36 volt ezgo speed issue

[surfdog]

Hi all, I'm hoping for some help with a 2003 Ezgo pds (the kind with forward reverse on the dash). I bought this cart for my wife to drive around town in Mexico. It's hilly there but most trips are short and the hill we live on is a six minute walk up to our house. When I bought this cart I was planning to convert it to 48 volt, lift it etc. When I drove it, it's top speed is about 6 or 7 mph. and I thought the only way to get it to go any faster was to convert. Meanwhile though I visited a friend with the same cart he drives around his ranch and it goes around 15 mph which actually seems fast enough for our needs. I've also seen several 36 volt carts in our neighborhood in Mex that seem to climb the hill just fine and in general go fast enough that I'm thinking maybe I can just reconfigure what I've got and save some money. So my questions are the following, Why is my cart so slow and how can I get the maximum speed out of it with the stock components?

[JohnnieB]

Originally Posted by surfdog

Hi all, I'm hoping for some help with a 2003 Ezgo pds (the kind with forward reverse on the dash). I bought this cart for my wife to drive around town in Mexico. It's hilly there but most trips are short and the hill we live on is a six minute walk up to our house. When I bought this cart I was planning to convert it to 48 volt, lift it etc. When I drove it, it's top speed is about 6 or 7 mph. and I thought the only way to get it to go any faster was to convert. Meanwhile though I visited a friend with the same cart he drives around his ranch and it goes around 15 mph which actually seems fast enough for our needs. I've also seen several 36 volt carts in our neighborhood in Mex that seem to climb the hill just fine and in general go fast enough that I'm thinking maybe I can just reconfigure what I've got and save some money. So my questions are the following, Why is my cart so slow and how can I get the maximum speed out of it with the stock components?

PDS carts have four performance modes (See attached) and the slowest top speed is about twice of what you are getting, so something is wrong with the cart.

Without being able to see the cart, I'm guessing, but my first three guesses would be bad batteries and/or bad high current cables and/or bad connections.

What is the battery pack voltage when cart is at rest.
What is battery pack voltage when cart is going at its top speed?
Are any of the cables or connections getting hot?

[surfdog]

Thanks for the reply JohnnieB, I am totally ignorant about electric carts and how to check batteries. Can you tell me precisely what to do? I'll clean all the connections though they look ok except for one that has a bit of corrosion on it, I'll make sure it's fully charged and then how do I check the condition of the batteries? The diagrams you posted, is the J2 connector inside the controller? The cart has number 4 cables on it that appear to be in good condition. Batteries I'm not so sure about.
Thanks again

[JohnnieB]

The J2 connector is on the outside of the controller, but you have to remove the environmental cover to see the controller.

The plug in J2 is labeled "Speed Chip" on the first attachment.

Also, be sure to place the Run/Tow switch into the Tow position when removing the controller cover, or disconnecting or reconnecting any wires.
Also, place in Tow if you have to push or tow cart.
Otherwise, you'll ruin the controller.

-----------
The cables on my 2008 PDS cart looked good, but were bad. See second attachment.
I gained low end torque when I replaced them with a complete set of 2G cables.
Of course, top speed stayed the same since the PDS controller limits motor RPM, as determined by which "Speed Chip" is installed.

Note: unless you foresee extensive upgrades to the drive system, 4Ga cable will suffice. Replace all 10 of them.

------
To check battery health:
Charge the batteries until charger shuts off automatically.
Let the batteries rest (Neither charge nor discharge) for 12 hours and then measure the voltages.
The battery pack voltage (From main negative terminal to main positive terminal) should read 38.2V.
Each battery should read 6.37V and all six should be withing 0.1V of each other.

The third attachment is a chart that tells you approximately how much charge is in the battery based on the "At-Rest" voltage.

[surfdog]

Thanks JohnnieB, I did as you said, fully charged, let sit for 12 hours, and tested. The pack was 37.8 and the individual batteries were all 6.28 or 6.29.
Do they need replacement?

[surfdog]

I should add that I checked the J2 connector. It has a yellow wire that goes outside to outside, moderate hills? Do i purchase a new chip or do I add wires to this one?

[surfdog]

Also, is anyone familiar with the Power Wise ezgo charger, model G04. I assume it's not an automatic charger that restarts when the batteries go down.

[JohnnieB]

Originally Posted by surfdog

Thanks JohnnieB, I did as you said, fully charged, let sit for 12 hours, and tested. The pack was 37.8 and the individual batteries were all 6.28 or 6.29.
Do they need replacement?

The batteries are only taking about a 85% charge, so they probably do need to be replaced.

Originally Posted by surfdog

I should add that I checked the J2 connector. It has a yellow wire that goes outside to outside, moderate hills? Do i purchase a new chip or do I add wires to this one?

Either way will work. You can get a "Freedom" chip off e-bay for $10 or less.

Originally Posted by surfdog

Also, is anyone familiar with the Power Wise ezgo charger, model G04. I assume it's not an automatic charger that restarts when the batteries go down.

I suspect there is a 28115 in front of the G04. (See attached)
Automatic only means that the charger shuts off automatically. Typically, when the On-Charge voltage is in the 44V to 46V range for a 36V charger.
The feature of coming back on when battery voltage drops below a predetermined point is typically referred to as a battery maintainer more.

If you have a Powerwise 28115 G04, it is an automatic charger, but does not have a maintainer mode.

[yurtle]

One final thing to check would be to connect the volt meter across the battery pack then drive it. See how low the voltage drops and report back.

[Dave Box]

You are in Mexico = hot, you state that you are totally ignorant when it comes to electric carts so I have to ask, Have you checked the water in the batteries? If not I suggest that you have a look and make sure that the plates are submerged. You must use only distilled water.

Dave