Thanks all, appreciate it.
I think I found the problem. Here are the specs I found online:
CMax motor 68 kW, batteru 7.6 kWh
Soul EV motor 111 kW, battery 30 kWh
Therefore the maximum load on battery is:
CMax: 68 / 7.6 = 9C
Soul EV: 111 / 30 = 3.7C
So we have a problem here since 9C is too high. However note this would be rare, so how about normal cruising speeds on highway.
Using my Soul EV display I find the general power at average speed of 100 km/h, 55 mph is about 15 kW (summer):
CMax: 15 / 7.6 = 2C
Soul EV: 15 / 30 = 0.5C
So cruising on highway requires a moderate load from Soul battery while still fairly high load from CMax battery.
In fact I was wondering for my Engage/? display what are ticks for, 10 kW or 5 kW. I have 5 ticks so 50 kW.
At first I though that is way too high so should be 5 kW. Now I understand that electric motor is "too powerful" and indeed you can push electric motor to 50 kW based on specs. Ouch
So seems clear that Ford engineers installed electric motor that is too big in order to give us higher speeds in EV mode. This is likely selling point that Ford decided is very important. In retrospect it was a mistake. Clearly they cannot come out and say it in public. That being said we can use displays to avoid pushing battery too hard.
For myself the main rule is to never allow electric motor to go over 1 tick (10 kW) except for very short time. That would limit motor power to around 1C which should be fine long term. Also for myself using ICE gives short rest periods that help battery avoid heating up too much. Which brings us to be obvious question. How do you use battery at higher speeds while limiting electric motor to 10 kW max????
I think this car is made for P&G technique. I did a few trips this weekend and here is what I found:
Scenario 1, higher speeds:
So if you are going 110 km/h 60 mph or higher just set cruise control and forget EV mode. Use EV Later since power need is too high so ICE will do all the work. I found electric motor may assist when climbing slopes but for the most part it is idle. You will use more fuel but that is the price to pay to lack of patience ;)
Scenario 2, mid speed with more traffic, my commute to work:
The simple method is EV Later mode using Engage display to observe the EV threshold. Any time you need more power press pedal to keep power over the EV threshold:
1) pulse (to accelerate to upper speed limit)
2) climbing slopes
When you need less power release pedal to drop under EV threshold:
1) Glide (slow speed bleed while using less than 10 kW)
2) Down slope (use accumulated energy from pulse and less than 10 kW)
3) Slower traffic
This way you make ICE perform the hard work that requires more than 10 kW while electric motor takes over when you build up enough speed for nice easy coast/glide. Your average speed should still be high enough so you are not hypermiling to work. Simply select the P&G range that gives you desired average speed. For me:
1) pulse to 110 km/h
2) glide until 90 km/h
rinse and repeat
Using this method I can still get 60+ mpg
The key thing to note is that you may get home without using the full battery capacity. I often get home with 20% or 30% remaining because ICE handled a good chunk of the work and electric motor running at lower power uses less battery capacity. This is fine! In fact this is excellent for slowing down degradation since DOD is one of the most important factors of battery lifespan. So don't obsess about using full battery capacity. It will last a lot longer.
CMax vs Soul EV comparison is not fair; it is apples to oranges. I am not comparing them in general.
I am only doing that to understand battery since my Soul EV battery has had so little degradation. I am using my Soul EV as a model of a great degradation model to figure out CMax and avoid issues that long timer owners have had.
They are completely different cars for different purposes. For myself I am doing long range travels with CMax while Soul EV is great within city limits.
I am in particular interested in your thoughts on highway driving (higher speeds) and how to use battery while maintaining longer lifespan. As you pointed out the battery warranty is vague on purpose so I really want to avoid having to replace mine.