Hybrid energy behavior question GEN3 vs GEN4

If someone can elaborate this, I own a GEN3/2015 & a GEN4/2022

When driving the GEN3, paying attention to the energy monitor (the little arrows showing energy flow) I see the following behavior:

Under normal, gradual acceleration, once the ICE is running, I see energy flowing from the ICE to the tires AND energy coming from the electric motor to the tires as well (so parallel mode) while the electric motor is taking energy from the battery (I see the same with gen4) to my understanding this is normal.

BUT,

Under heavy acceleration, if I keep pushing the car, let’s say trying to merge into a freeway from an incline, I notice the electric motor begins charging the battery (arrows flowing back from the generator to the HB battery) and also supplying power to the electric motor (instead of the battery) so still parallel mode but electricity to the motor is being supplied by the generator instead of the battery that’s being charged instead. It's worth noting that this happens at any state of charge, I could have 6-7 bars on the battery or 3 with no difference, and of course the battery keeps maintaining good SOC while heavy acceleration.

I tried to see if my GEN4 does the same thing, but… even if I push it, the electricity feeding the motor is always coming from the battery during heavy acceleration instead of the generator like GEN3 does. Perhaps, GEN4 has more endurance so I haven’t pushed it enough to achieve the same behavior or maybe, GEN4 hybrid system is just programmed with this difference.

Gen3 has 88k ODO miles (I’m the second owner)
Gen4 has 5k ODO and I got it brand new.

I don’t believe my GEN3 HB battery is acting up causing this, since I get 50-70mpg easily, and the EV mode run time is pretty good, but since I didn’t get this car brand new, I don’t have a reference to tell if this is normal or not.

Does any other GEN3 owner experience this? -- thoughts?

 

Make

Make sense, and true fact that GEN4 is able to sustain longer "EV time" with the lithium battery,
as long as nothing wrong with the hybrid system I'm good, I really don't want a second car payment, hopefully another GEN3 owner can confirm and relate to same condition.
I'm not too concerned about it, and it was probably that way since I purchased it but I just noticed now. Drives really great and BlackStone oil analysis result is great.

Thank you for your feedback!

 

You are 100% correct, not all of them.
At least my 2022 Limited, the one I'm using as a reference for my GEN3 does have lithium, while the 2022 AWD does not.