Troubleshooting Currie 24V Lack of Oomph

[Nehmo]

I have a Currie setup, with a 450 watt brushed geared motor http://tncscooters.com/product.php?sku=106118 , the Currie 24V controller, and I’m using 2 12V group U1 tractor-mower lead-acid batteries.
It worked sort of okay, but recently after extensive use, it lost a portion of its power. I only seem to be getting about half the torque as usual, or another way of looking at it is that the battery becomes ineffective very soon after a charge. It currently works like it did previously when the batteries were almost dead.
I replaced the lead-acid batteries with new (yes, I realize I need Li-po; I’m working on that), and the new batteries V test normally. No improvement.
I suspected the motor. I opened it up. The brushes jumped out. (I was able to reinstall them by placing them back in position in their shafts, holding them with a loop of thread [dental floss would have been better], taping the two ends of the thread on the outside of the motor case, putting the motor back together, and then pulling out the threads.) Anyway, I didn’t see any obvious problems.
Now, I realize I’m supposed to transition to an entirely different setup, but just for the sake of solving problems for solutions sake, what’s wrong? Or what do I test next?

 

[wineboyrider]

This setup on 24v is not very oomphy anyways. I run mine on 36v, but I don't know if you can, because I have read somewhere on ES that the newer currie bikes and kits controllers don't have big enough caps. If you lost your license like I think I read on another post and you will be relying on electric bicycles as your primary transportation I highly recommend getting a BLDC kit now. BLDC motors will last a lot longer anyways. JMHO. I've been down the road you are going now so I'm just trying to help out.

 

[Nehmo]

I highly recommend getting a BLDC kit now.

That's a parallel endeavor.

I solve problems by making option lists. Then, if pursuing one option doesn't markedly interfere with another, I pursue as many options as possible.

For example, let's say female one is giving you lots of trouble, but it's possible to patch things up. And let's say there's another female who is a possible, but the situation requires attention. As long as there's no overlap temporally, you work on both.

 

[dogman dan]

A bush in the hand is better than two in the tree.

How did those brushes look? Sometimes a brushed motor just trashes it's brushes if it ever gets very hot. The rubbing end of the brushes may look porous, or even have chunks missing out of the edges. Possibly you just need new brushes.

Definitely a good entry level motor, but eventually you will want to spend as much as $1000-1200 to set up a bike that really can do a lot. 25 mph, 25 mile range at that speed. Generally that's a direct drive motor kit and a pretty large lithium battery. If 15-20 mph is your need, and the hills are not so steep, then less costly small planteary gear hubmotor and a smaller lithium battery can work well.

 

[friedwires]

maybe your batteries arent up to the task,lawn mower batteries arent really the best choice for powering an ebike. i would take a voltage reading under load.if the voltage drops more than a few volts under load,you could have a nice pair of doorstops.and a good reason to upgrade.

 

[blueb0ttle2]

Wait a minute... tractor-mower batteries? That's for running the starter motor on those, right? That's not a deep-discharge battery. One needs deep-discharge in an ev to get good range. The batteries for ezips are like this...

If you want more oomph, hook some more batteries in parallel or use larger deep-discharge batteries or... go to lithium. I'm probably doing that soon for my ezip anyway
I hope that helps.

BTW if you are still using the original spring-contact connectors on the rear rack, don't. I tended to have those break or get intermittent connections. Run some cables into the handy plastic battery cases and use Anderson connectors in between the pack and the controller, so you can have a reliable (yet easy to disconnect) connection.

 

[dogman dan]

Quite possible your old batteries were a proper type. Definitely your new batteries are not. You need the kind with thick lead plates, that can do a deeper discharge without damage.

Also quite possible you have both problems, a motor that got overheated toasting the brushes, and a poor battery choice. And it could be as simple as a crappy connection or a partially severed wire to the motor that is cutting down the wattage that reaches the motor. So check that stuff real good too.

 

[wineboyrider]

I don't think it's the brushes. At 24v that motor is pretty reliable. I toasted my brushes eventually after 2000 miles, but that was on 36volts!
Make sure you put it together right as it's tricky getting those brushes to seat properly.

