Regen with Lyen12FET and CAV3-DP

[liamcaff]

Hey all,

So I'm nearing the very end of my build. At the moment I'm trying to get Regen to activate with the 12FET Lyen Extreme Modder Controller. I have the controller version with the external JST connection for regen activation - so this connection is made. I also double checked this connection by opening up the controller and the wire are indeed connected to the correct place (BK and GRND). All that happens when I pull the bake is the motor cuts out with no regen braking whatsoever.

My battery is 82V LIPO (20s2p) 10AH.

Right now my PC seems to have given up the ghost - currently try to sort that out. But in the mean time these are my 12FET settings:


Is my Regen Voltage too low at 55V? I have 2 torque arms installed but am just being cautious about messing around with Regen having read quite a few forums posts on the topic here...

Any thoughts?

Cheers

 

[bowlofsalad]

I am pretty sure the voltage of your pack must be below 55v before it is allowed to activate with 'regen voltage' setting at 55v. So, for example, say you are using a pack that comes out at 60v hot off the pack and all the cells are very close to their maximum voltage that you don't end up over charging when you activate regenerative braking.

I just checked my version of this program and the highest I was able to set this to (for some reason I don't know) was 75. Maybe your version has a higher setting.

In addition, you might also try to have the plugs that have to do with allowing regen separated and together.

I am not sure if these are your settings, and if you use a 3 speed switch, but if you do, you should change the speed 1 speed 2 and speed 3 setting. I love using the 3 speed switch.

Another thing that tripped me up was the 'default speed', this means that if the three speed switch is disconnected it will default to whichever speed setting you have selected. Which you choose is your choice and all have relative virtue, but it's good to be aware of this setting.

 

[liamcaff]

Thanks for the reply salad

I understand the danger of over charging the pack, that's why I'm cautious about changing my settings... Any idea what a safe value might be for the Regen Voltage when my battery pack is fully charged to 82V?

Once I get Regen working I'm going to look at the 3-speed switch. From what I've read it would be best for me to plug the 3-speed switch directly into the controller and not use the Cycle Analyst Aux Input... Will look at this in more detail after braking is sorted.

Will try disconnecting the external Regen connector too but am pretty sure this should be connected to enable regen.

 

[bowlofsalad]

Thanks for the reply salad

I understand the danger of over charging the pack, that's why I'm cautious about changing my settings... Any idea what a safe value might be for the Regen Voltage when my battery pack is fully charged to 82V?

Once I get Regen working I'm going to look at the 3-speed switch. From what I've read it would be best for me to plug the 3-speed switch directly into the controller and not use the Cycle Analyst Aux Input... Will look at this in more detail after braking is sorted.

Will try disconnecting the external Regen connector too but am pretty sure this should be connected to enable regen.

Are you able to set the voltage to whatever you want?

I have never used a LIPO pack before so I probably couldn't say with a lot of confidence, but after looking up some 'lipo voltage curve' charts, I might guess 78v-80v. It'd probably be wise to know for sure what is safe though.

 

[liamcaff]

Yeah I can set the value for the Regen Voltage to whatever I want...

Will keep reading before I play around with the values and get a calliper for the rear disc brake installed in the morning.

 

[liamcaff]

Rear disc brake installed...

Still no regen though.... Anyone any ideas? I havn't changed my controller settings yet...

 

[t_tberg]

Lyen controllers have a max regen of 75v, to get around that you have to add a resistor to the regen circuit in the controller and then proportionally change the regen voltage and LVC in the program. When I asked Ed about 20s specifically he gave me this info : "The regen voltage should be near or below the charger voltage. So for 20S lipo, the regen voltage should be around 84V. the controller program only allows up to 75V regen. To go higher than that, the resistance on the regen related resistor need to be modified. The resistor is marked as R12 on the circuit board. The suggest resistor to add in parallel with the existing one is 3.6Kohm. Once added, the low voltage cutoff formula for your voltage controller will be off-shifted. Program LVC = real (LVC + 2) x 0.75. For example, real LVC for 20S lipo is 56 (20 x 2.8, then program LVC = (56.2+2)x 0.75 = 43.5. The maximum program regen voltage formula is (real regen x 0.75), 84V x 0.75 = 63V, so 60V in the program would be the closest choice."

 

[t_tberg]

Why am I responding to a two year old post?

 

[Htfan]

Why am I responding to a two year old post?

Because you have good intentions... 8)

 

[t_tberg]

Thanks Htfan, I think most of this community shares an alrtuistic outlook. I try to share what I know when appropriate because others on this forum have helped me

 

[liamcaff]

And the question is still relevant!

Thanks for the info!!