Speeding up PDS, Battery Voltage

[JohnnieB]

Originally Posted by tmbrown89

Hey johnnieb can you help me. I seen this post and need help understanding the ITS.


Re: 2008 EZGO PDS Cart
Quote:
Originally Posted by JohnnieB
In your first post you stated you've checked the ITS (Hopefully, you verified the ITS voltage to the controller was in specs) and replaced the Speed Sensor in the motor.
Soon after I got my buggy, I adjusted the plunger in the ITS using a drill bit to get the proper distance, with info located somewhere in the stickies. If I recall, you also have to adjust when the micro engages. Once I did that, I got a noticeable speed improvement, as the controller was never told by the ITS to go to 100%.

For straters, I'm being misquoted.
Here is what the post being quoted actually looked like:

Originally Posted by JohnnieB

In your first post you stated you've checked the ITS (Hopefully, you verified the ITS voltage to the controller was in specs) and replaced the Speed Sensor in the motor.

Originally Posted by yurtle

Soon after I got my buggy, I adjusted the plunger in the ITS using a drill bit to get the proper distance, with info located somewhere in the stickies. If I recall, you also have to adjust when the micro engages. Once I did that, I got a noticeable speed improvement, as the controller was never told by the ITS to go to 100%.

------------------
And here is my complete post that yurtle quoted a portion of in his post.
The part he used is highlighted in blue.

Originally Posted by JohnnieB

I think your batteries are showing their age, but they are staying close together in voltage, so none have a bad cell.

You didn't specifically say, but I take it that the cart was still slow with the battery pack at 37.6V (85% SoC) and above.
My cart still does about 18MPH @ 85% SoC, so while your batteries aren't up to par, I don't think they are the primary reason for the slow speed issue.

In your first post you stated you've checked the ITS (Hopefully, you verified the ITS voltage to the controller was in specs) and replaced the Speed Sensor in the motor.
In your latest post you state the none of the cables or motor are getting hot after 15-20 minutes of pedal time.
If you had a mechanical drag of some type slowing you down, the motor would have been pretty hot.

That eliminates everything except controller, solenoid and motor.

If the cart is running smoothly, but slow, and the motor isn't getting hot, the motor is probably okay.

To eliminate the Solenoid as the culprit, attach your DVM across the big terminals and measure the voltage while driving cart.
It should not read more than a volt or so, if any, when the cart is at max speed.

If the solenoid is okay, I'm afraid it is time to replace the controller.

PDS controllers have some weaknesses, so when mine goes I'm going to replace it with an aftermarket one.
I'm not making a suggestion or recommendation, just providing some food for thought.

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ITS is an acronym for Inductive Throttle System.
It consists of a coil of wire (sensor) and an iron slug (plunger)
As the iron slug is inserted into the coil, the coil's inductive reactance increases and the current passing through it develops more voltage.
Basically, it acts like a variable resistor (potentiometer), but without the physical contact between the resistive element and wiper arm, which gets dirty and wears out and can cause problems in the potentiometer type throttles.

Series carts, PDS carts and DCS carts and maybe the RXV carts, all use the same sensor coil, but the controller supplies the current that feeds it and there are differences in the amount of voltage that is measured and if an increase in voltage or a decrease in voltage tells the controller to allow the motor to draw more current, so the checkout procedure is controller specific and aftermarket controllers are not necessarily the same as the stock controllers they replace.

Fortunately, the mechanical adjustments are about the same for all.
Basically, you want the NC contacts of pedal microswitch to close before the plunger enters the sensor and you want the plunger fully inserted, or beyond, when the pedal is on the floor.

[yurtle]

Here's what I was referring to.

Owner's, Parts, and Service Manuals:
http://www.buggiesgonewild.com/elect...g-manuals.html

Mechanically, the info in the stickies should be the same, regardless of drive type, as far as adjustment.

[tmbrown89]

Thanks yall for the info, JohnnieB I opened my controlled bow up last night to find out the company that built my cart for me did not put the freedom chip in it. They just put the mild hill chip in it. I made the jumper wire with the diagram from you and it opened it up alot and also removed the engine braking.

My next question - I read on a forum here about drilling a hole somewhere on the on the ITS to give it a bit more speed..

Can you give me some direction on this?

[tmbrown89]

I mean controller box not bow lol sorry

[JohnnieB]

Originally Posted by tmbrown89

My next question - I read on a forum here about drilling a hole somewhere on the on the ITS to give it a bit more speed..

Can you give me some direction on this?

I've never heard of that one. The ITS sensor is a coil of wire and drilling holes into it would ruin it.
On top of that, the PDS controller limits motor RPM to about 4400RPM in Freedom mode and even if the ITS put out more, the motor wouldn't spin any faster.

One way to find out if the ITS is turning the controller all the way on is to connect a DVM between the B- and M- and measure the voltage. (M- might be labeled A1 on a PDS controller)
When solenoid first clicks, you should read FULL battery pack voltage
When pedal is on floor, the voltage will be zero, plus about 0.5V for every 100 Amps of current flowing through the motor.

But remember, when the motor hits about 4400RPM (About 18MPH with stock height tires), the controller will back off an the voltage will go up, so it will only be zero while accelerating, or climbing a steep hill. One steep enough top slow cart down significantly.

[tmbrown89]

Awesome, Thank you so much for the info.

I will be upgrading the motor, controller and wires soon.

Any recomendations on motors?

[tmbrown89]

Will the freedom chip hurt my cart running it wide open?

[JohnnieB]

Only if you hit a tree.

Running a PDS cart wide open in any of the four PDS modes, doesn't hurt it.
What hurts it is heat and creeping around at slow speeds and climbing hills that are too steep, generate more heat in the motor and controller than running wide open does.

You can creep around at little more than walking speeds and climb some mighty steep hills, just don't do it excessively.

[tmbrown89]

cool, thanks.

Hows your cart coming along?

[JohnnieB]

Got all the stuff, New batteries (and old batteries) are on float charge.
Just waiting for some warmer weather to install everything.