09 DS Alltrax/Admiral/Lithium no power on hills?

[superfan86]

I've got an 09 DS with a new Eco 105 lithium pack, Alltrax 500, and an Admiral A4 (torque). New MCOR, 200 amp solenoid, and 0 gauge wires all around. It rides on 23" tires.

I'm an experienced cart guy and have been through different brands and configurations over the years, so I built this with input from Scottie and Dave to try and find the "perfect family cart." Top speed is about 25 mph and it will pull the front wheels off the ground when floored from a stop and climbs curbs without a sweat. Ridding 4 passengers with no reduction in top speed no problem and our range is fantastic.

My only concern is that I sometimes don't feel like the cart is really putting down the torque that it is capable of at cruising speed. We live in a pretty flat area, but we have some mild but longer hills. When we hit these I can feel the cart slowing down as we go along and the amp draw seems to cap out around 100 with the pedal on the floor.

My Alltrax settings look good. Have I just found the 1 limit in my setup or is their something I can do to allow my motor more amps in this situation?

Now that I write it down I think I'll swap in the Torque field map and see what happens, but I'd love to keep the speed map if possible.

[Volt_Ampere]

Torque map may give you lower speed. Your performance sounds normal to me. Cart will have reduced max speed going up hills. Max current only will be seen under hard acceleration from lower speed. The motor BEMF is limiting the current at higher speed.

[scottyb]

Try the torque map with the bigger tires. Set the Battery maximum amp draw (MAD) to 300. Set the armature MAD to 500. Be sure turbo is on. Set Max RPM to 6200. The 500 amp controller requires a 400 solenoid. Don't know if that is holding you back but Alltrax requires a 400 solenoid for the 500 controller.
Let us know how these changes effect the performance.

[superfan86]

Originally Posted by scottyb

Try the torque map with the bigger tires. Set the Battery maximum amp draw (MAD) to 300. Set the armature MAD to 500. Be sure turbo is on. Set Max RPM to 6200. The 500 amp controller requires a 400 solenoid. Don't know if that is holding you back but Alltrax requires a 400 solenoid for the 500 controller.
Let us know how these changes effect the performance.

Thanks. I got it from you, so it must be the 400. GIANT orange thing.

I'll check those settings. I'm not complaining. I just want to verify!

[superfan86]

Originally Posted by Volt_Ampere

Torque map may give you lower speed. Your performance sounds normal to me. Cart will have reduced max speed going up hills. Max current only will be seen under hard acceleration from lower speed. The motor BEMF is limiting the current at higher speed.

Thanks. Between the 2 maps I think I saw maybe a 1-2 mph drop in speed, but left the speed map on because the torque map was getting wheelie happy to the point it was slightly unsafe.

What you are describing matches my experience, so I'm prob ok. The speed drop on the incline is not a problem, just of note, so if the motor has a mechanism that limits draw in that situation then that's what is happening.

[Volt_Ampere]

All DC motors will self limit the current at speed. The Field Map can help get more speed by weakening the field at speed. On level ground, my cart pulls about 70 amps at full throttle full speed. Doesn't matter what max amps I set the controller to. The max amps only comes into play on hard acceleration at low speed or on very steep inclines.

[superfan86]

Originally Posted by Volt_Ampere

All DC motors will self limit the current at speed. The Field Map can help get more speed by weakening the field at speed. On level ground, my cart pulls about 70 amps at full throttle full speed. Doesn't matter what max amps I set the controller to. The max amps only comes into play on hard acceleration at low speed or on very steep inclines.

That's what I see too. Cruising speed draws about 60 amps and performance is as expected.

The missing piece for me was that motors are smart. I just assumed the controller dumps amps into them till something in the controller said otherwise.

Love the knowledge on this forum. Always cool to learn more.

[Volt_Ampere]

Motors are not smart. They limit current because of the way they work. No electronics - just magnets and coils.