 

[Nehmo]

Wait a minute... tractor-mower batteries?

The bike was running acceptably using a similar set of batteries; then, something happened to degrade performance.
I realize the batteries are not so-called deep cycle but they were cheap. And actually I doubt the lead-acids that Currie supplies are any better in terms of amp-hours.

The batteries test ok under load. The V doesn't drop appreciably.

Regarding the brushes, they seem to look normal, but I'm not sure what to look for. When I've opened other motors that needed brushes, it was obvious.

I'd change the brushes on GPs if I could get some quickly.

 

[vanilla ice]

If you overheat the magnets, it will give symptoms like what you are saying.

 

[amberwolf]

It worked sort of okay, but recently after extensive use, it lost a portion of its power. I only seem to be getting about half the torque as usual,
----
or another way of looking at it is that the battery becomes ineffective very soon after a charge. It currently works like it did previously when the batteries were almost dead.

These sound like two different symptoms. Do you mean that it *always* only gets half the torque it used to, or that this occurs after a very short time of use?

If the former, it is more likely to be a motor or controller (or connection) problem than a battery. If the latter, it is more likely a battery problem, but could be something overheating in motor or controller after a short time.

I replaced the lead-acid batteries with new (yes, I realize I need Li-po; I’m working on that), and the new batteries V test normally. No improvement.

So the problem does not change at all with a different set of batteries? Then it is unlikely to be batteries, unless the charger itself is simply not fully charging them anymore. Does the different set of batteries include trying a different charger?

I suspected the motor. I opened it up. The brushes jumped out. (I was able to reinstall them

It is possible that one or more windings in the motor itself have failed; you can test this by first looking at them for color differences. If there are none, then you can use a multimeter between each of the commutator segments (there are probably 16), and noting down the resistance between each. This will test for shorts and opens. Only the ones diametrically opposite from each other should have electrical continuity; all the others should be isolated from each other.

Anything other than a short circuit is too high a resistance, at least on the typical multimeter. If you have a very-low-range meter, you might be able to get notable readings for the windings, but they'll basically read zero or maybe 0.01 ohms with a typical meter.

That is probably a 4-brush (4-pole) motor, so two of the brushes are wired to negative, and two to positive, so it uses two windings at all times. If there is no "vibration" or pulsing in the power of the motor, it is unlikely that a single winding or set of them is at fault, but more likely that if the torque literally feels cut in half but the no-load speed is the same that one set of brushes is either not seating against the commutator properly, or is not getting power.

Some motors may have a thermal breaker inside them, in series with the brushes; I doubt yours does but if it does and has one for each set, and only one is popping, it would act as if half it's torque was taken away but still get the same speed.

 

[Nehmo]

These sound like two different symptoms. Do you mean that it *always* only gets half the torque it used to, or that this occurs after a very short time of use?

If the former, it is more likely to be a motor or controller (or connection) problem than a battery. If the latter, it is more likely a battery problem, but could be something overheating in motor or controller after a short time.

Always. I always get much less power than before the problem.

...
That is probably a 4-brush (4-pole) motor, so two of the brushes are wired to negative, and two to positive, so it uses two windings at all times. If there is no "vibration" or pulsing in the power of the motor, it is unlikely that a single winding or set of them is at fault, but more likely that if the torque literally feels cut in half but the no-load speed is the same that one set of brushes is either not seating against the commutator properly, or is not getting power.

Some motors may have a thermal breaker inside them, in series with the brushes; I doubt yours does but if it does and has one for each set, and only one is popping, it would act as if half it's torque was taken away but still get the same speed.

Yes, it has 4 brushes. The number on the motor is
MY1018JC-2
245080612027
which is different from the style number (Style: MY1018Z) in http://tncscooters.com/product.php?sku=106118
There wasn't anything that looked like a fuse or breaker in the motor. I tried getting a reading on the resistance of the winding, but wasn't successful. I'm going to try again. --- I'd like to get some brushes locally ---I have to post now. The connection is ending. I'll continue later.

