Regen braking with S12SN controller

LuboN

100 mW
Joined
Mar 8, 2015
Messages
46
Location
Slovakia
Does anybody know if the sinwave controllers from bmsbattery.com are regen braking capable? What mosfets are used in the S12SN model?
 
I recently purchased an s12sn with 72v lcd3. Took a look inside the controller and it contains fb4410z mosfets. It also has what it calls EABS braking with inputs for simple trigger or variable trigger (not tested). Perhaps this is what it calls regen, lcd3 parameters can adjust the motor brake strength vs regen. I've installed this on a used gt sts with a front 1500w hub motor (yes I'm crazy, you will need to build your own steel drop out if you go this route, no torque arm(s) will help you, I've tried and failed twice with a weaker 48v controller). The max output wattage of 72v controller will exceed the lcd3 display capabilities (possibly limited by exisiting code and components of both products). You may need to add an external speed sensor to the system (used reed type from existing bicycle computer on ground and signal wire, black and white) or change option in lcd3 to use motor hall. Motor hall speed sense will kick in if it doesn't receive proper input from speed sensor connection, though this does not always reset the timeout feature. Overall this was an excellent purchase as I am able to sustain 72 kph on an incline without assist. Note I am a 130lb lightweight and the bike is thermoplastic that weighs under 25lb prior to install. I may place some photos of my rig some time in the future. Good luck on your build.
 
Lancer_IV, thank You very much for the information, do You remember what settings it has from factory? I would like to use it without the lcd so I would not be able to set it through it, I have developed something like cycle analyst for myself to do the measurements. Now I am riding 14s/10Ah with Magic Pie motor at 60A and it rocks! I have other bike with MP motor and Multistar batteries (20s/16Ah) and I need controller for it. I am not afraid of replacing the mosfets and/or some other hotrodding to get more power from it :) (now I have something over 3kW max. and I would like more top speed and more power at speed). It would be really great if it could do variable regen, I was dreaming about it for a long time... Did You get any diagram/mounting info with the unit?
Wish You many happy miles!
 
I am not afraid of replacing the mosfets
If your mosfets are marked IRFB4410ZPbF (To-220 package), you can replace them with TI CSD19536KCS. This way your controller will run MUCH cooler. Please post the high resolution picture of the SMD resistor marked 122 and a sligtly bigger SMD resistor close to it (to the right of the big resistor), if you can.

Here is the "user manual": https://sklepebike.pl/userdata/gfx/cf60e906b5d29eb591cd277207ede0b7.jpg
 
I don't recall the original settings exactly, but I remember not changing the number of magnet poles (P1) which was 46 in my case and C2 phase was set to 0 for ordinary which was also not changed from my recollection. Hopefully your motor is the same configuration.

The package did not come with any instructions or diagrams. I had to work off of the s12sh diagram you can download from the site which is similar in wire colour coding but not exact in the plugs. I cut and soldered plugs from my existing controller to the new one for quick connections. There are mounting holes at either end of the controller. I placed m5 threaded rivet inserts under my frame to attach it, fairly painless operation.

The fets are indeed through hole to-220 package, I did not have the foresight to photograph the internals when I was installing my kit, sorry.

Hope it will work out for you! Attached is a couple of photos of my bike prior to the fork damage with the 48v controller. The 72v controller is the exact same size. Bike has since gone through a few changes (new rear damper, saddle, seat post, lights, new controller, repaired drop outs with half assed welding, etc.), but I'm too lazy to take it out for a photo, lol. Spring time is when I'll be adding a double kickstand and taking a new photo. Enjoy!

View attachment 1
 
Lancer_IV, thanks for photos, is there any chance You could test the controller if the E-ABS works in variable mode? I think if yes it could be done with something giving throttle like signal to the input.
 
fellow, Your mosfet suggestion is great, I even did not know such transistor existed. The only drawback is its price, but the parameters are superb.
 
LuboN said:
Lancer_IV, thanks for photos, is there any chance You could test the controller if the E-ABS works in variable mode? I think if yes it could be done with something giving throttle like signal to the input.

I won't be able to test that out right away. Possibly in spring time.
 
Do you test E-ABS ?

My test were not convincing: rear wheel lifted , if I brake, it created a jolt (à coup en français) and freewheeling ... and road test, I feel nothing :(

Does this Regen braking really works ?
 
Regen ebrake works very well on Our OpenSource firmware, I even added this mod:

Regen ebrake like coast brakes
The main idea was to implement regen ebrake, having influence from:
- the way we brake on fixed gear bikes
- the way we brake on bikes with coast brakes
- the way we drive electric cars with “one pedal driving”

How does it works?
- ebike rider can pedal forward as usual or stop pedaling for rest
- when ebike rider want to ebrake for reducing speed (without using mechanical brakes), needs to rotate backwards the pedals
- one full rotation of the pedals equals to 24 points and I implemented in a way that 5 point of backwards rotation gives the full ebrake power, while 1 point gives 1/5 of the full ebrake power and so on

More info: https://opensourceebikefirmware.bitbucket.io/development/Various--2017.12.01_-_Regen_ebrake_like_coast_brakes.html
 
Back
Top