Considering off-lease 2018 RXV - What parts to replace?

[fstop]

I'm considering an off-lease (from a golf course) RXV that would likely be a 2018.

Would plan to dump batteries (to replace with lithium), replace wheels /tires, controller (Navitas), and seats.

I wanted to see what others would suggest to replace (or at least inspect carefully)?

I'd think all bushings in front and rear suspension, and both front and rear shocks (fairly cheap). Rear leaf springs maybe? RXV motor brake?

The off-lease RXVs are so much cheaper than new ones it is hard to consider a new one esp. if you are going to replace some parts anyway (battery, controller, etc...)

Thanks for any insight.

[Chevota Guy]

If it's coming from a golf course it will have the common key switch. A unique key switch is easy to replace and adds security.

I'm not sure I'd get rid of the motor brake if it's only a 2018. Why not purchase a spare and keep it on hand for when the time comes. If the motor brake is a problem, the cart will behave badly, so if it runs fine, I'd let it be.

Another thing to check is the steering linkage, tie rods, front hubs.

[kgsc]

Depending on what your plan is for wheels tires the controller in that cart can really be woken up to better performance than the Navitas. Where are you located?

[BobBoyce]

Originally Posted by kgsc

Depending on what your plan is for wheels tires the controller in that cart can really be woken up to better performance than the Navitas. Where are you located?

I agree. The "600 Amp" Navitas is actually rated at 200 Amps if you use the proper technique for calculating 3 phase AC current. If you use the Navitas method of advertising the rating, then the stock Curtis 235 Amp controller would be rated at 705 Amps! With a bit of reprogramming, the stock Curtis controllers, up to the 1206AC-52XX, can be reprogrammed to go faster and have more torque than its competitor. The Curtis is actually detuned to limit performance...

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Originally Posted by BobBoyce

I agree. The "600 Amp" Navitas is actually rated at 200 Amps if you use the proper technique for calculating 3 phase AC current. If you use the Navitas method of advertising the rating, then the stock Curtis 235 Amp controller would be rated at 705 Amps! With a bit of reprogramming, the stock Curtis controllers, up to the 1206AC-52XX, can be reprogrammed to go faster and have more torque than its competitor. The Curtis is actually detuned to limit performance...

Thanks - I do understand the stock one has a lot more potential (if someone with your knowledge programs it). The Navitas has more potential also, but I doubt they will let it loose.

I have a Navitas Tac2 AC on my Onward and like being able to adjust all the parameters (esp. regen behavior) myself. I'm also used to being able to quickly dial back accel and speed with my phone if someone is borrowing it etc... Also like that I could use 72v lithium packs with it (don't think stock RXV controller will do that?? - not aware anyway). Presumably would need to use the Navitas 4kw or 5kw to go that route, but it's nice to have input voltage flexibility.

I wouldn't plan to build this RXV for max performance - around 30mph would be fine. With that in mind I would plan on leaving in the stock motor rather than getting the Navitas AC 72lb beast.

It may well be wise to start with a reprogrammed controller - point taken. Thanks for pointing it out - I know where to send it

It's really the mechanical wear items I was wondering about mostly - things that go bad, esp. on abused rental carts.

[molfpedal]

I just put my second Navitas Tac 2.0 in a 2011 RXV (the first one lasted 3 weeks) with a 14s 120aH leaf battery pack. The first one would go 32mph w/215-50x12 tires. That is as fast as it can be programmed with the RPM limit on the RXV and stock gears.
As for the rating, I haven’t seen any information that leads me to believe that it is only 200 amps as I saw it send 260 to my cart today with it set at 27mph.
Bob, where did you see this?

[BobBoyce]

Originally Posted by molfpedal

I just put my second Navitas Tac 2.0 in a 2011 RXV (the first one lasted 3 weeks) with a 14s 120aH leaf battery pack. The first one would go 32mph w/215-50x12 tires. That is as fast as it can be programmed with the RPM limit on the RXV and stock gears.
As for the rating, I haven’t seen any information that leads me to believe that it is only 200 amps as I saw it send 260 to my cart today with it set at 27mph.
Bob, where did you see this?

I'm talking about the 3 phase AC drive to the AC motor. You can only read the DC power drawn from the battery on the Navitas. The Curtis 235 Amp controller can draw over 500 Amps DC ftom the battery when set to maximum Accel. Not recommended because it'll do wheelies and can snap axles if done too much. The stock controller can be set for a 72V pack. The hard overvoltage limit to never exceed is 96V.

[molfpedal]

Originally Posted by BobBoyce

I'm talking about the 3 phase AC drive to the AC motor. You can only read the DC power drawn from the battery on the Navitas. The Curtis 235 Amp controller can draw over 500 Amps DC ftom the battery when set to maximum Accel. Not recommended because it'll do wheelies and can snap axles if done too much. The stock controller can be set for a 72V pack. The hard overvoltage limit to never exceed is 96V.

According to Navitas the 600 amps is the maximum AC motor current that can be drawn and it can also be set for a 72v pack.
I went with the Navitas because of the costs associated with converting to even the stock Curtis and that even without a new harness it would have cost more to get the speed that I was looking for.
I actually suggested they should contact you for help with the RXV lithium battery settings.


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[Chevota Guy]

I'll continue to follow this thread with interest. I have an aging 2010 Danaher controller and the options appear to be:

1. Navitas TAC2 direct drop in replacement. Easy for a layman like me.

2. Upgrade to a "tuned" Curtis controller with either a harness replacement or harness modification.

The Curtis has proven the test of time and reliability. The Navitas is the new guy in the neighborhood so the pros and cons are truly confusing.

I like the idea of simplicity and being able to "dial in on the fly" of some critical parameters on the Navitas, but I don't know about longevity and reliability. The Curtis has a long history of good things.

I currently have an aging 2010 Danaher that runs just fine and gives me 24.5 mph which is more than adequate for my needs, but I'm thinking my days may be limited and trying to figure out the next path.

[BobBoyce]

Originally Posted by molfpedal

According to Navitas the 600 amps is the maximum AC motor current that can be drawn and it can also be set for a 72v pack.
I went with the Navitas because of the costs associated with converting to even the stock Curtis and that even without a new harness it would have cost more to get the speed that I was looking for.
I actually suggested they should contact you for help with the RXV lithium battery settings.

Exactly, their spec is that the 3 phases are 200 Amps each which they add up to equal 600 Amps. An engineer should know, that is not the way to actually calculate delivered Amps. If Curtis were to use that method, their stock 235 Amps per phase controller would be rated for 705 Amps. They know to only count the current of one phase, since they are in balance... With 3 phase, there are factors that can result in unbalanced phases. Smoothest and most efficient operation occurs when the phases are adjusted to be exactly balanced. There are adjustments to do that in a Curtis controller.

I really like that they came out with an aftermarket 3 phase AC controller. That gives options, and it threatens Curtis with the knowledge that they are not the only option for affordable AC drives! I just wish that they had made it as adjustable as the Curtis, and were more honest with their rating. They are counting on the ignorance of prospective buyers to not know the complexities of calculating 3 phase AC Amps. To me, that is a bit dishonest. I figured if I pointed that out enough times, they would get the hint. Other than those points, I would be happy to promote them. I can understand why they would not allow the average user to not allow balancing of the phases, because users would royally stuff up their balance. But advanced programmers that know their stuff may need to be able to rebalance as a controller ages.