 

[dumbass]

I would consider looking "outside the box". I have 4 EZip motors running right now and I think it's very unlikely to be a motor problem. If your 100% sure your batteries are good then start looking for simple things like dragging brakes and bad connections. You can test the hall voltage as well and output of the controller. You should be in the 4.5v to 5.0 voltage. Be sure your getting it in both direction and be careful not to short anything. Bob

 

[Nehmo]

I would consider looking "outside the box". I have 4 EZip motors running right now and I think it's very unlikely to be a motor problem. If your 100% sure your batteries are good then start looking for simple things like dragging brakes and bad connections. You can test the hall voltage as well and output of the controller. You should be in the 4.5v to 5.0 voltage. Be sure your getting it in both direction and be careful not to short anything. Bob

What should "be in the 4.5v to 5.0 voltage"?

The sensors by the bottom bracket are useless. The magnet disk came loose and I removed it. I never ran the bike in that mode (the mode where you're supposed to get assist according to how hard you pedal) anyway. But the problem didn't arise at that point.

I assume the controller is PWM. I'm not sure it's smoothed out before it leaves the controller. I'll test it anyway, but I don't have any normal results to gauge what I should be getting.

 

[zap]

I have the same motor in my trailer and like others have said, I doubt the problem is the motor. When you had the motor apart did you happen to look into the geared side to see if all was well in there?

Since it's a brushed motor... one way to test the motor would be to hook the batteries straight to the motor, bypassing the controller. Be very careful doing this.
You might want to try this with the driven wheel off the ground first. If you have a speedometer you could hook it up to the driven wheel and test it using the controller first then hooked straight to the batteries and see if the speed is any different. I'm going to assume the controller will drop a volt or two but I don't know how much it would actually drop it so maybe someone will chime in with that amount.
You could also try applying the brakes doing the same thing to try and test the amount of torque.

I think the "4.5v to 5v" that dumbass is referring to is the voltage that should be going to the throttle?

 

[dumbass]

Yes the voltage from the controller to the hall (throttle) should be 4.5 to 5.0v. IT should also have a simular reading from the hall (throttle) back to the controller but will very depending on the throttle position. The conector has 5 wires. 2 are for the colored lights and 1 is a ground, 1 is the output and the other is the return. Sorry I don't remember what color wire is witch.

The peddle assist has nothing to do with your problem. And I think your confused as to what it actually does on this bike. It is not controled by peddle pressure but by how fast you are peddling. And it will not cut in untill I think around 5MPH. Bottle line it's crap and your better off without it. I just disconnect it at the controller.

I'm not understanding your last question.

Zap is correct you can connect the motor directly to the battery without the controller. But you should try to get a feel for how it acts with the controller and the wheel off the ground first so you can compare it.

As Zap said you could be binding inside the gearbox but honestly I think it's a long shot.

Did you by chance tighten the motor chain? Some people have reported a huge power lose because they adjusted the motor chain to tight. This puts a major bind on the motor and freewheel bears which consumes a lot of the motors power. It will also cause the motor to overheat. This chain should have 1/8" to 1/4" of free travel in the center of the chain. Bob

 

[zap]

As Zap said you could be binding inside the gearbox but honestly I think it's a long shot.

I agree. For that gearbox to soak up "half the torque" it would probably be smoking hot.

Did you by chance tighten the motor chain?

This is a good point.
Actually... did you change anything on the bike? Did the bike take a fall or get knocked over? Did anything get wet?
There are a lot of variables here and we're, more or less, taking shots in the dark at what's wrong.

Woody is using a 24v controller from a Schwinn scooter upped to 36v. If I have the time today I'll try and redo it for 24v and see what kind of readings it puts out.

 

[Nehmo]

I would consider looking "outside the box". I have 4 EZip motors running right now and I think it's very unlikely to be a motor problem. If your 100% sure your batteries are good then start looking for simple things like dragging brakes and bad connections. You can test the hall voltage as well and output of the controller. You should be in the 4.5v to 5.0 voltage. Be sure your getting it in both direction and be careful not to short anything. Bob

I'm going to directly attach the motor to the batteries. It's only a regular brushed motor. I'll see what happens.

