more torque needed

[HiTechRedNeck]

Sportcoupe---
Drop lithium in RXV--- Power to weight ratio---
is there any performance boost?
(not expecting a speed increase--acceleration and range benefits?)

[sportcoupe]

I have not done a lithium RXV but generally the advantages are across the board. Speed, acceleration and range will all be greatly improved.

[JohnnieB]

Originally Posted by HiTechRedNeck

..................
Johnnyb-- have you driven a RXV up a hill?
Would love to hear your opinion of their performance. I have limited
experience with upgraded motors and controllers.The ones i have seen
in this area do not impress me.

I've never driven an RXV up a hill, or down a hill, or on what passes for level ground in this area.

I have mixed feelings about RXV's.

A VFD type controller coupled to a 3-Phase induction motor is very versatile, but its versatility has been limited to parameters that the legal department at EZGO finds acceptable rather than what the system is actually capable of. Of course, that same problem exist with DC drive systems, but aftermarket controllers and motors exist for DC systems, so the cart owner can tailor their privately owned property to better suit their wants and needs.

The AC drive system seems to be more fragile than DC drive systems when it comes to adding accessories to the electrical system. I've heard horror stories of people having to replace a $1,500 controller after attempting to add a radio or lights. Granted, you can take out a DC controller if you screw up the wiring, but it fixing your mistake doesn't cost as much.

I love regenerative braking, but as an energy recovery system rather than the primary way to stop the cart. I believe the RXV should have mechanical or hydraulic disks or drums in addition to the electric brakes, preferably attached directly to the wheels rather than the motor shaft.

If the performance parameters allowed by EZGO's lawyers and accountants meet someone's wants and needs, and the factory installed accessories fulfill their desires, than a RXV might be the right cart for them, however I march to the beat of a different drum.

BTW: No need to apologize about the typo. I stopped worrying about how people spell my name ages ago.

[HiTechRedNeck]

Originally Posted by JohnnieB

I've never driven an RXV up a hill, or down a hill, or on what passes for level ground in this area.

I have mixed feelings about RXV's.

A VFD type controller coupled to a 3-Phase induction motor is very versatile, but its versatility has been limited to parameters that the legal department at EZGO finds acceptable rather than what the system is actually capable of. Of course, that same problem exist with DC drive systems, but aftermarket controllers and motors exist for DC systems, so the cart owner can tailor their privately owned property to better suit their wants and needs.

The AC drive system seems to be more fragile than DC drive systems when it comes to adding accessories to the electrical system. I've heard horror stories of people having to replace a $1,500 controller after attempting to add a radio or lights. Granted, you can take out a DC controller if you screw up the wiring, but it fixing your mistake doesn't cost as much.

I love regenerative braking, but as an energy recovery system rather than the primary way to stop the cart. I believe the RXV should have mechanical or hydraulic disks or drums in addition to the electric brakes, preferably attached directly to the wheels rather than the motor shaft.

If the performance parameters allowed by EZGO's lawyers and accountants meet someone's wants and needs, and the factory installed accessories fulfill their desires, than a RXV might be the right cart for them, however I march to the beat of a different drum.

BTW: No need to apologize about the typo. I stopped worrying about how people spell my name ages ago.

Thank You for your reply.

I agree that the limitations on the RXV drive system are artificial not technical.
The top speed is set by law to 20mph, and RXV's will do every bit of 20.
other parameters are reasonably customizable( acceleration/brake aggressiveness) but not nearly as customizable as i have seen in aftermarket
controllers for DC carts. You are Spot on on that point.

AC system Seems fragile----
Yes it seems so, but much of this comes from a misunderstanding of the system.
The wiring to the key switch on most carts is a power wire.
The wire to an RXV key switch is a DIGITAL SIGNAL wire.

Attaching lights or a radio to the key switch on an RXV would be like attaching those accessories to the throttle sensor on a dc cart.

the electrical system on RXV's is very reliable when left alone.
(Yes different drummer-- i own and wear "I void warranties" t shirt
from thinkgeek.com)

If Accessories are added with appropriate 12v voltage reducer attached to 48v pack,I have seen no problems.

If you screw up attaching to wire harness-- yes VERRY EXPENSIVE
I regularly advise folks without digital controller (PLC) or advanced electronics experience to leave RXV harness alone.
Again i agree with you....

Regen braking....
Love regen...having a more normal backup brake would be nice...
On the 2Five-- street legal 25mph RXV, ez go took your advice.
2 fives have 4 wheel disk in addition to regen and electric "parking/emergency" brake.

