question

[USER973783]

1998 EZGO Freedom(Stock Curtis 1206 controller) Added 7th battery.

Charged with 42 volt Lestronic Charger.

Turned her on and "click" no go.

Put her back to 36 volts and normal - 21 mph

Put her back to 42 volts and GREAT - 23+ mph

Ran around and put her back on charger.

Turned her on and "click" no go.

Put her back to 36 volts and normal.

Whats happening?

[JohnnieB]

You are hitting the controller's over voltage shutoff. Fresh off the charger, a 42V pack will be at 50V or above.

Let the batteries rest for a while to deplete the surface charge and the cart will run.

What type drive, series or sepex?

With a stock PDS motor and stock height tires, I got 24MPH @36V and 28MPH @42V.

[sportcoupe]

I wish 42v chargers were more plentiful and cheap.

[USER973783]

If I increase the value of the solenoid resister will this cure the problem? I believe this is the only current path to the controller during charging.

Whats the downside of eleminating the resistor?

Series Drive.

[JohnnieB]

Changing the resistor won't solve the "problem".
It isn't a "problem" because that is the way it is designed and it isn't being used in an application it was designed for.
Nothing except a controller designed for a higher voltage will eliminate the issue.

What is happen is, the 42V pack ends up having 50V or so when the charger turns off and the 36V controller's over-volt shutoff is set to about 48V. The pack voltage starts decreasing the instant the charger shuts off, but it takes some time for the voltage to decrease below 48V, or what ever the over-volt is set to.


The Over-Volt shut-off on a 1206MX (PDS) is set for 48V - I'm not sure about the other two versions, but they are probably the same since they are all three designed for 36V applications.

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The downside of removing the resistor is increased arcing and pitting on the solenoid contacts.

[USER973783]

1206.

What if I put a switch on the resistor and shut it off during charging? From the 1206 diagram it tells me this the only current path to the controller during the charge cycle.

[JohnnieB]

Originally Posted by USER973783

1206.

What if I put a switch on the resistor and shut it off during charging? From the 1206 diagram it tells me this the only current path to the controller during the charge cycle.

Changing the ohmic value or, or eliminating, the resistor across the solenoid's large terminals will not change the fact the controller will have a voltage above the factory preset Over-Volt shutoff voltage applied to Pin-4 when the pedal is pushed.

What the pack voltage is or isn't while the batteries are charging, simply does not come into play here.
The issue is what the pack voltage is after the charger is unplugged from the cart.

A 42V battery pack will measure someplace between 51.5V and 58.5V when the charger shuts off and 12 Hours later, it will measure 44.6V.

Short of replacing the controller with one designed for a higher voltage, the only options you have are waiting until the pack voltage naturally drops below the controller's Over-Volt cutoff or figuring out some way to draw a few amps from the pack to reduce the wait time.

[USER973783]

What controller do you reccommend?

[sportcoupe]

If you have lights turn them on for a few mins. That will bleed off the excess overvoltage charge enough to get the controller to function normally.

Do you really want to spend $300-600 on a controller right now? If moneys no object or you just crave more torque then go for it. Call ScottyB monday and he will hook you up.

[JohnnieB]

Something programmable like an Alltrax AXE or SPM.

The amp rating should match you setup and to get 21MPH @ 36V and 23MPH @ 42V with a 98 Series cart, you've got to be running tall tires and/or long gears and/or a high speed motor. (Or you need a better speed measuring device. )

The text at the top of this page gives a pretty good overview of things to take into consideration when upgrading a drive system. http://www.cartsunlimited.net/Custom_Options.html

Like sportcoupe said, you can bleed of the voltage with lights or something.

Most of the voltage bleed off occurs in the first hour, so even if you don't bleed it off, the pack voltage will probably drop low enough for the cart to run in 15 to 30 minutes after charger shuts off.