 

[Nehmo]

I would consider looking "outside the box". I have 4 EZip motors running right now and I think it's very unlikely to be a motor problem. If your 100% sure your batteries are good then start looking for simple things like dragging brakes and bad connections. You can test the hall voltage as well and output of the controller. You should be in the 4.5v to 5.0 voltage. Be sure your getting it in both direction and be careful not to short anything. Bob

I'm going to directly attach the motor to the batteries. It's only a regular brushed motor. I'll see what happens.

 

[Nehmo]

I would consider looking "outside the box". I have 4 EZip motors running right now and I think it's very unlikely to be a motor problem. If your 100% sure your batteries are good then start looking for simple things like dragging brakes and bad connections. You can test the hall voltage as well and output of the controller. You should be in the 4.5v to 5.0 voltage. Be sure your getting it in both direction and be careful not to short anything. Bob

I'm going to directly attach the motor to the batteries. It's only a regular brushed motor. I'll see what happens.

 

[Nehmo]

I would consider looking "outside the box". I have 4 EZip motors running right now and I think it's very unlikely to be a motor problem. If your 100% sure your batteries are good then start looking for simple things like dragging brakes and bad connections. You can test the hall voltage as well and output of the controller. You should be in the 4.5v to 5.0 voltage. Be sure your getting it in both direction and be careful not to short anything. Bob

I'm going to directly attach the motor to the batteries. It's only a regular brushed motor. I'll see what happens.

 

[Nehmo]

I avoided some detail for brevity, but the bike, within the limits of the primitive hardware, was doing okay. I used it all day every day (batteries lasting less distance with each recharge) until the batteries are cycled out. That is, until they don't hold enough of a charge to go very far. Lead-acid isn't a good choice for these kinds of cycles. Then I'd replace the batteries.
[skipping some more detail]
At one stage like this, I replaced both batteries and I didn't get the refreshed bike as a result. Something other than the batteries is bad.
I didn't wreck or change anything worth mentioning.
I just got an email back form Tncscooters. They don't sell brushes for the motor they sell and aren't sure those brushes would match my motor anyway. (The motors have different style numbers, mine is MY1018JC-2). But since they are willing to exchange email, I'm going to ask who makes those motors. I don't recognize the logo and haven't been able to find it on an image search. The triangle on the top label in the pic on http://tncscooters.com/product.php?sku=106118

Yes, I know. We have some repetition. But everything good in life is repetitious .

 

[dumbass]

Yes, I know. We have some repetition. But everything good in life is repetitious .

LOL, yeah, I guess. Ether way it's notworth worrying about.

FYI, even if you ordered a new motor directly from Currie and you/they would have no idea who's manufactured the motor you would receive. I have 4 "genuine" Currie motors that were ether came mounted on a new Ezip bike or were purchased directly from Currie. Except for different logos on the outside they all looked the same. But they all had suttle dIfferences under the hood. To replace the brushes you really need to compare them with what you are buying. I have seen brushes at my local Ace hardware store. Who knows maybe you'll get lucky. But you said the brushes looked good. Personally I do not think yOU ?have a brush problem though. But I'm no expert.

 

[Nehmo]

Directly connecting the 24 V batteries (through a switch and circuit breaker, 'course) works. Ergo, the problem is in the controller, the throttle (turning hand control; it's a misnomer calling the PWM creator a controller, but that's another subject), or the wiring.
I opened the box containing the smaller box containing the controller [The controller, oddly, is labeled “DC brushless motor controller, 35 A” (used, in this situation for a brushed motor).] and two smaller mystery boxes. I didn't see anything out of line. In fact, Currie redundantly used plastic ties around all the snap connectors.
Actually, I'm now riding the bike on a several-mile trip, I and an assortment of tools. (I stopped at a WiFi to post.) I left the seat off. The left peddle crank keeps coming off, and the bearing in the bottom bracket is sloppy. I still haven't put that trust washer back in the motor; I taped it on the outside. Some of the wires and switch I'm using are so small, they get hot. Some things in life must be delayed.

 

[dumbass]

Strange that the controller says brushless. I have heard of some controllers that can switch hit but not sure if it's true. maybe someone else knows. I confident that the 5 Currie controllers that have say "brushed". And none of my bikes have any other little boxes in the panel. Yeah, the do wire tie everything but think that's a good thing. Bob