Adding regen braking to my ebike: suggestions?

[notrafficjams]

I have a 48-volt rear-hub non-geared motored ebike assembled from a kit with 5-level PAS and a throttle.
I'd like to add a regenerative braking system (ideally a 4-level system) to my ebike.
I want a regen braking system so I won't have to ride my brakes so much while going down steep hills.
I'd appreciate any information / suggestions / referrals which would help me achieve this goal.
So far I've heard of a one-speed regen system controller made by EM3EV:
https://em3ev.com/shop/12-fet-irfb4110-infineon-sensorless-controller/
and that there is a programmable controller made by Golden Motor:
http://www.goldenmotor.bike/categories/parts-and-accessories/controllers/
Any others and and other suggestions, precautions, etc. particularly for achieving 4-level regen braking.
I am not particularly that technically minded and would have someone else install / program this for me.
I live in the San Francisco bay area.
Thanks!

 

[amberwolf]

Sounds like you want what's called analog or progressive regen, like the Phaserunner and BAC2000 controllers, and Lebowski brain can do.

There have been others, too, but I dont' remember any otehr names than those right now. Might still be some generic types available from Grin Tech, I think they called them GrinFineon?

The first two are commercially available (a search on the forum with those names will turn up sales and review threads).

But the Lebowski you'd have to build yourself (a search for Lebowski in the titles of threads will turn up a number of threads, including where to buy the brain chip and a few different PCBs to build the brain board and power boards with, and how people have set up various versions of it. I'm working on getting all the parts for a pair of them for my trike, but it's taking a while.


Keep in mind that the new controller may not operate in motor or PAS modes the same way the one you have now does.


Also keep in mind that for regen to work, your battery has to be able to safely be charged thru it's discharge port, because that's what regen does--it turns the motor into a generator, and the controller sends the generated current into the battery. If the battery is full or nearly full, regen won't work (or at least, shoudlnt' be used, because it could overcharge the battery).

There is also a risk that if the battery is very low and shuts off (disconnecting power from the system), and you then go down a hill and start regen braking, then the BMS could be overheated and damaged. There is a recent thread "Allcell battery fire" where exactly this happened.




If the battery has only one port and charging and discharging are both done thru that port, then it is safer to use regen thru it than thru the discharging port (if that's separate from the charging port), because the battery's BMS can disconnect the battery if regen would be overcharging the battery. But that will also very suddenly cease braking; if you're not prepared for that it could be a little spooky, and could also cause a voltage spike on the controller that could damage it.


There are other types of electric braking that don't charge the batteyr, but they turn the power into heat inside the motor and controller so if you have a bunch of hills then using it a lot could damage or destroy the motor and/or controller over time.




You also have to have a DD or direct drive hubmotor; a middrive or geared hub won't work, unless they have no freewheel or clutch between the road surface and the motor.

 

[notrafficjams]

This is very helpful information. Thanks so much. I'm forwarding your reply to the ebike shop which will be figuring out what to do, (if they can do anything) once they see my ebike later today.
You mentioning that my present PAS system may not work the same way with the new regen-friendly controller is a concern.
Thanks again.

 

[amberwolf]

As a side note, it is possible your existing controller is capable of regen but does not have it enabled. If you have a manual for it that explains it's options and functions, you could check--otherwise it is a guessing game as there are at least hundreds of thousands of different controller models, and even ones that look identical are not necessarily setup the same from the factory, so performing the same action that changes an option on one controller may not do so on another.