Charging at the top of a hill

Ok thanks. It sounds like it's a more gradual hill. I think we're learning that it is possible to charge the battery beyond 100% via small to moderate rates of regeneration. But if the rate of regen gets too high, the car kicks on the ICE and diverts some of the regen energy there. You can see it nearly happening in the graphs in my post #26 in this thread. On my hill the steepest bit is right near the bottom, and there is a stop sign right afterwards. When the ICE kicks on, it always happens either in that steep spot or as I stop for the sign.

I actually had the ICE kick on yesterday, coming down a different hill, when my battery was less than 10% charged. I had it in B mode to maximize the regeneration and in a steep part the engine kicked on. As a side note, I have been noticing lately that I can get more % regen from a hill in B than in D. On my dirt road, for example, I can get 5% in B, but only 3% in D.

Another bit of anecdotal evidence, I once was stuck at 100% battery for over 5 miles of purely EV driving. I was really getting worried that something was wrong by the time the battery % meter finally started dropping. I think what happened is that it got overcharged coming down my hill, then kicked on the ICE at the bottom, and continued to overcharge even further anytime I let off the gas going downhill over the course of the next 10 miles, but used gas for any uphill bits. By the time the engine finished its warmup cycle and turned off, the battery was probably 105% at least. It was also an unusually warm and sunny day, so it's possible the computer was making some adjustment to its range calculation, although the miles of EV left display wasn't changing either (was stuck at 25.4 miles or something like that).