This is not a plug-in hybrid is it? Non plug-ins only charge when the ICE is running or by regenerative braking. They hardly ever charge to 100%, usually around 50%.
<grin> Yes, they do! I can regularly get the HVB to 100% - especially in Winter. My problem is that with the cold, the HVB rarely gets below 50% before the ICE kicks in and spoils things. It's only in low-speed city driving I have a shot at getting a low charge on HVB.
TBH, I think it's the driving conditions that allow the HVB to charge up like that. I'd still be somewhat concerned if I could NEVER get the HVB much higher than 50%.