75 Rupp Centaur

xXSaneXx said:
Why do I need a series of 14v to reach a 72v? Why can't I just buy a 72v50-80ah battery with Samsung cells with 300-400 bms current, with a peak of 420 to 560amps?
Id think that would be perfect as it's a battery that supports up to almost 40k watts. Volts x amps
Then with the controller 500a with peak of 1000a so it should carry that little 3 wheeler quite well in takeoff an performance for what I want. The controller I'm looking at is recommended for lightweight electric vehicles. This thing is NOT heavy lol For some reason some of you guys think I'm trying to power a car. Lol
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You could go that route, if you want. Nobody is stopping you. It's just that you're getting multiple accounts suggesting that a 72v50ah battery isn't going to get you the range that you're hoping for. You asked for advice, and the advice is to go bigger. You don't have to follow said advice.

We suggest automotive modules because their often a much better quality, higher performance, and lower cost, while often being constructed in heavy-duty and easy to assemble units. They are also usually cheaper per kwh than premade packs like Amorge, and they'll likely last longer.
 
Ok but a prem
harrisonpatm said:
You could go that route, if you want. Nobody is stopping you. It's just that you're getting multiple accounts suggesting that a 72v50ah battery isn't going to get you the range that you're hoping for. You asked for advice, and the advice is to go bigger. You don't have to follow said advice.

We suggest automotive modules because their often a much better quality, higher performance, and lower cost, while often being constructed in heavy-duty and easy to assemble units. They are also usually cheaper per kwh than premade packs like Amorge, and they'll likely last longer.
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Adequate pack would suit me best because idk how to put packs together like most keep suggesting. The 72v50-80ah is used on motorcycles as well so why exactly would it not work? I'm not looking to go 100mph or 100 miles in range. It's a short trip cruiser toy. I'm not interested in long rides. If it goes 30 miles in range for start an does over 45mph that's fine. I'm not making a race bike like most the guys with razors an surrons do lol
 
xXSaneXx said:
Ok but a prem

Adequate pack would suit me best because idk how to put packs together like most keep suggesting. The 72v50-80ah is used on motorcycles as well so why exactly would it not work? I'm not looking to go 100mph or 100 miles in range. It's a short trip cruiser toy. I'm not interested in long rides. If it goes 30 miles in range for start an does over 45mph that's fine. I'm not making a race bike like most the guys with razors an surrons do lol
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A premade*
 
I mean, if you can afford a pre-made 72v80ah pack, then sure, that's the best thing one can get now, especially on 21700 cells, and that's what powers the best motorbikes out there right now. I think the reason why people are recommending larger batteries is that since you do have the extra space, you can make the build slightly differently.

When building a small battery, you have to choose between large capacity cells, high power cells or very expensive cells. Thing is, the more battery you add, max power becomes less of a problem, since you can spread the current over many more P cells. At a sufficient size, you can get largest capacity cells available with small power rating, without paying the premium for high discharge, while the entire pack can still supply the amperage needed.
 
How much does the trike weigh, 500-700lb.? Is that with or without rider(s)?
 
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As I said if you chose Amorge it will be like 3+ times the price for 1/3 of the battery capacity.

If you don't care about cost, just go for Amorge. I don't know exactly how the tariffs works but as I understand you will have to pay 54% extra on those batteries now. I personally would just buy from battery hookup but you do as you please.

Regarding the larger motor and controller, just because your controller can deliver a lot of power doesn't mean you have to use it. A larger controller will be running cooler and you have that extra power if you like. You just set it up as you like, if you want to limit the power to let's say 10kw, you just do that.
 
hugok said:
As I said if you chose Amorge it will be like 3+ times the price for 1/3 of the battery capacity.

If you don't care about cost, just go for Amorge. I don't know exactly how the tariffs works but as I understand you will have to pay 54% extra on those batteries now. I personally would just buy from battery hookup but you do as you please.

