[gahabana]

Thanks for sharing @hkl00k ... this is super informative !!! and it confirms some guesses i had.
I don't know why it stops at 75% but have a guess further below.

My 'feelling' (and little bit of thinking) without knowing really how things work - petrol engine is 220-230kW (i.e. 300+ Horse Powers) .... Charger from AC takes maximum 3.7kW ... if i assume some losses converting mechanical power from ICE it would take probably about 7-8kW (50% efficiency from ICA and however charging works) which is about 10 horse powers. So when driving 115km/h i have no clue how much PS is needed but my guess 100-ish so these 10 HP for charging at best should require engine to produce 10PS more ... which should not yield dramatically higher fuel consumption

Now, i am more curious in how many km you had to make - 300km for 75% capacity i.e. 13kWh ? thats maybe 3-4 hours driving (assuming average speed of 100) ... close to 4kw/h ? that sounds about right close to the max speed of AC charging via cable (3.7kw/h) ... ?

In other words takes 3-4 hours of driving with 'charge' mode on ICA to get to 75% ... now my 'opinion' is that it does not charge beyond 75% because it can not handle 'trickle-charging' - batteries do not respond well when close to 80% with high speed charge but prefer to be charged with lower and constant current. Maybe that can not be done well with ICA. That is again just a guess.