Battery recharge cycle sucks...

From the Gen3 BSFC (brake specific fuel consumption) charts published when this series was rolled out, I thought this engine was already quite close to top efficiency at that lower RPM, certainly better than on the Gen2. High efficiency is spread over a particularly wide RPM range.

2500 RPM is too high for just simple battery charging, because that point on the ECU-managed engine operating curve is more power than the battery can accept.

 

Because the best efficiency is achieved at power outputs way higher than the battery can be charged at, so it is useless to be in that range just for charging the battery. Charging while being stationary is inefficient and should be avoided. That's also why it won't charge to 60% SOC while stationary.

 

It does regen charge over 60% when warming up from cold soak or if ecu detects that engine temp is below threshold temp