Transferring this discussion from "Test Ride of the ZEV Scooters," which became a mash-up of various ZEV topics. (I think ZEV deserves a folder here, like other brands.)
The problem: I'll be riding my ZEV S-8500 in any throttle position, then there's a complete loss of power (motor cuts out) until I zero the throttle for a second and twist again. Since this sometimes coincides with riding over a bump, I searched repeatedly for loose/faulty connections. But it doesn't seem to be a simple power interruption. When the bike is apt to do this, it starts rougher (hesitates a bit) from a stop, and there's a quiet growling or groaning sound, from the hub I think, especially when first accelerating. Other times when it accelerates smoothly and quietly, the cutting-out is rare or absent. I used to think a fresh charge made it run better, but that is no longer true. The scooter comes right off the (new) charger now, rides normally for a block or two, then starts cutting out like crazy, multiple times each block.
I bought the scooter from a guy who had it a year and put 600 miles on it. He reported no such problem, but I can't vouch for his honesty. It has a Cycle Analyst (not with throttle control) and an upgraded ZEV 180 amp controller, the former installed by ZEV and the latter by the owner. The included charger went dead in mid-August and I bought a new one, the latest model, from ZEV. Interesting factoid: The cutting out disappeared completely for over 2 weeks when I started using the new charger — I thought the problem was solved. Then for no apparent reason it returned. The new charger seems to work as designed, with an (initial) 12 amp bulk charge, then eventually top-balances with a fraction of an amp. The bike's resting voltage after this is about 101.5, but it immediately drops to about 96 as soon as I start to ride, and stays there. The Cycle Analyst shows no sudden voltage drop when it cuts out, and Vmin is in the mid-80s.
Here's what I tried so far without effect:
- Both brake micro-switches and the side-stand switch are disconnected.
- I repeatedly inspected, and shot with aerosol contact cleaner, all cable connections and small wire connectors behind the dashboard and under the seat, plus the 24-pin connector on the controller. All battery and circuit breaker connections are tight.
- I confirmed constant voltage from the key switch to the controller, including when I jiggle wires and bounce the bike up and down.
- With the bike running on the center stand, I was unable to make it cut out by handling/jiggling wires behind the dash or under the seat. Or the key in the key switch.
- On two separate occasions I measured all cell voltages when fully charged, and again after running the batteries down to where the controller stops the motor. Both times the fully charged cells were all close to 3.34. The first time I found two discharged cells with voltages around 2.8 as compared to about 3.1 for the rest. I charged them individually, bottom-balanced the pack, then fully charged as usual. The cutting out still happened. The 2nd time, all discharged cells were between 3.04 and 3.13. I didn't bother to bottom-balance, and just charged as usual. The cutting out was bad as ever.
Darus Zehrbach at ZEV walked me through most of this, and I sincerely thank him for trying to help. However, his simple/brief suggestions often result in hours of frustration for me. For example, it sounds easy to remove the plastic covering from the handlebars to trace the wires from the throttle, kill switch, etc. I twisted and squeezed and pried and swore until I finally started breaking off the plastic tabs on the covers, so I gave up. I also spent many hours several weeks ago removing the top row of batteries, unnecessarily it seems. There's apparently no wiring diagram or service manual, and I'm still fairly new to EVs, so nearly every step means either guessing or emailing Darus, or both. I'm hoping others here recognize these symptoms and can point me in the right direction. In particular, I think the only possible culprits I haven't checked/tested yet are the BMS and controller themselves. (And maybe the Hall sensor?) Are there any tests I can perform with a multimeter on these components? I assume swapping out controllers is expensive, I haven't really checked. Is there a bad ground wire I may have overlooked?
This has been incredibly frustrating, and I don't mind saying I very much regret the purchase. On the other hand, if I ever get it working reliably, this scooter would be just about perfect for my intended use. Thanks for your suggestions and insights.
