EZGO TXT speed issue already replaced motor and batteries

[genoz]

I just did a load test around the block a few times. Each battery is about 5.7v when fully accelerated. The pack is 35.6v. Below are the pictures of the batteries and the charger. The batteries are 3 months old. The charger came with the cart. Do you think I can add another battery since I already seem to have an upgraded controller?

[JohnnieB]

The Deka GC-15 is a 6V - 230AH battery. Ought to be okay.

The charger is a PW 28115 and ought to charge those batteries adequately.

What is the pack voltage about 12 hours after charger shuts off? (Ought to be 38.2V - see attached chart)

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You have a different controller than what is typically found in a 2000 series drive EZGO golf cart, rather than an upgraded one.

The typical one is a Curtis 1206 which is a 275A controller. You have a Curtis 1205, probably the 400A versions, which runs on 24V through 36V. Attached is the manual for 12204/5 controllers and near the back of it are the voltage specs of the various versions.

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Also, the go to 42V, you'd need a solenoid and battery charger.

For the time being, lets determine if the batteries are being fully charged.

[genoz]

I will check it and let you know. Thanks!

[genoz]

I checked the voltage after charging and letting it sit for 12 hours. The pack is at 38.6 volts. Still only getting 19mph.

[JohnnieB]

It appears that the batteries are being well charged, but the top speed depends on the voltage applied to the motor, however how far the voltage drops when amps are drawn from it depends on storage capacity, which in turn depends on the battery temperature.

Batteries have a huge thermal mass, so use the previous night's low temperature as the battery temperature to use the attached chart.

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Also, measure the voltage between the controller's M- and B+ terminals when traveling at top speed with pedal on floor. That will tell us what the voltage being applied to the motor is.

[genoz]

So do you think it would be worth it to add another battery? If so could I use my current speed controller and charger? Is there any way to wire it so that I could just charge the one battery separately? Thanks in advance!

[cgtech]

Your stock controller is known for thermal issues already, adding 6v more (above its rating) isn't gonna help controller life.

[genoz]

Ok thanks! I thought that since I seemed to have a different controller than stock it might work.

[cgtech]

I believe you have the stock HD version, 400a. But that doesnt change its voltage rating.

[genoz]

Im thinking about purchasing a Sr-48300. Would that get me more speed with the current setup?