I bought an EVT 4000e from a friend. It has worked well for the past 400 miles but now something is wrong. The other day when I was starting home from work, it started "missing". I turns out that only like 1/2 of the motor is pulling. When I take off, the bike goes "cunk, cunk, cunk, as the wheel rotates from power to no power and back to power. When I put it on the stand, it won't move the tire... when the power is on... unless I rotate the tire by hand to the "power cycle".
Any ideas? Electric Motorsports in Oakland can't look at the bike for 2 weeks or more.
Thanks,
Brian Souder
1st thing you could do is get the Manual from the Document site.
http://ilbcnu.org/file_share/evt_4000e_maintenance_manual_with_tools.pdf
You should check the following
1) wiring for loose connectors or battery bolts.
2) wiring from the controller to the motor for damage, or loose connectors
3) battery condition (4 batteries, one bad can make the whole scooter act weird)for this you will need a voltmeter. Doesn't have to be expensive. You want to check each battery for similiar voltages.
Robert Dudley
E-Scoot Tech
What you're making me think of is perhaps the innards of the motor aren't in good shape.
I wrote up the following page about cleaning an EVT hub motor. It shows how to open it up.
http://www.7gen.com/book/my-ev-projects/cleaning-evt-hub-motor/701
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
Robert,
You may be onto something. I put on a new tire a few weeks ago and noticed that the wires going into the hub motor were freyed. I put some tape around them but I am thinking that, if one of those wires were damaged, it might lead to this problem.
So, the $64,000 question, if the wire leading into the hub is damaged, can it be repaired? I haven't pulled apart the motor yet.
BrianS
David,
Your article on how to clean the motor is excellent. I have already read it a few times. The motor on my scooter was cleaned about 400 miles ago, just before I bought it.
Thanks for your suggestion.
BTW, if one of the leads going into the axle is damaged, do you think it could be repaired? I noticed when I had the rear wheel off the other day, the wires were frayed.
What are your thoughts?
BrianS
Update:
I got tired of waiting and decided to tear into my 4000e this past weekend to find out why 1/2 of the motor wasn't working. (The wheel would only pull through part of its rotation).
Well... here's what I found.
Notice that every other brush is almost completely gone. Why would that happen? Of course I will replace all of these but I just found this really odd and I am wondering why this would happen. Electric Motorsports replaced some (all?) of these brushes just 400 miles ago. Why would this happen?
Next, I noticed something. I don't know if this is right or not so please excuse my ignorance but are the positive and negative terminals supposed to cross like this? Can someone shed some light on how this should be wired up?
Lastly... does anyone know where I can get new brushes and cables and stuff? The old cable that leads into the motor through the axles had completely melted. I will have to build a new cable from scratch... or buy one.
Any help is greatly appreciated.
Thanks,
Brian Souder
Does Electricmotorsport offer any kind of warranty on their service? I would show that to them, and ask for replacement brushes, and also note that you are documenting the process on a popular web forum.
It is difficult to tell from the pictures if the brushes are worn completely, or the brush springs are the problem. Brush springs can be damaged by high heat. And, sometimes they don't produce enough pressure causing arcing and more heat. My bet would be that the springs are somehow related to the problem.
It is also possible that electricmotorsport didn't replace all of the brushes.
For new brushes I think electricmotorsport or EVT World would be your best bet. To build a new cable you'll need some wire of the same size which can be found at electronics suppliers, hardware stores, and auto parts stores. Also you'll need a soldering iron and preferably some heat shrink to cover the solder joints.
[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri
Electric Motorsport does carry the replacement brushes for this motor.
- David Herron, The Long Tail Pipe, davidherron.com, 7gen.com, What is Reiki
An update on my EVT4000e motor.
I spoke with the good folks at Electric Motorsports. They said every other brush failed because those are the brushes that carry the negative charge and that's where the heat builds up. I confirmed that the wiring is correctly. The motor most likely failed so quickly because it got too hot trying to haul me up the hill I live on.
Now my dilemma—should I…
a) Rebuild the existing motor (and probably burn it out again on my hill. Estimate: $200
b) Upgrade the scooter to the new and more capable brushless motor. Estimate: $800
c) Upgrade to new motor and 60 volt system for more power / speed. Estimate: $1400
I don’t mind upgrading if the bike will be more reliable when I am finished. Has anyone upgraded to this larger brushless motor? How will the rest of the bike (the controller for example) handle the 60v upgrade?
