Pds ezgo with new lift and 23" tires slower?

[JohnnieB]

Originally Posted by Nicksel1

20psi is what they say max and that's all I have in them. Also. Me and Scotty talked about turning it down to 400 amp. I need to hook up the cable and see what it's getting

Wow, that surprised me. When real world speed is way less than theoretical speed, low pressure tires are often involved.

However, 23" tires take about 20% more torque to turn based on size alone, so the stock PDS motor may not have the wherewithal to turn them faster.

500A is a bit much for a stock motor. The top speed would be the same if it was turned down to 400A since about the only time a motor will draw the max amps a controller will pass is during a maximum effort acceleration from a standstill and then it only draws it for a few yards.

Originally Posted by Nicksel1

And I have 4 gauge cables on battery's and 2 gauge to motor. May upgrade all of them to 2 gauge

I definitely wouldn't hurt to upgrade all 10 high current cables to 2Ga, and it might help quite a bit.

If the cables in the battery pack are the original cables, there is a double whammy.
First and foremost, stock EZGO cables are open ended (Exposed cable conductors) and corrosion creeps into the cable conductors.
Secondly, 2Ga transfers amps more efficiently than 4Ga. Specifically, 59% less power loss.
(IE: 20' of 4Ga looses 50W of power per 100A of current flow, while 20' of 2Ga only looses 31W)

[Nicksel1]

Originally Posted by JohnnieB

Wow, that surprised me. When real world speed is way less than theoretical speed, low pressure tires are often involved.



However, 23" tires take about 20% more torque to turn based on size alone, so the stock PDS motor may not have the wherewithal to turn them faster.



500A is a bit much for a stock motor. The top speed would be the same if it was turned down to 400A since about the only time a motor will draw the max amps a controller will pass is during a maximum effort acceleration from a standstill and then it only draws it for a few yards.









I definitely wouldn't hurt to upgrade all 10 high current cables to 2Ga, and it might help quite a bit.



If the cables in the battery pack are the original cables, there is a double whammy.

First and foremost, stock EZGO cables are open ended (Exposed cable conductors) and corrosion creeps into the cable conductors.

Secondly, 2Ga transfers amps more efficiently than 4Ga. Specifically, 59% less power loss.

(IE: 20' of 4Ga looses 50W of power per 100A of current flow, while 20' of 2Ga only looses 31W)

I think they are all stock actually. They are 9.5 mm on my little micrometer. Anywho, I hooked up the laptop and ran it around town for a bit and played with the throttle settings and ran the logger. Most amperage I seen was around 250 amp? Surely that can't me right?? Had 100% throttle as well. Still seems like I should have more torque, jmo

[Nicksel1]

Also. By your math, the shorter the cable, the better, correct? Obviously I need enough for axle movement and battery movement( if any)......

And the tires have 20 psi in them, wonder what's the max I could throw in them? On my last cart I had low pro tires and ran 50psi

[yurtle]

I wouldn't sweat the cable lengths. A little slack is a good thing, and since you're only measuring 250 amps - which isn't unreasonable if you live in flat areas - you won't tell the difference in an extra foot or so of cable.

[JohnnieB]

Originally Posted by Nicksel1

I think they are all stock actually. They are 9.5 mm on my little micrometer. Anywho, I hooked up the laptop and ran it around town for a bit and played with the throttle settings and ran the logger. Most amperage I seen was around 250 amp? Surely that can't me right?? Had 100% throttle as well. Still seems like I should have more torque, jmo

Amps = Torque and 250A sounds low to me also.

When the armature is sitting still, a motor will suck all the amps it is allowed to draw. The max amps of the motor itself is determined by the DC resistance of its windings and the voltage applied to them. Once the armature starts spinning, other factors come into play and the number of amps a motor, in and of itself, can suck, decreases almost linearly as RPM increases.

Basically it is a supply and demand situation, the motor being the demand, the batteries being the supply and Cables, Solenoid and Controller being the supply chain. (In a series cart, the F/R switch is also part of the supply chain)

The controller limits the number of amps the motor can draw. There are actually two limits. One is the maximum limit determined by design and is typically used to name the controller, (IE: 500A) the other is variable, zero to maximum design amps determined by how far the throttle pedal is pushed by the driver. Other than the controller, the rest of the supply chain should not limit the amount of current the motor is allowed to draw, or the battery pack is allowed to supply.

However, it is impossible to create a supply chain without any limitations at all, so they best we can do it try to minimize them.

The tall tires increase the motor's demand when the armature is rotating, so any limitations that exist in the supply chain and/or supply, are emphasized.

Essentially, with a 500A controller and 23" tires, your cart should be reaching close to 30MPH, or the motor ought to get hot enough to boil water, or burn out.

Originally Posted by Nicksel1

Also. By your math, the shorter the cable, the better, correct? Obviously I need enough for axle movement and battery movement( if any)......

And the tires have 20 psi in them, wonder what's the max I could throw in them? On my last cart I had low pro tires and ran 50psi

Your thoughts about cable length are correct.
Some slack is needed for motor and battery movement (battery frame flexes). Be generous, a foot or so in the total length of all cables, doesn't make a significant difference and too short of cables between batteries will rip the posts out.

A gentle "S" shape acts like a spring and doesn't put as much stress on the posts.

I wouldn't over-inflate them much, if any. Ironically, it might worsen the problem.
Over-inflating will cause the center of the tread to stick out further, increasing the diameter of the tire.

Correct inflation pressure is when the weight is distributed evenly across the tread width.
Place a wet towel behind a front tire, back over it and check the evenness of the damp footprint is leaves on dry pavement.
For back tires, place the wet towel in front of the tire and drive forward.

[Nicksel1]

Also. On my controller the green light always stays on. Did I hook up something wrong? Seems like it should turn off with the key switch?

[JohnnieB]

Originally Posted by Nicksel1

Also. On my controller the green light always stays on. Did I hook up something wrong? Seems like it should turn off with the key switch?

Your controller isn't acting right. Turning off the key or putting the F/R in neutral, ought to shut the controller off.

A DCX in a PDS is almost Plug-N-Play. Almost because you have to use an adapter, but the four connectors on the adapter are physically different, so they cannot be connected incorrectly.

I suspect you have a defective PDS to DCX adapter. (Check for a short between the wire attached to J1 Pin-4 and the diode attached to J1 Pin-3 in the adapter.)

[Nicksel1]

Thought maybe I hooked up the wrong 3 wires on the solenoid from the factory plug?

[JohnnieB]

Originally Posted by Nicksel1

Thought maybe I hooked up the wrong 3 wires on the solenoid from the factory plug?

If the solenoid clicks, you've got it wired right.
Also, there is no way you could miswire those three wires on the solenoid, that would make the controller stay on when the key was off.

[yurtle]

Is it possible the light stays on for a brief period then dims, or should it turn off immediately?