When growling out of the hub motor is heard you must have a faulty contact in the 5- or 6-Pole connector coming from the hub motor. It should dependalbly power the three Hall Effect switches in the stator that tells the controller when to fire up which of the three phases and in which order. If either the Plus 5V or Ground connection is periodically lost you will have a complete motor cutout, and if just one of the three hall switch outputs gets interrupted you get power loss and growling/stuttering in the motor. So either the connector is at fault, or one or some of the wires have had their insulation rubbed through and there may be occasional shorts, or a cable is even broken inside the insulation. The cable comes out the motor axle, together with the three thicker phase cables. Follow that 5 or 6-lead wire until to you find the connector I am talkig about, and take a VERY close look at all that. Maybe you will find your gremlin there...
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
My ZEV turned out to be this kind of nightmare as well, but not with these particular symptoms. Chinese scooter parts are Chinese parts no matter who assembles them. Given the facts above, my thought is that you have a bad controller, because I don't think a bad connector would give those little warning clues in advance of cutting out as yours seems to do. Controllers don't usually do that either, of course, so your best (not easiest, though) option at this point would be to see if you can swap in another controller - after first checking that hall wire connector. Does your bike have the spare set of hall sensor leads?
MEroller, I like your idea about the Hall switches, as it explains all the symptoms. The ZEV hub motor has two sets, one is a spare. The leads/connector from the active one look fine, although I still need to inspect the wires more carefully for breaks or shorts, especially as they run under the batteries to the controller.
Soon after buying the scooter, I noticed the spare sensor wires were damaged. The insulation was worn away and several of the wires were broken. I didn't try to repair them, instead I isolated the cut ends with electrical tape so they wouldn't touch each other. I removed the tape for this pic:
Tonight I also discovered that this spare is already butt-spliced where it exits the wiring conduit from the motor. It looks neat enough to be from ZEV, not the prior owner:
I don't see how the unused/unpowered set of Hall switches could cause any problems, but I thought I'd mention it, just in case. Strange that one connector is spliced like this, though, isn't it? Maybe I'll repair those wires and try running with the spare. I also learned that I can test the Hall switches with a voltmeter, so I'll try that too.
LeftieBiker, thanks for your thoughts. Reading the long threads about your ZEV (and Zero) woes led me to post on this forum in the first place. Obviously, I hope my problem is the Hall sensor signal, not the controller. But I seem to be narrowing down to the few remaining components I've been unable to check/test yet. The controller and BMS are still "black boxes" as far as I'm concerned... I don't really know how they work or how to test them. Blindly swapping out parts isn't my style, but I may be stuck doing that... I'll keep you posted.
Here's a little follow-up. I was suspicious that the wires from the Hall sensor connector to the controller may be pinched under the upper battery box and the frame tube it rests on. This would explain why a bump in the road sometimes makes it cut out. So I re-routed those wires so nothing can pinch or stress them. I also continuity-tested them, but found no breaks... which doesn't mean there aren't any. I then repaired the wires for the spare Hall sensor (see the 1st pic above), and tested that sensor using my multimeter to read dc volts. Checked out ok: the sensor receives constant power via the red and black leads, and each of the 3 outputs (blue, green, yellow) switched on and off as I turned the rear wheel. I took a short test ride, maybe a mile, over bumps and hills that normally make it cut out quickly. While the motor didn't sound perfectly smooth, it was "almost" perfect, and it cut out only once, over a big bump (San Francisco streets are in surprisingly poor shape, with lots of rails and similar).
I consider this a big improvement. It makes me think the Hall sensor or its connection to the controller has been the problem. Maybe it helped to free the wires from under the batteries, or maybe it was my switching to the "spare" sensor. Of course, I've been wrong before: the new charger "fixed" the problem for 2 weeks, then it didn't. My 15 miles or so on Mondays is a much better test, so I'll let you know.
[Edit: 10 hours later] Yep, too optimistic as usual. It cut out 5 or 6 times on my 4 mile ride to work. This is less bad than it's been lately, but still not good. Seemed less related this morning to going over bumps in the road, more when taking off from a stop. Much less likely at constant speed. Anyway, my gut tells me I'm on the right track; I'll dig back into the inputs to the controller when I have a spare hour or two.
This bike was acquired used, right? I suspect the first owner had similar issues, and tried to repair wires in the same manner you did, eventually switching hall sensor wire sets. If so, that suggests something worse than one bad wire.
Well, Leftie, you may be right.
