Batteries have improved significantly since 2008, and are still improving. The most important shifts have been in cost ($/kWh), but there have also been improv

Batteries have improved significantly since 2008, and are still improving. The most important shifts have been in cost ($/kWh), but there have also been improvements in energy density (Wh/kg), power density (W/kg), and cycle life. Some of this is due to electronics improvements, but a lot is due to better cell design and manufacturing, funded in part by higher demand.