What determines how fast kers charges?

In this mornings race the guy directly in front of me had his kers charge approx 25 seconds before mine. I've seen like 5-10 seconds difference before but 20+ ? We started close on the grid aswell.

So what actually determines the speed it charges at?

Edit: For reference the 25 seconds is a guess. His kers charged at the hairpin on Suzuka. Mine didn't charge until the very last chicane.

Edit2: Just timed it. It's actually more than 30 seconds difference.

Push level is 1 of the reasons, the higher the push level the quicker it charges.

Also seen differences when your drivers have totally different setups due to being at a different stage of training, weather its the training or the setup i dont know but i'd guess at car setup.

Well he was on softs and I was on hards, so I was pushing harder than him for much longer. Hmm..

His driver is less trained than mine too. Mine have max attack/speed/phys/defending, his dont have max anything.

I might be wrong there, was just an observation, my guys used always be last to charge and it seemed i was the 1 looking after tyres most so put two & two together but that was long long time ago tho.

i definitly think car setup's got something to do with it tho

Yeah when i had 2 different trained drivers (1 fully trained & 1 rookie) the one with the lowest training and more wing and shorter gears probably different brake bias aswell etc alwarys charged 1st.

KERS charges in braking zones so it doesn't matter how much longer it took you in seconds, what does matter is that there was not much braking done between the hairpin and the last chicane. That's all I have on this topic, no idea what determines it exactly xD

Im not sure about this but I think brake balance in setup can affect this. Made an observation when i changed driver and his brake balance was different and kers took longer to charge!! But as i said, i might be wrong!!

In a race like Monza KERS takes 7 or 8 lap to charge while it would take usually around 5 lap (except Monaco, Budapest?).
Cornering and braking zones are what's matter regarding how KERS charges?
Push level might have an influence too...