Regarding the larger motor and controller, just because your controller can deliver a lot of power doesn't mean you have to use it. A larger controller will be running cooler and you have that extra power if you like. You just set it up as you like, if you want to limit the power to let's say 10kw, you just do that.
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It's not the cost part, it's more like idk what's involved in putting multiple battery packs ect. Someone said to use a battery from a electric car. The batteries qre to big. I was thinking amorge because it's already put together and I dint have to worry bout me screwing up on putting multiple battery packs together ect. Lol
 
xXSaneXx said:
It's not the cost part, it's more like idk what's involved in putting multiple battery packs ect. Someone said to use a battery from a electric car. The batteries qre to big. I was thinking amorge because it's already put together and I dint have to worry bout me screwing up on putting multiple battery packs together ect. Lol
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I was in the same boat where I didn't know a lot of stuff involved in doing an EV conversion, but I was able to learn a whole lot from this forum. If you decide to go down the path of combining battery packs you can easily get help from the super knowledgeable people here. I'd read as many build threads and ask as many questions as you can.

I personally went with getting a premade pack from Amorge and it worked pretty well for me. I also didn't want to have to worry about me screwing up and causing a battery fire between my legs while riding. The Amorge battery I got came with a bluetooth BMS (battery management system) which is a really useful feature. It also came with QS8 connectors which have a precharge resistor built in which is pretty cool.

The cool thing about doing your own conversion is that you learn a bunch of stuff doing it, and if cost isn't an issue you can always upgrade it later on. That being said, I'd definitely lean towards more battery to begin with. You might kick yourself for not having enough battery, but you won't regret having more power than you need.
 
I was looking at other electric motor options. Would the geared qs138 be a better option?Does that mean there is a gear to shift to or does that mean it has like 3 modes? Would a direct drive qs138 be better for this? I'm thinking I'll use 1 motor, chain driven to start an then eventually and another gear to the axle adding another motor so I'll have a motor for both rear wheels. I'm dropping to a atv style wheel, lighter, an with a meatier tire. I was thinking the lines of a 12 or 13inch tire, less to spin. I currently have a 15x7 with 195/55/15 tires. The shorter tires in rear (matching close to the original 13inch wheels that were in rear) giving it much better acceleration and with a controller I can set to speedometer with the correct mileage it's actually going. The front wheel is a 16inch, unknown of the tire size but I'm going to go with a sport bike style tire. With the rear wheel an tire setup the rear will sit lower.
As far as a battery I been exploring options.i have room for a golf cart type battery, think they would work?
 
xXSaneXx said:
I was looking at other electric motor options. Would the geared qs138 be a better option?Does that mean there is a gear to shift to or does that mean it has like 3 modes? Would a direct drive qs138 be better for this?
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QS138v3 has a 2.35:1 reduction gearbox permanently mounted to the motor. It makes it a better fit for motorcycle wheels, as then you can use regular drivetrains (or closer to regular than would otherwise be necessary).

If you plan on using very small wheels, you'll need to spin them quite fast, and then the non-reduction motor might be a better choice. It's quite easy to calculate - take the desired wheel circumference, multiply by the max (or optimal) motor RPM for your powertrain, multiply by all gearing in the process, and you'll get the speed. You'll want to target around 75% of the non-flux-weakened max RPM you can get for your target cruise speed. Knowing all that, it should be easier to choose.
 
bananu7 said:
QS138v3 has a 2.35:1 reduction gearbox permanently mounted to the motor. It makes it a better fit for motorcycle wheels, as then you can use regular drivetrains (or closer to regular than would otherwise be necessary).

If you plan on using very small wheels, you'll need to spin them quite fast, and then the non-reduction motor might be a better choice. It's quite easy to calculate - take the desired wheel circumference, multiply by the max (or optimal) motor RPM for your powertrain, multiply by all gearing in the process, and you'll get the speed. You'll want to target around 75% of the non-flux-weakened max RPM you can get for your target cruise speed. Knowing all that, it should be easier to choose.
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I think after some more research I'll use a qs138 90h without the gearing. I'm looking at controllers. I was recommended a em550 and to go with a 96v battery. I know alot of you are saying buy battery packs an put them together an run them in sync to work together. He's one do that when they have never put one together? I read you need to buy a bms pack too? Am I misunderstanding this? I'd probably be better off buying the stuff an have a experienced person put them together. If starg vark weren't so expensive I'd get a battery like there's. I wouldn't know what to get to make something close to or similar.
 
