to store solar and wind energy for when the sun is not shining or the wind is not blowing. See here for a complete list of exchanges and delays