BTW: I need to stay with this style of scooter because I need to ride in the bike lane during my commute.
Any feedback is GREATLY appreciated!
Brian Souder
While the better brushless hub motor looks like the best option, the upfront cost is kind of high. It's probably the easiest, most efficient, and ultimately most practical option. It really depends on your goals. Here's what I personally would do though it would require a lot of work:
1. Sell the motor and controller
2. Buy one of these motors:
HXT 80-100-B 130Kv Brushless Outrunner (inspired by Reikimans post An interesting approach to electrifying a recumbent, I contacted Matt Shumaker, and he recommended this motor for lots of power)
At 130 rpm/v it could maybe be reduced with single stage reduction. A suitable scooter wheel with sprocket will need to be found. Probably a metric sprocket will need to be adapted, and this motor could be mounted to the swing arm. A Kelly brushless controller could probably be used (not sure on this, but if it doesn't it can be sold). Additionally, a contactor and some type of throttle control to provide the proper input to the controller would be needed.
Sounds like a lot of work, and it is. That's just what I would do. The payoff would be something else though. This would be going from 1500 watts continuous output to over 5,000 watts. And the monetary cost would be between $600 and $700 depending. Then once the stock lead batteries die, replace them with lithium and you'd have one heck of a commuter that could do over 50 mph for a considerable range.
[url=/forum-topic/motorcycles-and-large-scooters/587-my-kz750-electric-motorcycle-project]KZ750 Motorcycle Conversion[/url]
[url=/forum-topic/motorcycles-and-large-scooters/588-fixing-my-chinese-scooter]900 watt scooter[/url]
Pic from http://www.electri
Hi Brian
Sounds like option a) would be a little pointless as the chances are it would overheat again sooner or later.
Which leaves upgrading the motor. The Electric Motorsport website lists a 3kW version of the EVT hubmotor which presumably would slot straight in and use the existing controller. Have you spoken to them about this? It would probably cope with hills a bit better without overheating.
A brushless motor would be nice, but would require a new controller too. Also the throttle on EVTs is unusual so you'd probably have to change that as well.
(The Nova Scooters 3.5kW motor and controller kit sounds pretty good though and should be a fairly straightforward swap.)
My EVT is upgraded to 60v with the standard 2kW motor and controller. Performance is certainly improved from 48v and its given no problems at all. The bike has done 4000km, although most of those were at 48v. (There was a good thread about this conversion for a 4000e a while back).
But as you've had overheating problems with the standard EVT motor at 48v, then running it at 60v is probably not a good idea in your case. However, perhaps the 3kW EVT hob motor would work well at 60v and be strong enough to not overheat on the hills either. Be interesting to know if Electric Motorsport have tried this...
Whatever you decide, good luck!
I don't understand WHY your 1500w drive motor would "BURN OUT" going up a hill!!
a) On the dashboard is an OVERHEAT sensor etc.!!, which is SUPPOSE to be "functional"!!, and prevent serious motor overheating from occuring!
b) My evt4000e seemed to handle a 3-4 minute ride up a mid-size hill (in econmy mode,I weigh 208lbs) at steady state speed of about 18-20mph!!
c) The specs state: the evt-4000e SHOULD BE ABLE to navigate a 8 degree slope, at 10.5mph.
http://www.bravoelectricvehicles.com/bravo-evt-4000e.aspx
PERFORMANCE * MAX.SPEED 30 mph
CLIMBING 8% X 10.5 mph
----------------------
Just HOW LARGE was the hill you routinely tried to navigate?? And what was your approximate rider load?!
Vincent
----------------------
The hill... the steepest part is about an 18% slope.
As for the "overheat" sensor... it only came on one time the entire time I owned the scooter.
Since then, I bought an Oxygen Lepton... it is AWESOME. More power and, overall, a much more substantial scooter.
BrianS
PS: In hindsight... I am not in favor of the sealed, brushed motors from EVT. They are sealed... and are not designed to be user-serviced... which means you have to pay a lot of money for someone else to service it every 1000 miles. Brushless is the only way to go.