MP3 RegenBraking working not as before

[Sam.Vanratt]

Hi
I changed my electronic after a complete failure of it. I programmed it (see attached pic) and everything works as before, but the Regen Braking is nearly not there (maybe a fifth of the 80% I had before).
What am I configuring wrong?

Cheers
Sam

[Bikemad]

Hi Sam,

Try setting the regen at 116% to see if it makes a noticeable difference.

If you are not using a 24V battery, it might be worth setting the battery voltage to match the battery being used, as the replacement controller could be of a more recent design which may not work exactly the same as the original MPIII controller.

The regenerative braking force on my MPIII is very noticeable at very slow speeds, whereas the regen on my MP4 will only engage when I'm going faster than ~6.5 mph and also cuts out completely below 3 mph.
I really prefer the regen on my MPIII because it can be engaged at any speed and will then stay engaged until you release the brakes.

If I freewheel slowly down a long hill with the MP4 and then hold the brake lever in just far enough to activate the regen but without applying the mechanical brakes, the bike will slow to about 3 mph, whereupon the electromagnetic dynamic braking force simply stops altogether, allowing the bike to quickly speed up again until it reaches ~6.5 mph which then allows the braking force to automatically cut in again.
This very annoying sequence of braking and accelerating will continue indefinitely all the way down the hill until the brake lever is either fully released to exceed 6.5 mph or pulled harder to apply enough mechanical braking force to prevent it from reaching 6.5 mph.

Alan
 

[Sam.Vanratt]

Hello Alan
the 24V (25,6V pack) are actually what I'm using (with 28" tires it gives exact 25,6km/h which is allowed here). I'll try the 116% and see if there's a change. As I tried 80% and 100% already I doubt it. As I have a second (wife) MP3 equipped bike with the 80% I feel the difference very easily. With the current controller the Regen is more like not there at all (at high speeds, at lower it reacts better, below 10km/h it doesn't feel braking at all). Not comparable to the controller before. As I took the same settings I wondered what happened, or what could be wrong....
I'll report back tomorrow with the new 116% settings
Cheers

[Sam.Vanratt]

Hello Alan (and the rest of the GM community)
today I took some time &effort for testing and measurement. I always accelerated to max Speed (~25km/h) and then use the Regen brakes (which are autarkic from the two other brakes) to slow down and took a crude measurement how long it took.
At 50% I didn't feel any difference and it took about 50m to come to a halt. As the motor stopped humming the (two 1+4 brakes are out of question)
At 60% it was the same and it didn't matter if I brake or just let no accelerate
At 80% it started at a very low rate (with the other MP3 bike 80% was already very strong deccelerating) and it took about 40m to stop. This was the setting before I changed the controller.
At 100% it took 28m to stop.
At 116% there's a difference and it took 15m

With the other Mp3 bike (about 10kg lighter than this one) it takes (80% Regen) 9m to a full stop.

What's wrong?
Cheers
Sam

[Sam.Vanratt]

Hi
today my Regen is nearly gone. As long as I'm above 15km/h you could feel a slight brake (maybe half of what is 'usual' with 116% setting (which is maybe half of what I used to be with 80% with my old controller), under it seems not existing and under 10km/h it's no difference if I brake or not. A small bridge with 8m heights and 60m slope is not capable with Regen braking alone. The motor stops instantly accelerating so the brakes are OK. I checked the controller settings which are the same. At the same moment the brake stopped working the PAS is "disabled" as well, as I'd accelerate without pedaling.

Is there a way to look into the controller logs? Is there a way to update the firmware?
Cheers
Sam

[Bikemad]

Hi Sam,

Unfortunately you can only access the programmable parameters, and I don't suppose that the controller actually logs any information at all.
You would not be able to alter the firmware without the factory programming hardware and programming code that GM use, which is unlikely to be made available for end user use.

I would suggest that you disconnect (unplug) each brake lever in turn and see if one brake has a different effect on the regen to the other.
It probably won't be any different, but it is worth checking anyway just in case you have a problem similar to the brake switch fault that Ron experienced.

If your battery packs are the same on both bikes, it might be worth swapping them over to see if it makes any difference (just in case the poor regenerative braking is being caused by the battery's BMS unit).

Alan
 

[Sam.Vanratt]

Hi Alan
that's what I checked first. As both brake switches were defective after about one year (sometimes reaction was nullified) I switched them as explained in the Thread about the "MP5 and Regen not working" with a better digi dual switch (with a so called buckling spring switch). As my brakes (hydraulic) are not connected to the two Regen-only brakes it's easy to test (so I have four brakes grab). As the Regen settings are already far beyond the value which it should be (116% felt like 40% in my wives Bike, and now the brake is at max 20% of what's normal; under 10km I don't see any reflow (Current). As my Battery Pack (a 10kg pack with 24V/40Ah with Supercaps as Regen drain) it's completly computer controlled and I see + log any doing Current flow, Li Volt, sinlge Cell status + SuperCap voltage+current) there; a fault there is impossible without notice. The not more working PAS is another subject.
So as the controller seems quite in the middle of it. When I wrote to devi motion about the controller they offered me to sent the complete wheel to them for a complete checkup (I tested the HALL sensors before using the new one just to avoid another opening). Unluckily a 12kg package at that size to them is about 90EUR which is more than a new controller. Just switching the controller will get me 17EUR postal costs, but bring me the 70EUR for the controller back, BUT I need a replacement. A working one and as I changed such controllers now 3 times, I'll step over to an external one, instead of debugging faulty controllers again. Disassembling my front wheel is really no fun or fast done.
Cheers
Sam

[Sam.Vanratt]

Ordering a new MP III one will cost me the same as four weeks ago, so 85EUR. I've never looked into different (sensor) controller so I'd need advise which one works best as alternative. Three years ago I collected and published the pro/contra of the MP III and it's failures. Seems not so much changed in the GM design rules and the old HALL sensor problem seems still the same as the time I've decided to go with GM despite it's quality problems.
That was the old thread:  http://goldenmotor.com/SMF/index.php?topic=5092.0
What was the best solution for the MP2 apart from the PD282 (or so it was called)? How was/is the cable solution out of the Hub?

Cheers from a worried
Sam