Driving a 2017 Cmax Energi since November '18. It was close to new. Zero complaints other than standard...cold weather robs me of EV performance. As a retired Millwright, I'm of course inclined to tinker with shit. I've looked at the Energi battery in my Cmax and at the pics of this 2019 9 kWh and can't see an obstacle to swapping the two...other than actually buying the 2019 battery. I've been researching other batteries too, like LiFepo4 units for solar, boats and aircraft. They are super dense. If I can lay my hands on a couple, I'll post results.