Situation normal with the Web stirring up a bunch of mass hysteria and FUD (fear uncertainty and doubt)...
Common sense here please: Folks installing charging stations should be including a hard-wired high grade surge suppressor when the units are put in place. Reality check: With a charging station and car combination you are directly connecting over $30,000 worth of electrical equipment to the grid. How many folks have surge protection on their computers and TVs?
I have used a GE Wattstation to charge my Nissan Leaf every day (sometimes three times a day) for the last six months. In fact, that is the only charger that has been used with the car, except for its first charge at the Nissan dealership.
As others have mentioned in other posts on this forum, there have been plenty of other diode failures on other chargers, but the common thread seems to be electrical interruptions, breakers being opened / popped, etc. A few months back here in the Nissan Leaf forums folks commented back to me on this that a surge protector is not going to save you in a direct lightining strike. Well folks, we are not talking about direct strikes here, the idea is to protect against surges...
If you have an EVSE, you really should have surge protection as close to the charger as possible – it is just simple common sense.
One other commenter here mentioned the state of charge percent and the Wattstation. The state of charge is controlled by the Nissan Leaf, not the EVSE. The EVSE/charger just connects the car to the power source – it only connects or disconnects when the Leaf says to.
Disclaimer: I don't work for GE and don't own GE stock. I do live in a small town with a GE plant that makes circuit breaker panels that is likely being closed next year according to the local paper.