[michail]

The top few percent of the battery's charge becomes harder to charge and is harder on the battery. There also needs to be battery capacity available for regeneration to dump the electricity it's creating.

That's just my guess based off of the little physics involved that I know.

E-save should kick on around 94/95% and hold there.

Also, any of the modes takes about 10 seconds or so to change from what I've seen.

 

[michail]

The big confusions/misconceptions are

1. Battery Save
2. Regeneration
3. It's just a heavy 2.0T ICE when the battery hits <1%.

 

[michail]

So just picked up a Rubicon 4xe and the Esave button does nothing. It lights up and says esave on dash but still runs in full electric mode.
Anyone else experience this and have any ideas? Checked all fuses. It also seems to have real high rpm’s when going to gas in Hybrid Mode.

The engine usually comes on with moderate to heavy acceleration and doesn't come on much when you are under 20 MPH. So it's common for it to start under heavy load like that. It's so quiet though I often don't notice over the wind/tire noise.

 

[michail]

Only thing you need e-save for is to get to a trail or camp site with 95% battery. If your wife just drives and ignores everything, the vehicle will be operating at it's optimal settings.

Wrangler4XEFan puts out some of the best videos on the 4xe and how it all works. So you have a great source on the technical info.