Overvolting 48V Crystalyte 4840 Hub to 72V

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VRdublove
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Overvolting 48V Crystalyte 4840 Hub to 72V

Hey everyone,

I'm working on building an E-bike out of a 20" Trek 850 cro-moly mountain bike. I decided to go with the 4840 Front Crystalyte hub motor.

I am going to buy this Crystalyte controller: 40A(36V-72V) X-5 Controller [CTAL-403672].

I plan on using 6 of these batteries until I can afford a LiFePO4 setup: Universal UB12180 . Are the universal AGM batteries decent?

Will the hub motor be ok at 72 volts? Will I need to replace the throttle module as well? What is an affordable charger that will do the job? I was thinking I could use three 24V chargers or six 12V chargers, I just don't know who has the best ones for the best price. They don't necessarily have to be super fast, just safe.

Sorry for the barrage of questions, I'm exciting to get this thing rolling..

LinkOfHyrule
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

It should be a blast on 72V. There are a few over on Endless-Sphere that have done it.

FYI, that controller won't work with the 4-X motors. They are brushed, while the X-5 is brushless. You need a brushed controller.

Luckily for you, they're cheaper than brushless ones. However, finding one that will work on 72V might be a problem. I know Kelly makes a 72V 200A programmable controller, but I don't know how much they are.

I don't really know of any 72V chargers that are particularly cheap. I haven't really scrounged around for them much, though, so take that with a grain of salt.

If you go with bank charging (six 12V chargers), you get the benefit of always having the batteries in balance. Shop around and you'll probably find something you like.

The Vector chargers work pretty well. I have a 2/4/6A charger that cost me like $30 including shipping, so you'd be looking at around $150 (shipping is cheaper for multiple items) for a set of 6.

EDIT: Uh, you got torque arms, right? A front C-lyte will demolish the front drops if you don't. I mean, you're looking at like 40mph top speed here.

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai

chas_stevenson
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

I have used the Universal AGM batteries and was not impressed. The GPS Scooter batteries from Gruber cost less and they preformed better than my Universal batteries did. Both of these batteries are what I would consider low end batteries. The batteries I prefer are B&B batteries found at Electric Rider.

Chas S.

VRdublove
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

So will upping it from 48v to 72v just add top speed, or will it add torque as well?

That controller definitely won't work? It says on there that it will work with 400 series motors as well. Would this AXE 4834 controller work? ...cgi.ebay.com/ws/eBayISAPI.dll...

If not, will any AXE controller work?

Will I need to upgrade the throttle to handle the extra voltage?

Do you guys know if the Crystalyte kit comes with torque arms? I am using a rigid steel fork so I doubt I will have any problems.

Thanks for the help already! this seems like a good community on here

-Tommy

Bringing High-Performance Electric Trikes to the People!!

www.FFRtrikes.com

LinkOfHyrule
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

Even steel won't be strong enough for that kind of torque. Trust me, you NEED torque arms on a front hub. It's reccommended at 36V, and pretty much mandatory above that. At 72V, you'd need them even if it was a rear hub.

I don't know if the C-lytes come with torque arms. I know most of the guys on Endless-Sphere make their own, so I don't think they do.

You should see an increase in torque and top speed.

I'm pretty sure that controller won't work, since that motor is brushed (as far as I can tell). Can someone cite me on this, plz?

Geeze, an Alltrax? Can you say, "overkill"? That sucker will work, and you should be able to out acellerate a friggin' Corvette. But you'll have to tone down the current in order to avoid stressing your motor and batteries. Unfortunately, that can't be done with the non-programmeable Alltrax's. A programmeable one will work fine, but is a little pricey.

That particular controller won't work (only 48V), but a 72V Alltrax will.

If you do go with an Alltrax, you may have to get a resistive throttle. I don't know if Alltrax's will work will hall-sensor throttles.

