Regenerative braking

[Pw2000]

I currently have a voiliamart 1500w EBike 48v 13ah battery. I have original voiliamart 1500w controller.

I want to add regenerative braking.

I want to add a switch to the bike to activate regeneration braking.

Voiliamart says there controller does not have RB
Do I need a new controller and LCD display ?

Please advise the best route.

I would like to regenerate on high power as I will only activate when voltage is below.

Thanks for your help.

 

[AHicks]

It IS about the controller and display, working within it's capabilities. The ONLY reason I can think of to add regen is if you are riding in an area with some big hills and looking for some help holding your speed in check to come down them. If you are thinking that regen is going to add some battery charging of any consquence, I think you're going to be badly disappointed.

Regen is normally energized when the brakes are applied, using the same switch that kills the power to the motor. You can set the adjustment so the engine kill function is engaged slightly before the brake pucks actually touch the rotor.

A lot of the KT controllers are set up for regen, but make SURE it's listed in the controllers features as not all are capable.

 

[tomjasz]

Regen is more valuable to me as a source of increased braking with my front DD motor with rear coaster brakes. Expecting a voltage boost will be disappointing. IME.

 

[Pw2000]

Thanks for the replys.

 

[kmccune]

Regen is more valuable to me as a source of increased braking with my front DD motor with rear coaster brakes. Expecting a voltage boost will be disappointing. IME.

I love regen for that reason only, no expectation of increased range- back in the day I hated driving a truck without an engine brake,I could make a set of brakes last way over 200K miles on my backdump in hilly country, other Guys would burn their brakes out around 50K miles.

 

[AHicks]

Yup! Regen = engine brake

 

[kmccune]

Yup! Regen = engine brake

In Europe they used to have a small generator thingy that was coupled to the rear wheels to retard the motion going down Hills and inclines, of course it would even work on a petrol-powered truck. Diesel-electric trains use the electric drive motors to keep the speed down and prevent a "runaway" on long grades, the energy recovered is dissipated in a "resistor Bar"They tell me these things can get red hot.

 

[tomjasz]

They tell me these things can get red hot.

I've not seen any heat issues with my 1000W DD Hub motor.

 

[AHicks]

I've not seen any heat issues with my 1000W DD Hub motor.

The regen I've seen on direct drives is adjustable for how much braking you want. That's assuming you even have regen, AND the BMS is accepting more charge.

It's going to take a big hill, and a lot of regen to get hot....

 

[kmccune]

The regen I've seen on direct drives is adjustable for how much braking you want. That's assuming you even have regen, AND the BMS is accepting more charge.

It's going to take a big hill, and a lot of regen to get hot....

Actually I was referring to a Dash 8 or similar locomotive, a string of 100 "Cars" is going to have a lot of push, I know this is about ebikes, the regen thing was for example, the principle is the same any retarder is going to generate heat as well as electricity or in the case of most Diesels, compressed air released explosively.( the exhaust brakes merely make it harder to exhaust the compressed air{flow restriction- can consume a fair amount of power}.
All romanticism aside all "Otto Cycle engines are mere "air pumps".

 

[Pw2000]

Hi does anyone know how I can make my voiliamart 1500w controller so it activates regeneration? I have read soldering abs to ground does the trick.

I have no idea how to do this. Please would someone explain?

Its more for voltage sag than range I wanted rege.

My 1500w ebike when it's fresh off the charger is very fast it is a 48v tigershark battery. But after a 3 miles or so the top speed comes down from 40mph to 35mph.

There's alot of hills on my commute that I could collect power on. I have heard conflicting opinions of regeneration and is it worth it or not. I would like to give it s try as it appeals to me.

Thanks for your views and help

Paul

 

[tomjasz]

40mph

A difficult speed to maintain unless you run a 60v battery. Maintaining those speeds, the 40mph wall, is difficult. Not all controllers are capable. Get a better controller like the multirange Grin controllers with some programmability.

48v tigershark battery

You don't discuss battery specifications. Some cell configurations with limited parallel cells will sag. Regen isn't a solution.

 

[kmccune]

Wow, that bike is crazy fast,I got up to 36 mph after I went to an 11 tooth freewheel and it scared Me, Whitetail Deer are a thing around here, I imagined after a Deer collision the Deer would walk away while I lay there in a crumpled heap, you have 4 times the kinetic energy to dissipate during a 40 mph crash vs 20 mph.
Try a 52 volt battery if you want that much speed, you may be better served with an EMotorbike if you want those speeds, the Human body is not really crashworthy, especially for us older guys.

 

[tomjasz]

crazy fast

Goofy fast. And likely poor braking distances as those speeds. Ben there, done that, but chose to hang around at least another decade.

 

[PedalUma]

I have heard stories of people who live on a hill in SF leaving their door in the morning will a full charge and then using regen as they go down the hill. The overhead of these systems does not seem worth the miniscule payoff. If I understand, it cannot work with lighter weight, more efficient geared hub motors and clearly not with mid-drives with cassettes. People ask me daily if my bike charges as I ride it. I need to diplomatically explain that it is like a rechargeable drill that does not charge as you drill.

 

[Johnny]

I have heard stories of people who live on a hill in SF leaving their door in the morning will a full charge and then using regen as they go down the hill. The overhead of these systems does not seem worth the miniscule payoff. If I understand, it cannot work with lighter weight, more efficient geared hub motors and clearly not with mid-drives with cassettes. People ask me daily if my bike charges as I ride it. I need to diplomatically explain that it is like a rechargeable drill that does not charge as you drill.

You shouldn't dismiss this feature. There are some big positives. Recouping is one, braking is another. Actually regen braking downhill is amazing. Instead of generating heat and wearing out brakes it recharges my battery.

Mid drives can not do it. Geared hubs can be designed do have it, grin has one such design.

 

[kmccune]

Goofy fast. And likely poor braking distances as those speeds. Ben there, done that, but chose to hang around at least another decade.

Yes, after a while sense and sensibility beckon.