GEM regenerative braking

I know that GEMS supposedly have regenerative braking, but can find NO real information about it…

I know, from prior experience, that series-wound DC motors are a REAL pain to set up for regen, but understand that it’s a lot easier with the shunt-wound motors in GEMs.

Wondering though, just HOW it works: Does the motor generate power at any time the car is going downhill “on compression”, or must the brake be applied?

Assuming that this is a function of the controller, is it programmable? How much power is produced? Does anything change if the governor is set to a higher speed, or with other re-programming of the controller?

ANY info would be appreciated.

Hi solarmon, REGEN is a function of the controller, but generally it is programmable as to when it engages and how aggressive. In other words, I could reprogram my vehicle so that when I lift my foot off the accelerator, the brakes lock up and the vehicle leaves black marks and makes me spill my coffee. Or, I could set it to almost nothing to where I just coast and coast until inertia is gone and the last sip of coffee is too.

I guess your descriptive word of “compression” is the easist way to relate the occurence to an automobile. I still find myself at times going down a hill in town with my regular auto and waiting for regen to kick in. Doesn’t happen and the fuel guage doesn’t go up a darn bit.

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Aloha Tech_Support!
You mentioned in your post that you can program your controller to have regen activate rapidly or not?
I’ve read everything I can find on this forum about the correct program settings for a T1 controller and I can’t get my GEM car to have any kind of regen braking.
Do you have the T1 controller and what settings need to be changed to adjust?

@LithiumGods can explain.
Controllers have plug braking ang regen.
Iirc, motor plugs to resist over speed. That is throttle down braking.
Throttle up, down hill, is regen where motor charges battery.
T4 type controller .,also use a switch on brake pedal, to activate regen

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As the DC motors and systems go, the T1 & T2 are pretty limited in what they can do.

They have a regen setting but its not very effective. My former 02’s LB w/ T2 regen turned way up was less effective than a mere 30-40% on my '10 eL with a T4.

@Inwo is correct about the plug braking on the early ones. Its really hard on the motor and the controller. Best to disable it if you get your hands on a programing cable.

The new generation of AC drive ones are a whole different ballgame. Actially had a cell inside one of the massive old azz 6V AGMs (260Ah each ) in my eM blow up due to too much regen. And by blow up, i mean actally go boom and split. Sounded like someone shot a 32ACP while sitting next to me in the cab