Buggies Gone Wild Golf Cart Forum - View Single Post - 2009 Ezgo 36V Motor & Controller Upgrade disappointment

JohnnieB · 11-07-2019, 02:52 PM

You might be having some battery issues.

The battery voltage (as measured between the XCT's B- and B+ terminals) drops 5V or so when the solenoid contact close. Typically, the battery voltage increases a volt or two when solenoid contacts close.

What is actually being measured between B- and B+ is the voltage on the filter capacitors inside the controller, which are kept charged to a a volt or so less than the battery pack voltage and the go to full pack voltage when solenoid contacts close. The batteries had a bit better charge when the wheels off ground log was recorded, but a 2V drop was still seen.

I also noted the LOBAT error (Low Battery) came on, but only for a moment. Set the Under Voltage slider a little lower.

What is Make/Model of batteries and how old are they?

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The field weakening is fairly conservative. Never went below 3A when in forward and with throttle above 0%.

Was Speed limiting on during the on ground logs?

11-07-2019, 02:52 PM	#3
JohnnieB Techno-Nerd Join Date: Jun 2011 Location: West Virginia Posts: 19,654	Re: 2009 Ezgo 36V Motor & Controller Upgrade disappointment You might be having some battery issues. The battery voltage (as measured between the XCT's B- and B+ terminals) drops 5V or so when the solenoid contact close. Typically, the battery voltage increases a volt or two when solenoid contacts close. What is actually being measured between B- and B+ is the voltage on the filter capacitors inside the controller, which are kept charged to a a volt or so less than the battery pack voltage and the go to full pack voltage when solenoid contacts close. The batteries had a bit better charge when the wheels off ground log was recorded, but a 2V drop was still seen. I also noted the LOBAT error (Low Battery) came on, but only for a moment. Set the Under Voltage slider a little lower. What is Make/Model of batteries and how old are they? -------------------- The field weakening is fairly conservative. Never went below 3A when in forward and with throttle above 0%. Was Speed limiting on during the on ground logs?