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CGameProgrammer
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

LinkOfHyrule is completely wrong regarding the controller -- the one you linked, VRdublove, is correct. However, there were some problems with some of them where the insulation around the FET screws would fail to prevent a short under high power. A number of people on endless-sphere upgraded their controllers with better insulation around the screws and better FETs (the stock ones are fairly high-resistance and of dubious quality). That said, there is a newer revision that fixes both problems, but I don't know which version poweride is selling.

The motor can definitely handle far more than 72V 40A, but the bearings don't seem to like it when you put many heavy lead-acid batteries over the rear axle. I once ran with 72V 12Ah which weighed 55 lbs and the motor would get hot around the axle after a ride, which affected nothing in the short-term but is not good.

Hyrule is correct in that you do NEED a torque arm if you're using a front hub motor. With just 48V 40A, I destroyed a front fork AND the motor itself by not using one, and I'd only gone on one short slow trip. Thread:

D'oh! Just destroyed my Crystalyte motor... and my bike

Scrolling down, you can see a photo of the torque arm that electricrider ships with their kits -- but I couldn't use it because the dropouts of my fork were not vertical. Afterwards, I bought a fork with a proper vertical dropout so I could use the torque arm, and the torque arm worked very well; I never had problems after that.

They sell the torque arm for $20 on this page: http://electricrider.com/crystalyte/parts.htm
I recommend buying two and using both; one on each side.

For throttles, you need one that does NOT have an LED battery status indicator. The LEDs are voltage-specific and too much will cause a short, destroying the controller.

EDIT: There seems to be confusion on what motor you're talking about. I assume you'll be using the X5, correct? There's no such thing as a 4840 motor. There are four versions of the X5: 5302, 5303, 5304, and 5305. The middle two are the most common by far. For a 20" wheel, I definitely recommend the 5303 or "Phoenix Racer" as electricrider calls it.

Bander
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

Tommy-
How are you liking the Trek 850 so far? I found someone selling one on Craigslist in my area for $100, so I'm going to check it out tomorrow and will probably get it. I hear their frames are pretty strong.

VRdublove
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

I love the ol' 830. It has been through hell and back and has given me virtually no problems. It was my first "real" mountainbike and still rides great 10 years later. The chromoly frames on these are pretty darn strong. I have actually decided to custom mount an etek on mine instead of going the hub motor route: http://visforvoltage.org/forum/3111-wiring-brushless-etek-cable-guage

I say go for it, you can't go wrong for $100. Good luck!

-Tommy

Bringing High-Performance Electric Trikes to the People!!

www.FFRtrikes.com

rooster
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

The figures 4840 refer to the controller for the 5303, etc., motor

rooster

LinkOfHyrule
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

LinkOfHyrule is completely wrong regarding the controller -- the one you linked, VRdublove, is correct.

EDIT: There seems to be confusion on what motor you're talking about. I assume you'll be using the X5, correct? There's no such thing as a 4840 motor. There are four versions of the X5: 5302, 5303, 5304, and 5305. The middle two are the most common by far. For a 20" wheel, I definitely recommend the 5303 or "Phoenix Racer" as electricrider calls it.

That explains that. :p

+1 on the 5303. That's a good match for a 20".

For throttles, you need one that does NOT have an LED battery status indicator. The LEDs are voltage-specific and too much will cause a short, destroying the controller.

Ones with voltage indicators are fine. I have one for 36V that's being run at 48V. Just leave the extra (usually blue) wire out. Three wire controllers won't even accept it anyway.

Also: The half twist ones at electricrider are way too expensive. You can get the exact same ones from TNC Scooters for like $15.

*oogles at the 5305 in the 20" wheel*

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai

cerewa
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Re: Overvolting 48V Crystalyte 4840 Hub to 72V

FYI, for 4840 and similar designations starting with "48" or "36", the first two digits are the intended voltage of a kit.

Crystalyte makes brushless motors in the 5xxx series and 40x series, these refer to the actual motor. The last 1 or 2 digits in these designations are the number of turns of wire around each iron pole in the motor.

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