Here's my way to long description of why I love and how I use regen on my ST3 Pinion.
I live in a hilly area... so recup is very useful for me. Although most folks don't think there could be a use of recup in flat areas... as a simple substitute for squeezing the brake levers... but there is! Once I got used to using long-press on the "-" button to invoke recup, then using the + & - buttons to adjust recup up and down, I rarely squeeze the brake levers for light braking at all anymore. Whether you use the new "Cruise Control" version of recup, or the old school regular version, (more about those, below) you can always use it for braking on flat roads. Admittedly, however, recup shines the most when used in the hills.
Another less discussed advantage of recup (and this, IMHO, is the most important one) is that using regen significantly reduces disc brake pad wear. Many Stromer owners report not needing to replace pads, even after 1000's of km. Frankly, I am not in love with the Stromer brakes... I find them a bit coarse and noisy (compared to the sweet brakes I have on my Gazelle)... so using recup regularly, to slow and almost stop, has become my braking of choice.
Recup modes: Old school vs Cruise Control. The recently added Cruise Control version of recup (an unfortunate name... because it is not the same thing as cruise control in cars), is basically a way to set a speed above which the bike will be automatically slowed via recup (regen)... and below which recup will be decreased to zero. So you can nicely use it when descending a hill to keep your speed from rising too high. You may not think that would be useful... but there are times when you might normally have to reach for the brakes to keep your bike from becoming a "runaway train". With cruise control, the bike handles the speed maintenance. So, by setting the cruise speed, the bike keeps you from accelerating beyond a certain speed, but removes recup below that speed. Maybe you are descending and you know there is a turn coming up for which you will clearly need to decelerate. So you can set the cruise (recup) speed to what you want... and you bike will be controlled to roll no faster than the speed you set, until you either change the set speed or deactivate cruise control. The old school recup mode simply applies a set amount of recup force (4 levels of your choice) and it maintains a uniform amount of braking (as opposed to a set speed) until you change the level or disable recup. Some folks like that because it is a known and predictable amount of recup braking. The downside was that it might slow you more than you want and you have to spend time and mental energy changing the recup level or disabling it to achieve the amount slowing you want. The new Cruise Control version will modulate the amount of regen (through the same 4 levels of recup available in old school recup) based on how much faster than the speed you have set the bike is going. So if you are rolling at 30mph and set Cruise speed at 20mph, the bike will invoke a massive amount of recup at first and decrease the amount of recup as the bike's speed approaches the set speed. Once you reach the set speed the recup goes to zero (but will return if the bike wants to speed up). You set the Cruise speed by long-pressing (about 1 second) the minus button. This sets the cruise speed at the current speed. Then you quickly press the + or - buttons rerpeatedly to increase or decrease the set speed by a set increment (this increment is defined in your recup settings panel in OMNI. I have my increment set at 1mph. Which means each tap of a + or - button raises or lowers the cruise speed by 1 mph. The settings defaults to a 5mph increment! WAY to big a jump for me).
Unfortunately you cannot switch bewteen the two recup modes while riding. This must be done from the OMNI settings menu. From that menu you select "Recup" or "Cruise" modes. You also can set the Cruise set speed increment number. There is also a new feature that allows you to cancel recup simply by pedaling. Previously your only option to cancel recup was to long press on the minus key. Now you have an additional cancel option... by pedaling. So in settings, you can now set how much pedal force it takes to cancel recup. I have mine set to one tick above the lowest. Some folks want to be able to pedal the bike a bit before recup cancels. I assume to do some work while descending without using any battery. And I have heard some folks actually want to charge the battery by pedaling in recup mode. This would require the pedal force setting be set to very high.
How much battery recharging does recup give me? The official Stromer figure is, I think, 5-15% regen efficiency. That's a hard concept to think about. In practical terms... for me? Here's an example in my world. I have a 983kwh battery. When I descend a local hill that is approximately 2 miles long and drops about 1000 feet, I can see a 1-3% battery charge increase. So, depending on how far you get from your battery (most folks get 50-100miles on a charge, depending on riding style, assistance etc etc) that represents a potential 0.5-3 mile increase in riding range, from my example hill here. Not too shabby. Of course, remember, I used approx 5-10% of the battery to climb that hill... so that's roughly where the Stromer official 5-15% efficiency figure comes from. And remember, decreased brake wear also factors in as a 'return on investment'. And a tiny amount of carbon footprint decrease, by recharging the battery on descents!
So, in a nutshell, I use Cruise Control all the time... on the flats to do light braking and in the hills to control my speed on descents. It lightly recharges the battery, keeps my hands on the grips, saves brake pads and is just generally (geeky) fun!