As I was saying, it cut out 5 or 6 times on the way to work yesterday. Then only once on my afternoon ride of about 4 miles. As usual, I can't explain why it cut out in the morning, but (almost) didn't on a very similar ride only a few hours later. Finally, my 5 mile ride back home in the evening was "the best of times and the worst of times." No cutting out at all for several miles — I was actually enjoying silently zipping along a major city street at 40+ mph, thinking my scooter problems weren't so bad. Then suddenly it started cutting out like crazy, maybe the worst ever. I could hardly go 10 feet before the motor died again. This had nothing to do with bumps in the road, and it seems to me that an open wire would make the bike not function at all, not this "power-up-and-die" thing over and over. I had to use the emergency flashers (handy accessory for this scooter...) and inch home the last couple miles in the bicycle lane.
Once I got it in my garage last night, I put it on the charger. Didn't touch any wiring or even look under the seat. Tonight after work I unplugged it and took a mile ride. It worked without any cutting out. I can't explain how simply charging a bike would remedy a wiring (or Hall sensor) issue. Given that I twice tested the batteries, maybe the problem is the controller after all. I'm running out of alternatives. Should I get online and shop for e-scooter controllers, something I know nothing about? Or buy (another) one from ZEV? The phrase "good money after bad" is ringing in my ears...
I agree that the behavior isn't that suggestive of a bad wire. The problem is that we still haven't narrowed it down to one component. It could be a bad pack, or a bad controller, or maybe even still bad hall sensors that behave better at the bike's highest voltage than at lower voltages, although I don't see how that would work...
This vaguely reminds me of a seemingly unrelated anecdote: I was about half as old as I am now, and my father had bought a running but rusty Volvo P1800E, just for the good nose on it, which he planned to transplant into his 1800E. I convinced him to instead sell me the car for what he had paid for it, and it was a great running car - until I washed the engine compartment. I knew how to do it safely, but the car just wouldn't restart, and had to be towed from the car wash to the shop of an older, experienced mechanic. Against all odds he found the problem: the ignition primary wire had broken inside the insulation, with no external sign of failure. Talk about a needle in a haystack...
I believe I isolated the problem... to the controller unfortunately. I took it out for about 5 miles today, and as usual it started cutting out during the 2nd half of the trip. When I got home, I put it on the center stand, clamped pliers on the throttle to keep it running (slowly), then wiggled wires and connectors trying to make it cut out.
Wiggling stuff didn't do it, but knocking on the side of the controller did. Pretty reliably, in fact. I was also getting the initial hesitation, like the motor doesn't know whether to go forward or backward.
Here's a video, about a minute and a half, of the rear wheel of my scoot as I slowly twist the throttle. On the 1st attempt, it runs backwards, without my touching the forward/reverse switch, and I cut the throttle. On all other attempts, the motor dies either quickly by itself, or after it spins up and I gently bump the side of the controller with my knee while holding the throttle constant.
ZEV S-8500 motor cutting out
Although Darus advised me not to disassemble the controller, I think my next step is to unscrew the end plate in hope of finding a loose connection inside. However... (1) It's still remotely possible that knocking on the side of the controller is vibrating a wire attached to it, and not the controller itself, and (2) I still don't see how charging the batteries — or letting the bike rest a while, which may be the real issue — can affect this. But it seems to.
[edited to add video]
Yes, the controller seems to be guessing at every start in which direction to turn the motor, there is too much hesitation and growling - EVERY time! It still could be one of the hall inputs to the controller that is acting up, either at the connector or inside the controller.
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
It's not so easy to get into the guts of the controller. Unlike the smaller controllers for e-bicycles shown on YouTube, this one is filled with a hardened glue or resin, to fight vibration I assume. Unscrewing the end caps had no effect. To gain access, I removed the controller from the bike, then removed the 8 small screws on the backplate. Then you see this:
There are no visible broken wires, worn insulation, or burned/melted components. If anything's broken it's where I can't see or reach it.
The 3 intact metal sides of the controller are heatsinks and don't seem to come apart. The ends stay stuck even without their 4 screws each, and there are cables or wires running through them. I might be able to pull off the end with the big cables without destroying anything, but I still won't be able to see anything with the glue/resin in there. And if I dig out the resin I'm likely to break something. Unless anyone here has another suggestion, I'll contact ZEV about repairing/replacing the controller.
