Zilla FAQ19 Feb 2007 11:38 pm

When are you going to offer a controller with regenerative braking.

As soon as I finish the Tri-Zilla, a three phase Zilla. (don’t hold your breath for that)

In my experience braking with a DC motor in a full size EV just destroys the brushes and often destroys the commutator as well. This happens either in regen or plug braking. That is why I no longer make regen controllers.
In my opinion the only real option for DC systems over 108V at this time is adding a generator/alternator on the end of the motor.

-Otmar

5 Responses to “When are you going to offer a controller with regenerative braking.”

  1. on 22 Aug 2007 at 3:59 pm   Rod Smith

    Are you aware of any vehicles that have implemented this configuration? If so, could you provide contact information or a website I could use for reference?

  2. on 21 Jan 2008 at 8:54 pm   Otmar

    This reply is very late since comments have been getting lost in spam for many months. I’m sorry about that. I think I dug all the real comments out of the pile.

    Solar Car Corp of Florida installed many of these systems before they went out of business in the 1990’s. There is a image of the system with specifications on the EValbum. You can find it here:
    http://evalbum.com/tech/regen.jpg

    Judging by how few people do this anymore, it’s probably more work than most people want to do after finishing the conversion.

  3. on 20 Jul 2008 at 3:53 pm   Bob Sisson

    Don’t the new generation hybrids use a Regen system? My question is how do they determine when to regen and when to brake? If the Regen fails, then you may be too late when braking, too much regen and the anti-lock kicks in…

    In thinking about Regen in a small project car, you can do SOME regen based on backing off the throttle, but once you touch the brake pedal, you need to be in full mechanical brake simply for safety. Mechanical brakes just don’t fail, maybe the vacuum pump dies, but the brakes still work as they are purely mechanical.

  4. on 27 Dec 2011 at 2:39 pm   Joe

    Any progress on Tri-Zilla?

  5. on 28 Dec 2011 at 12:25 pm   Otmar

    Nothing substantial is happening on the 3 phase front at this time.
    RMS is offering AC drives today of moderate power, but also with the usual inherent higher cost per Watt. Until I can bring the cost down substantially I’m thinking of staying in the sweet spot of power and performance offered by the DC drives.

    I have been seriously considering reviewing DC regen since I have learned quite a bit since the last time I did that in the 1990’s. There’s a unusual trick or two that I’d like to try out on the Zilla. Who knows? I may have to take back my words in the above post.

    Also to Bob,
    Integrating regen and regular braking is not a simple thing, especially when anti lock systems are included. Most hybrids use the first part of brake pedal travel to control regen before the hydraulic brakes come on and then cut out all regen as soon as any traction control sets in. I think that is a reasonable option for those without a engineering department to spend much time on it.