Please give an RXV a go --- Not a good choice for hard core Modder
like yourself, But in my opinion - a good all around ride.
Balance of performance/safety/comfort and of course legal liability.

Again :
Great information--Thank you for your reply.
If you get a chance to put an RXV through its paces,please post your
thoughts and impressions... I believe many folks value your opinions,
experience and expertise as much as i do.

[cgtech]

Slapping lithiums in an rxv do not give it "crazy acceleration", or any higher top speed at all. They engineered it to accelerate down hill roughly just as fast as it would on flat ground. This also prevents it from doing awesome donuts in dirt lots. It will take "X" seconds to go from speed "A" to speed "B" on any grade. These parameters are quite adjustable on 2012.5 and newer "curtis" model rxv.

[JohnnieB]

HiTech:
Like the RXV, the voltage source for the keyswitch in a PDS cart is the controller, but it is older technology and is it is more or less a feed through rather than a preconditioned or regulated voltage. My guess is that the keyswitch input at the PDS controller is a buffer circuit that knocks the pack voltage level down to the logic voltage level used inside the controller. Too bad the guys that designed the RXV controllers didn't anticipate people hanging stuff on the switched leg.

Dumb question.
If you connect the remote power-on wire of a DC-DC converter to the switched leg of a RVX keyswitch, does it take out the controller?

As for checking out a RXV, I haven't seen any in the area, yet. When I do, I'll try to take it for a spin.

--------------

CG:
So the performance difference between installing a new set of FLA batteries and a new set of lithium batteries in a RXV, is run-time and battery lifespan?

I was aware the top speed is limited by the controller so the reduction in weight wouldn't increase the top speed, but wasn't aware that the acceleration rate was also limited by the controller.

Learn something here almost every day.

[sportcoupe]

Originally Posted by cgtech

Slapping lithiums in an rxv do not give it "crazy acceleration", or any higher top speed at all. They engineered it to accelerate down hill roughly just as fast as it would on flat ground. This also prevents it from doing awesome donuts in dirt lots. It will take "X" seconds to go from speed "A" to speed "B" on any grade. These parameters are quite adjustable on 2012.5 and newer "curtis" model rxv.

I would have thought that shaving 300 lbs off a 1000 lb cart would help with accelleration. I know it did on a TXT for me. Does the RXV controller limit acceleration?

[Kydog]

Originally Posted by JohnnieB

By going from 23" to 25" tires, you only lost 8% of the torque where the rubber meets the road, so the may be some other factors involved.

Do you have a GE1162 or a GE D1162 motor?

Are you running the recommended field map for your motor?
I don't know what it is, but I don't think it is #4.
Call Alltarx to find out and get the correct one if you aren't running it.

Also, what is the pack voltage dropping to when the cart is having trouble climbing a hill?

Your 6 x T-875 battery pack is only a 170AH system while voltage drop under load is determined by how many amps are being drawn relative to AH capacity and a DCX500 feeding a high torque motor turning 25" tires will draw a lot of amps.

Are any cables getting hot?

In other words, your motor and controller may be doing their job, except they are running out of juice.

JohnnieB, what would be the best battery pack for my particular set up? You stated my battery pack is only 170 AH, what would be the optimum battery pack for this cart with the components i have in it. I would like to get maximum power and torque from this set up.
Thanks KyDog

[JohnnieB]

Originally Posted by Kydog

JohnnieB, what would be the best battery pack for my particular set up? You stated my battery pack is only 170 AH, what would be the optimum battery pack for this cart with the components i have in it. I would like to get maximum power and torque from this set up.
Thanks KyDog

Best is akin to beauty, it is in the eye of the beholder.
You've got a few options, some better than others.

The simplest would be higher ampacity 8V batteries like the T-890 (190AH) or the Ranger 160 (204AH).

Looks like you have box for hauling stuff on the rear, so there might be room in the bagwell for a couple of 6V batteries, and you could go to a 8 x 6V 48V system.
Attached is a list of various 48V packs, your pack is in the yellow highlighted area and is the rough eventuality of a stock 36V pack for range. The higher on the list, the better.

The disadvantage of a 8 x 6V pack is that it is heavier than a 6 x 8V system. It is roughly like having a 120 pound passenger in the cart all the time.

Going lithium is also an option, more energy stored in less space and weight, but more expensive.

[Kydog]

i was under the assumtion that AH was more about capacity than anything else, how does that relate to power to the batteries at a given time during acceleration. 48volts is 48volts, i can see if the batteries were low on charge but this happens alittle while after charging. Could there be a bottle neck somewhere else preventing the motor from getting full power?
Dog