Checking my RPM

timmyjane · 03-26-2016, 10:53 PM

What do yall think the best way to check/montior my RPMs would be? I have a feeling that something may be up with my motor. I upgraded to 48v and a 500A controller and I really cant tell a difference from when it was a 36. Makes me wonder if the motor is performing as it should.

Revolution · 03-26-2016, 11:23 PM

36 volt stock to 48 volt 500 amp should be a HUGE kick it the seat. Also know as increasing your top speed by at lest 20% and getting there faster.

Check the basics first. Is your pack fully charged?<post the full pack voltage.

Check ALL your connections, I mean every last one.

Check your controller settings.

Give us some more details like:

Is your battery pack new?

Six, eight, or twelve volt batteries?

What brand and amp hour rating?

What brand, voltage and amp rating is your charger?

It is totally possible there is something wrong with your motor. Brushes wear out, but they are relatively easy to replace. Windings can get too hot and short out, causing a loss of performance. Carbon build up from the brushes can cause some performance loss.

kgsc · 03-27-2016, 08:22 AM

And is anything getting warm?

timmyjane · 03-27-2016, 09:09 AM

Quote:

Originally Posted by Revolution

36 volt stock to 48 volt 500 amp should be a HUGE kick it the seat. Also know as increasing your top speed by at lest 20% and getting there faster.

Check the basics first. Is your pack fully charged?<post the full pack voltage.

Check ALL your connections, I mean every last one.

Check your controller settings.

Give us some more details like:

Is your battery pack new?

Six, eight, or twelve volt batteries?

What brand and amp hour rating?

What brand, voltage and amp rating is your charger?

It is totally possible there is something wrong with your motor. Brushes wear out, but they are relatively easy to replace. Windings can get too hot and short out, causing a loss of performance. Carbon build up from the brushes can cause some performance loss.

New Interstate Batteries
6-8V
New DPI charger
Not sure what controller settings you want. Its mostly still as it came form the factory.
All connections should be tight. I changed out the battery cables and triple checked that they were tight.

Quote:

Originally Posted by kgsc

And is anything getting warm?

Ill check. Good advice.

JohnnieB · 03-27-2016, 10:23 AM

Motor RPM can be calculated from cart speed if you know the gear ratio of the differential gears and the tire height.

For most TXT and Medalist carts, the gear ratio is 12.44:1 and the stock tire height is 18", so the motor spins 232.31 RPM per MPH.

A typical TXT series drive cart does about 14 MPH (3252 motor RPM) with a 36V battery pack and with a 48V battery pack it will do about 18.7 MPH (4335 motor RPM).

Different tire heights and/or differential gear ratios will produce different speeds.

Whatever your cart speed was at 36V, increase it by 1/3 (33.3%) to get what your cart should be getting at 48V. In reality, your cart probably won't get the full 33.3% speed increase due to other factors involved, but it ought to come pretty close to it. IE: 18.5 MPH or better.

-----------
Your new Interstate batteries won't reach their rated storage capacity until they are broken in, but that mostly effects run-time rather than speed or torque and you should be getting close to a 33.3% increase in both.

-----------
Attached is a cut and paste from the Tool Kit manual showing the controller setting screen. (Disregard the values shown, they don't apply to anything outside the mind of the tech-writer that wrote the manual.)

What values are the sliders set for in your controller?

If possible, post screen saves for all the screens for your controller.

Also, check for error codes.

timmyjane · 03-27-2016, 09:11 PM

Attached are the screen shots. I haven't GPSd so I dont know the actual speed. I can only say that there doesnt appear to be much of a difference from before all the upgrades.
Oddly Alltrax Toolkit kept crashing when I opened it so I had to run as administrator.
I noticed the voltage displayed in the monitor is not right. Per my multimeter and dashboard monitor I have 52.7v but Alltrax is reading 50.1v. However I did install the in dash meter this morning in order to aid in diagnostics so I havent had a chance to ride and monitor the voltage drop on the road.

Thinking about it the DPI was plugged in when I took these screen shots and the multi meter test so the voltage may be off because of that. The chrger wasnt making any noise but it could have been doing some type of trickle charge I guess.

Revolution · 03-27-2016, 10:00 PM

Is it possible Timmyjanes controller thinks is in reverse while going forward? I don't know stock Ezgo wiring, but if forward reverse was backwards the %50 reverse speed setting could be keeping it feeling like a 36 volt cart.

Timmyjane, if it were my cart and I wasn't 100% sure the wiring was right I would spend five minutes and set the reverse speed setting to %100 and see what the cart does in forward.

timmyjane · 03-28-2016, 06:53 AM

I'll give it a shot but I don't think it's that slow.

JohnnieB · 03-28-2016, 09:07 AM

The battery voltage the controller monitor is displaying is lower than pack voltage because the solenoid's contacts aren't closed.

Measure between the controller's B- and B+ terminals with a DVM and it will match the monitor reading.

After the solenoid clicks, it will be full battery pack voltage, before it clicks, it'll be whatever the charge is on the filter capacitors (Via the pre-charge resistor).