So ive changed a couple things. I know someone mentioned a qs165. That will struggle as its much smaller an is ment for mini bikes. Motor is removed, along with cvt, gas tank, all the old wiring. Took it to a weighing scale. The frame, fiberglass body, 2 wheels an front end all together weighed in at a massive 298lbs. So apparently it had alot of weight in the rear.
So im going with this
1pcs x QS180 8000W Mid-drive Motor With 428 Sprocket
1pcs x Far-driver Controller ND961000B With Bluetooth
1pcs x 3.6inch round TFT CJ Display
1pcs x Twist Throttle
1pcs x Main Wiring Harness
1pcs x 72V-12V 10A DC/DC Conveter
1pcs x Flasher and Ingition
The battery im still looking at options.
Surron has a 96v battery, 96v lithium golf cart batteries.
 
QS165 is actually two motors - one is a small pancake that fits surrons (35H I believe?) and the other is much larger than the 138-70H, about the weight of the 90H but supposedly more powerful, and only comes with reduction. That's the 165-60H.

180 is a giant beast even more so than the above, but for this vehicle it should be just fine.
 
I see this vehicle for sale unmodified on Florida Marketplace. Its so easy to get overwhelmed with major projects.
 
Its way better to sell now than start something you'll likely not finish. Personally I'm waiting for solid state batteries before I'll invest the time and effort into a major conversion project. That one is also a good candidate for a motorcycle engine swap too. If I remember, they had serious overheating issues back then. Not surprising with a snowmobile engine stuck in summer traffic.
 
hobbyvac said:
Its way better to sell now than start something you'll likely not finish. Personally I'm waiting for solid state batteries before I'll invest the time and effort into a major conversion project. That one is also a good candidate for a motorcycle engine swap too. If I remember, they had serious overheating issues back then. Not surprising with a snowmobile engine stuck in summer traffic.
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Wasn't really over heating issues. The snowmobile motors gearing made it rev to high. Im just shocked its been on there since 7pm yesterday an almost 1000 views.
 
Torque converters work great if you don't mind driving around at peak torque rpm of around 5000 all the time Its kinda stupid if your going slow and only need a few HP. A goldwing motor would make that thing purrr
 
hobbyvac said:
Torque converters work great if you don't mind driving around at peak torque rpm of around 5000 all the time Its kinda stupid if your going slow and only need a few HP. A goldwing motor would make that thing purrr
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Common swap is actually a vw motor as thats what they originally were built for but the deal with rupp an vw fell through so they used the snowmobile motor instead.
 
hobbyvac said:
I see this vehicle for sale unmodified on Florida Marketplace. Its so easy to get overwhelmed with major projects.
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I removed it. People were sending me offers an then I never hear from them. So I been building ebikes on the side and selling them. They money I get from them ill start buying things for it. Ill sell the things off the rupp im not using. The stock rupp harness, rpm gauge (unless it can work with a electric motor) i have 3 haha! I have a couple pares of mikuni carbs, a hyabusa disc brake front rotor, the actual kohler motor (it ran before i got it so it does run)

Then ill just buy parts separately. Fardriver nd721800b controller with a full harness with the dc 12v converter, with the 3.6inch round digital screen, the switch to allow it to go in reverse. Im hoping i can use my forward an reverse gear somehow. The wiring on this thing is so basic looks to be nothing to it really. Then I was looking into the rearend an it has a solid axle with a dual clutch style center mount disc brake. The front disc brakes from a 74 Honda cb360 which ill use an refresh. Ill need a full twist throttle, any recommendations, id like one that has turn signals an light switches ect. I found only one.
Battery ill do last as some people recommend it build my own witch is sketchy for me. I was looking on battery places. I seen some car packs that are something like 22.5v and 6.5kw but are packs. How would you go with that route? They are 150$ each. Then I was looking at used Leaf batteries. Are they reliable when bought used?
Motor will still be a 40-45lb qs180
The kohler motor itself with the cvt style transmission, 10 gallon gas tank after removing that, it will lose roughly 200lbs or more as thats where all the weight is mostly.

The picture shows my gauges an the pull levers id like to use as a forward an reverse. But if the reverse on a qs180 isnt possible that way ill just use a spot on the gauge face to put a toggle to go in reverse an forward.
Theres another lever but ive no clue what it is.
 

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Found this because guy down the street is selling a '74 Rupp for $1250, complete but non-running and my first thought was, "Man that'd be a sweet electric conversion...". Curious if ya got further on this one?
 
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