By the way, I discovered "brushless motor controller testers" for sale on Ebay for about $15, from China. Although they're made for lower voltage controllers, I imagine one could be useful for troubleshooting a problem like this. I might order one myself, just for kicks.
Look closely at those capacitors, to check for signs of bulging and/or discoloration. The photo isn't high enough resolution to see from that. Check EVERYTHING you can see for subtle things like browning...
I'm almost afraid to say it, but I may have fixed the problem. In the photo of the controller above, in the middle of the pic there is a small bundle of multicolor wires that terminate in a white connector. Here is an enlargement:
You can see that the black (ground?) wire on the left has an exposed solder joint, and the end of the wire sticks into the insulation of the capacitor. I thought (1) it could be a bad solder connection, and (2) the wire could be shorting against the outside of the capacitor. (#2 shouldn't be a problem if the outside of the cap is the ground, but I don't know enough electronics to say.) So yesterday I bent the end of the wire down, away from the capacitor, and re-soldered it. I then took the scooter on a 7 mile ride, and it didn't cut out even once. And today I rode it to work, about 10 miles round-trip. Again not one cut-out. :-)
If this indeed fixed the problem, it explains why it was so hard to diagnose. The cutting out acted like a loose connection, which it was, but it could not be found in the exposed wiring. It's also apparently part of the Hall sensor circuitry, accounting for the motor grinding and hesitating.
If the cutting out is gone, my only remaining complaint with this ZEV S-8500 is the suspension: it's an awfully rough ride over the potholes, transit rails, and asphalt patches here in the city. No wonder things shake loose. And aside from the suspension, that's gotta be rough on a hub motor. But on smooth pavement it's a magic carpet ride...
Yes, that could indeed have been your problem's root cause. The magic of Chinese soldering quality...
My rides:
2017 Zero S ZF6.5 11kW, erider Thunder 5kW
Great diagnostic catch! Maybe that ground wire against the capacitor barrel was physically pushing it and making an open circuit in the capacitor's connection? If it starts up again, try re-soldering the capacitor in place, or replacing it with a new one. As for the ride, did you loosen the pre-load ring on the rear shocks to get minimum preload? If the back springs are too tight, then between that and the Chinese shock's modest damping ability, you'd get a pretty rough ride.
There was very little adjustment I could make to the shocks to decrease preload, maybe 1/16". I may look for lighter springs, or maybe better shocks overall. And I need to weatherstrip (?) the trunk, as the lid rattles a lot. Darus Zehrbach at ZEV told me the suspension is set for a rider plus passenger. So a single (lighter) rider on rough roads gets a harsh ride. I understand the compromises, but it's a pity there's no way to adjust it in the direction I need — there's lots of adjustment available to increase preload.
All this is pretty minor compared to the fact that it doesn't cut out anymore. (Hasn't cut out once since I re-soldered that wire.) It was basically unusable before, and now I'm riding it daily. It bounces and bumps and rattles — I'm always concerned something will shake loose or break — but it gets me around. We have unusually bad roads here, can't blame ZEV for that. On smooth pavement it's really a pleasure.
It probably isn't worth putting new springs on a Chinese shock, so I'd look for decent aftermarket shocks.
I'm as bit late to the conversation, but I'm glad it was that connector - becasue with the whole controller board encased in potting resin, the controller is otherwise unrepairable. And the mass and differential thermal properties of such a large mass of potting can cause problems break solder joints. A "waterproof" Kelly controller I had on my scooter was potted solid. It lasted until the scooter hit the first bump. It was sent back and replaced with a "non waterproof" version.
I have a 2015 ZEV LRC 15 I bought used with low mileage. The front suspension was very stiff. I loosened the axle nut and the forks spread apart an eight of an inch. Very common on Chinese bikes. I shimmed it so the forks were parallel and it was better. Then I put in 5 weight fork oil. Better but still sticky so I installed used Honda Reflex forks I got on eBay. Had to use two left forks and fabricate some simple brackets so I could mount the dual calipers and fender. It was a bit of a project but the improvement was worth it. Also the front wheel was not centered so it pulled to one side when braking so fixed that at the same time. The rear suspension is ok but I have had other Chinese bikes with horrible rear shocks. You can usually find used shocks on eBay off a Taiwan bike like a Kymco or SYM that will fit and they are MUCH better. Hope this helps.
