openinverter forum

Just wondered how people were using regen.

I have mine set to only come in with brake pedal as regen on coast seems less efficient than simply lifting off earlier, and also it makes changing gear harder if there is load on the gears.

So at the moment i have a set regen and it works ok, but ideally it would regen more the harder i press the brakes. The problem is currently the brakes start coming on near the top of the brake travel, so regen is sharing deceleration with the brakes, and i know which i'd rather have.

Have people adjusted their brakes to come on later and say used the top quarter of travel to vary the regen. I couldn't use hydraulic pressure for this as there wouldn't be any until the brake start binding but i could fit another sensor to work at the top of the pedal travel, and then i think i could vary the regen over CAN based upon travel ?

the ideal would be too drive sensibly and avoid using the brake pads at all. On a descent i think regen could be significant if you slow the descent on regen only

or is this overthinking it ?

In all conversions I've done it as variable as possible.
I like one-pedal driving but by the press of a button I can turn off off-pedal regen completely or adjust in various steps. In Polo I had a simple pot to adjust off-pedal regen from 0-100%. In Audi I overloaded the direction buttons, once at a certain speed they will adjust regen in 4 steps, down to no regen.

Brake pressure in Audi and Touran is quite sensitive, so I can use the first say 20% to set regen to its full strength (currently 60 kW). In Polo I had just used the brake light switch but of course that is not quite as smooth.

I run about 15% off throttle regen and 60% under braking any higher and I start locking the rear wheels! I find this a good balance and very drivable, coasting is still totally possible you learn very quickly where that part of the throttle travel is

At first i used regen from both sides.
1. When brake pedal is pressed it would signal regen. This can be set from the interface.
2.I tried with simple linear brake pot too. I liked this better than brake switch. I would be able to vary brake pot and get a good linear effect.
I also tried variable 5K pot from Colvern mounted on the brake pedal. It would open from 5% brake pedal travel up to 30%. It was good for about a year and later developed a zone where it would not have effect.
3. Off throttle regen. When foot is at throttle there is a 20% throttle travel where you can vary regen torque as a single pedal effect. This too can be set within OI interface

Now i dont like brake regen anymore because i consider it dangerous in winter and slippery road. Also stopping at the crossroads tu turn right can block your wheels even before brakes are fully engaged. Also shifting can be difficult if you need to shift and brake at the same time...
I belive brakes should have mechanical only effect, besides if you release throttle you get full off-throttle regen anyway. No additional effect necessary.
Of course you need to connect a regen disable switch so that you can remove regen if in winter conditions.

There is additional reason for that switch. When at MOT inspection you need to remove regen otherwise they cant test the brakes propperly.

Mot brake testing should be done in neutral..

Ev8 wrote: ↑Fri Jun 23, 2023 8:22 am Mot brake testing should be done in neutral..

Yes but some testers forget to put transmission in neutral . I just disable regen beforehand, safer that way.