-----------
At 55V, the "Over Voltage" slider might be set too low. The absorption charge phase of a DPI charger exceeds 55V and climbs higher still in the finish phase. Granted, float charge mode is less than 55V, but between the time the regular charge ends and the pack self-discharges down to the float charge voltage level, the controller will be in an over-volt error. I'm not sure if that puts the controller in a reduced performance mode or shuts it down, but I'd move the slider all the way to the right for >60V.

-------------
What is your actual tire height?

Measuring with yardstick and level is close enough to calculate the theoretical speed you should be getting at 48V.

timmyjane · 03-28-2016, 06:15 PM

Well I guess the cart is doing what it is supposed to do. I GPSd today and was hitting 18 on slight downhill maybe about level, 15 on slight uphill. 21 down a long maybe 8-10 degree downhill. Tires are 19.75 inches tall.

Not sure if this is normal but voltage hung out around 47.2-5. A few times it dropped to 44,x when I punched it but mostly around 46 when I hit the throttle. It would climb to 48.2-5 when going on slight declines. After I got back home and parked it went to 50.1 in a few seconds after I parked.

Does all that seem normal?

03-26-2016, 10:53 PM	#1
timmyjane Gone Wild Join Date: Jul 2015 Location: Simpsonville, SC Posts: 245	Checking my RPM What do yall think the best way to check/montior my RPMs would be? I have a feeling that something may be up with my motor. I upgraded to 48v and a 500A controller and I really cant tell a difference from when it was a 36. Makes me wonder if the motor is performing as it should.

03-26-2016, 11:23 PM	#2
Revolution Voltaholic Join Date: Dec 2013 Location: Close to Navasota Texas Posts: 934	Re: Checking my RPM 36 volt stock to 48 volt 500 amp should be a HUGE kick it the seat. Also know as increasing your top speed by at lest 20% and getting there faster. Check the basics first. Is your pack fully charged?<post the full pack voltage. Check ALL your connections, I mean every last one. Check your controller settings. Give us some more details like: Is your battery pack new? Six, eight, or twelve volt batteries? What brand and amp hour rating? What brand, voltage and amp rating is your charger? It is totally possible there is something wrong with your motor. Brushes wear out, but they are relatively easy to replace. Windings can get too hot and short out, causing a loss of performance. Carbon build up from the brushes can cause some performance loss.

03-27-2016, 08:22 AM	#3
kgsc Gone Wild Join Date: Dec 2009 Location: Aiken, SC Posts: 13,141	Re: Checking my RPM And is anything getting warm?

03-27-2016, 10:00 PM	#7
Revolution Voltaholic Join Date: Dec 2013 Location: Close to Navasota Texas Posts: 934	Re: Checking my RPM Is it possible Timmyjanes controller thinks is in reverse while going forward? I don't know stock Ezgo wiring, but if forward reverse was backwards the %50 reverse speed setting could be keeping it feeling like a 36 volt cart. Timmyjane, if it were my cart and I wasn't 100% sure the wiring was right I would spend five minutes and set the reverse speed setting to %100 and see what the cart does in forward.

03-28-2016, 06:53 AM	#8
timmyjane Gone Wild Join Date: Jul 2015 Location: Simpsonville, SC Posts: 245	Re: Checking my RPM I'll give it a shot but I don't think it's that slow.

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03-28-2016, 09:07 AM	#9
JohnnieB Techno-Nerd Join Date: Jun 2011 Location: West Virginia Posts: 19,654	Re: Checking my RPM The battery voltage the controller monitor is displaying is lower than pack voltage because the solenoid's contacts aren't closed. Measure between the controller's B- and B+ terminals with a DVM and it will match the monitor reading. After the solenoid clicks, it will be full battery pack voltage, before it clicks, it'll be whatever the charge is on the filter capacitors (Via the pre-charge resistor). ----------- At 55V, the "Over Voltage" slider might be set too low. The absorption charge phase of a DPI charger exceeds 55V and climbs higher still in the finish phase. Granted, float charge mode is less than 55V, but between the time the regular charge ends and the pack self-discharges down to the float charge voltage level, the controller will be in an over-volt error. I'm not sure if that puts the controller in a reduced performance mode or shuts it down, but I'd move the slider all the way to the right for >60V. ------------- What is your actual tire height? Measuring with yardstick and level is close enough to calculate the theoretical speed you should be getting at 48V.

03-28-2016, 06:15 PM	#10
timmyjane Gone Wild Join Date: Jul 2015 Location: Simpsonville, SC Posts: 245	Re: Checking my RPM Well I guess the cart is doing what it is supposed to do. I GPSd today and was hitting 18 on slight downhill maybe about level, 15 on slight uphill. 21 down a long maybe 8-10 degree downhill. Tires are 19.75 inches tall. Not sure if this is normal but voltage hung out around 47.2-5. A few times it dropped to 44,x when I punched it but mostly around 46 when I hit the throttle. It would climb to 48.2-5 when going on slight declines. After I got back home and parked it went to 50.1 in a few seconds after I parked. Does all that seem normal?