Hi. A little follow-up, after about 2 years...
The bad connection in the controller was the problem, and the scooter hasn't cut out even once since. I have almost 5k miles now, all in very hilly San Francisco, with remarkably bad roads. I have no further complaints about the drive train: it's a zippy little ride and I run it pretty aggressively.
I swapped the factory trunk for a used Givi from Craigslist, which rattles less. I never replaced the shocks or springs. They don't bother me anymore. Either they loosened up, or I learned not to worry about it. I ride with the low-beams on all the time, for safety.
My problem lately is brakes. The front has no stopping power whatsoever, and I can't figure out why. Plenty of pad, I flushed/bled the fluid once myself and once at a shop. Nothing's leaking, and the calipers seem to squeeze normally when off the bike. I'm thinking to try one of those aftermarket master-cylinder rebuild kits for about $20, although I have no reason to suspect it's faulty. Meanwhile, since I've only been using the rear brake, it's totally worn out. I can't find exact replacements for the pads, and of course no one knows the specs for a ZEV. There are thousands of pads on sites like Dennis Kirk and Revzilla. Does anyone here know what fits?
To be honest, Erik Buell's planned e-cycle, the Fuell Flow, caught my attention. Slated for release late next year, that may be my next ride...
It sounds to me like one or more bad cells. I know you measured the cell voltage, and found two low cells that seemed to get fixed by an EQ charge, but maybe they are still weak, dropping voltage severely only under load, and thus triggering the Low Voltage Cutoff briefly....
(This was in reply to a post that I now don't see. Strange...)
Maybe a false lead, but my X-Treme XM-3000 had what appeared to be identical calipers, but with smaller rotors than my ZEV.
Admin won't let me start a new thread, so........
A cut and paste from YouTube:
Leftie Biker
1 day ago
Lone Browncoat. The shipping company paid up. Darus took the money and sent me back a glitchy bike that died before 2300 miles. Zero is equally bad. There are several new scooters out that look good. Don't get a Zev.
Lone Browncoat
Lone Browncoat
22 hours ago (edited)
@Leftie Biker .....but I was excited by the development of range extenders or what I call APUs; auxiliary power units. Darus sent pictures of the ones on the one and two ton truck model trikes and the bikes will get 27cc versions by the end of the year. I would like to see a comparison of models sold and happy riders vs. bad examples. The one example in the forum, the owner found a ground rubbing against the can [negative] portion of a capacitor. In an update the man said he hasn't had a cutout/stoppage since. You just have to be willing to dig through a diagnosis with electrical problems. Its either a short or missing a complete circuit. Like on that damn G5 of mine. I thought I was going to have to buy a new engine control module, but the problem was no ground. So instead of 1500CDN, it cost me 332CDN and most of that was labour plus towing to my fav garage, then to a GM dealer (another 100 total) because only they can program the damn things. Then there are other things, like the starter motor. I just want to get away from all those engine breakdowns, fluid changes etc. As a computer builder since 1980 I can DIY myself electrical problems. Have been hacking the daytime running lights on bikes since 1978, so I can shut them off, but the bloody G5 is too complicated and inaccessible for a simple hack and controlled automatically, so I have no choice, which pisses me off. On disability, I can't afford anything put out by Detroit-Windsor...Oakville-Oshawa or wherever GM builds their crap, so the T3 pickup is my best choice [or maybe the 5D]. I don't want to be a shut-in or housebound, it would drive me right around the bend. Where I'm dismayed is that the trikes so far aren't as fast as the bikes. I need to go 62.5 mph or 100km/hr max.
Now I've read that there are no service manuals available, wonder if its different for the truck-trikes, because it is their meat & potatoes business, the bikes are a sideline, they thought they could fill the demand cheaper than BMW or Zero. I'm going to copy & paste this into the forum tomorrow anyhow. I noticed its not too active. Not many new posts.
Similar to my MDP-130 MyHD tuner/capture card forum over at the AVScience boards.