From 2010 to 2016, battery pack prices fell roughly 80% from ~$1,000/kWh to ~$227/kWh
From 2013 to 2017, ranges of EVs have increased. The Nissan Leaf went from 75mi to 107mi, and the Tesla Model S went from 208mi to 249mi. This is mostly due to bigger battery packs (24kWh --> 30kWh and 60kWh --> 75kWh respectively).
In 2016, the battery pack cost is still ~$227/kWh, meaning that a 60kWh Tesla battery pack is ~$13600. The target cost for parity with ICE vehicles is $100/kWh, which is likely to happen sometime between 2025 and 2030.