would you stay 36 or go 42? my dilemna

[flharleycop]

I am not up on this like the experts here but I was at a EZGO Dealer in Pensacola, we were talking about range and he knew my cart. He said one of my options with no upgrades was to drop and extra 6v battery for total of 42v. He said my system would work fine with it and they do it regularly. He did say the charger needed to be changed or sent back to Lester for upgrade but that was all I had to do. Just saying what I was told by dealer.

[flharleycop]

Originally Posted by flharleycop

I am not up on this like the experts here but I was at a EZGO Dealer in Pensacola, we were talking about range and he knew my cart. He said one of my options with no upgrades was to drop and extra 6v battery for total of 42v. He said my system would work fine with it and they do it regularly. He did say the charger needed to be changed or sent back to Lester for upgrade but that was all I had to do. Just saying what I was told by dealer.

My cart is a stock 36v PDS

[JohnnieB]

Originally Posted by flharleycop

I am not up on this like the experts here but I was at a EZGO Dealer in Pensacola, we were talking about range and he knew my cart. He said one of my options with no upgrades was to drop and extra 6v battery for total of 42v. He said my system would work fine with it and they do it regularly. He did say the charger needed to be changed or sent back to Lester for upgrade but that was all I had to do. Just saying what I was told by dealer.

I've suspected that was a possibility, but don't know for sure.
My suspicion is based on the fact that people with 42V Western carts have posted the model number of the controller that is installed in their cart as 73326G06, which is the same part number as the controller used in pre-2008 PDS carts.

If the stock PDS controller will tolerate the 16.7% higher voltage, the cart will have more torque and run-time, but the top speed will stay the same since the controller limits motor RPM to 4,400 in freedom mode and less in the other modes.

More torque because a stock PDS controller (300A) with a 36V battery pack, sends 11.5kW to the motor and will send 13.4kW with a 42V battery pack.

More run-time because six 225AH batteries is about 9.0kWh of stored energy while seven 225AH batteries is about 10.5kWh.

With everything else staying the same, the PDS cart will go further on a charge and won't start slowing down as soon on hills or slow down as much.

If the PDS controller works at 42V, about the only issue I see the possibility of reduced regen braking because the pack voltage is more likely to exceed 48V, which is the reduced regen braking trip point.

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Of course, this doesn't help the OP, since he has a Marathon and seven batteries won't fit under the seat like they will in a Medalist or TXT.

[yurtle]

Originally Posted by JohnnieB

If the stock PDS controller will tolerate the 16.7% higher voltage, the cart will have more torque and run-time, but the top speed will stay the same since the controller limits motor RPM to 4,400 in freedom mode and less in the other modes.

I think I remember reading about a magnet "hack" where the number of poles on the speed sensor is reduced, fooling the controller into thinking the rpm is lower than it really is. I have a series, so I didn't really pay much attention, other than thinking it made sense. Is this available for a PDS?

[TxPowderCoater]

dang, you guys are chock full of good info! thanks so much

[JohnnieB]

The speed senor disk has eight magnets and the PDS controller starts cutting back on the duty cycle of the Pulse Width Modulated (PWM) DC being sent to the motor when it sees about 36,000PPS, or about 4,400RPM.

A six magnet disk would allow the motor to spin at 6,000RPM before the controller started throttling back, but the max a stock PDS motor will spin at 36V is about 5,500RPM, however that will give you about 23.5MPH on stock height (18") tires.

Of course, a six magnet disk will give you the full 36% speed increase in the other three PDS mode since the max RPM for them will be less than the max RPM at 36V. (IE: You'd get about 19MPH in Mild Hill mode and still have regen braking)

[flharleycop]

Originally Posted by JohnnieB

The speed senor disk has eight magnets and the PDS controller starts cutting back on the duty cycle of the Pulse Width Modulated (PWM) DC being sent to the motor when it sees about 36,000PPS, or about 4,400RPM.

A six magnet disk would allow the motor to spin at 6,000RPM before the controller started throttling back, but the max a stock PDS motor will spin at 36V is about 5,500RPM, however that will give you about 23.5MPH on stock height (18") tires.

Of course, a six magnet disk will give you the full 36% speed increase in the other three PDS mode since the max RPM for them will be less than the max RPM at 36V. (IE: You'd get about 19MPH in Mild Hill mode and still have regen braking)

where is the magnet disc? Is it hard to change or expensive?

[JohnnieB]

Originally Posted by flharleycop

where is the magnet disc? Is it hard to change or expensive?

Attaches to back end of motor shaft, (Item # 26 in attached)
But I don't know where to find one with fewer magnets.
There are some out there for CC, but I don't think they will fit.

Here is the thread I started on this subject almost two years ago.
http://www.buggiesgonewild.com/elect...eoretical.html

[TxPowderCoater]

crap, thats not rocket science to duplicate, maybe while mine is down for powder work I may tear into the motor and see about making a new one with a strong resin and pour a copy out for grins. seems easy and cheap enough to get a bit more zip from an otherwise stock set up

[porthole]

36 or 48
48 - 6 x 8 or 8 x 6

I can see the obvious improvement of jumping to 48 with a TXT.
But when going to 48, and assuming you know you will be buying a charger, already have a capable controller, solenoids, cabling etc, How do you decide between the 6 or 8 battery combos?

Our cart is mostly used for camping trips for my wife to get around. Figuring we usually have no issue charging it each day, and I doubt it gets more then a mile or 2 miles of use, doe sit really pay to try and squeeze in the 2 extra batteries using the 6's?

Will torque be the same? We do at least one trip a year that has an approximate 6 degree 1/4 mile long hill that we hit at least twice a day for 5 days or so.

Overall cost is something to factor in too for me.
Aside from the charger which is a given, if I go with 8 -6's I can run my pricey HD solenoids (also have the reversing solenoid) off of 6 batteries.

So, 8 x 6 = $$$, use my solenoids
6 x 8 = $$$, buy new solenoids.

Speed is not that big of an issue for us. But some extra torque sure would help just getting it into my toy hauler.
Given occasional use which is better in the long run?