should E bike,s have a diagnostic test system

[rog_london]

I've been an engineer all my life, and what I dread most of all is the enthusiastic but uninformed tinkerer who sheepishly brings me something to 'have a look at' after they've had a go at it and made the original problem ten times worse.

I don't need a circuit diagram, or diagnostics, to figure out what could possibly be wrong with an e-bike. There's nothing to it IF you have the necessary skills. List the possibilities on a standard hub-motor bike:

(1) Main electrical circuit from the battery
(2) The controller
(3) The brake levers
(4) The motor
(5) The pedelec sensor (if fitted)
(6) The throttle (if fitted)

Sub-divide the motor:
(a) Three motor windings
(b) Three (usually) Hall effect sensors - if fitted at all

What can be added? Well, years of experience and detailed knowledge of the operating principles. It's beyond me to teach someone that in any reasonable time scale. In any case, most of them aren't even remotely interested - they're just hoping they've found a likely mug who will deal with their problem while they do something more rewarding.

Trust me, 'Mr. Average' is usually a bloody nuisance!

Rog.

 

[flecc]

Trust me, 'Mr. Average' is usually a bloody nuisance!

Tell me about it! My first introduction to the "amateur fiddler" phenomenon was as a youngster in the cycle trade. The most common situation was someone bringing in a rear wheel with all the Sturmey Archer hub gear innards in pieces, asking us to put it back together. The usual excuse for this was priceless, "I started the job but haven't the time to finish it". It was amazing how often those hub gears made time vanish!

 

[mike killay]

Following on what Rog London says, if instead of trying to understand each and every little part on an e-bike, if you treat each part of the system as a whole and replace where necessary, then complicated diagnostics are not really needed.
The expensive bits are the battery and motor and it is these that seem to cause most anguish.If you have the money, they are easily replaced, provided that you are certain that that is what is wrong, and here is the rub because it is not so easy to decide which is at fault. Circuit diagrams with the expected readings will help a lot.
As for repairs, personally, I would only replace, there is no way that I would open a battery to fiddle with the cells, or a motor to check the windings etc.
Perhaps one day we may have an exchange system as we used to have with motor cycles and outboard motors. You take in your faulty part, they give you a repaired one at a modest cost.

 

[lessped]

Not mentioning names, there are one or two on here! Some of the requests for 'help' can only reasonably be answered by saying 'Don't touch anything. Go straight to your dealer'. E-bike electrics can be seriously dangerous in unskilled hands, or more specifically, the batteries can. A fire or an explosion can be close by if an unprotected short circuit occurs. Indeed, the systems are all low voltage - but with an almost unlimited current available, just as in a car, you could burn out the whole electrical system and have a fire on your hands - possibly in your hallway.

That's apart from the daft and comical but still dangerous things that can happen - like sudden full power when you're tinkering and not expecting it, and certainly not aboard the bike.

Rog.

That just about sums me up

 

[Dreamer]

Think i will pull out this thread keeps going back and forth with regards to me helping someone with a battery.

Maybe best to pm next time Rog if you don't agree with something said or done than bring it up in public.

Bringing it up in this thread to me has degraded what could have been a good discussion.

 

[rog_london]

Sorry you feel like that! It wasn't meant to be personal. I genuinely worry about those who don't understand the risks. Diagrams and users' guides can certainly be helpful, but they're no substitute for experience. Purely my opinion, of course!

And I'm all for a good discussion - maybe you give up too easily.

Rog.

 

[flecc]

Think i will pull out this thread keeps going back and forth with regards to me helping someone with a battery.

Maybe best to pm next time Rog if you don't agree with something said or done than bring it up in public.

Bringing it up in this thread to me has degraded what could have been a good discussion.

Sorry you feel like that! It wasn't meant to be personal. I genuinely worry about those who don't understand the risks. Diagrams and users' guides can certainly be helpful, but they're no substitute for experience. Purely my opinion, of course!

And I'm all for a good discussion - maybe you give up too easily.

Rog.

Difficult balance isn't it.

There's "chuck 'em in at the deep end", "health and safety precautionary" and "nanny state" alternatives, all with something to be said for them. We all have different ideas on this, personally I fall just below the "chuck 'em in" point, giving all the details but with a warning where there could be risk.

 

[rog_london]

How right you are, Flecc. Of course, there's also the entertainment element, and I wouldn't really want anyone to take me too seriously. Come to think of it, it wasn't Dreamer who started the thread, and I didn't have anyone in particular in mind.

I know - you've been there too!

Rog

 

[neptune]

Over the years much of what I have learned has been from books. Some people can learn from books, and some can not. A problem with many books is that they do not start from step one. I have met guys who have passed the Amateur Radio Theory examination , but given a battery, a bulb and some wire, could not make the bulb light. As with all learning, we need to grasp the simple before we worry about the advanced. In its most basic form, an electric bike consists of a bike, a battery, a motor and a switch. That is all that is essential to make it work. Then we add the fancy stuff like a controller, pedalec sensor, brake cut outs, and throttle. Unless we have a dedicated controller tester, the controller is the hardest part to fault find. We can, in a sense , test it by default, if we can prove all other parts are OK, including the wiring, the problem has to be the controller. The moral is, to learn the basics first.

 

[rog_london]

I definitely go along with that. If you can use a multimeter you're in with a very good chance - but with no background knowledge at all, it's a difficult task, and it's ever so easy to make a wrong assumption which might make matters worse.

The psychology of fault finding is curious - in general, I've noticed that people tend to blame the part they can't fix. In the case of an e-bike, the controller usually gets the blame. Actually, there are numerous tricks you can try to eliminate the obvious. Take the motor, for example. If you disconnect the winding wires (of which there will usually be three or four, depending on whether it's a delta or wye configuration) you can put your voltmeter across any winding on a suitable AC range, rotate the wheel backwards - and you should get a voltage generated by the motor. Why is that? Because you defeat the freewheel by rotating the wheel backwards and you spin the motor, which acts like a generator. It has windings, and permanent magnets, and so is an alternator just like any other. You don't usually drive it that way, but it works nevertheless. If you don't have a voltmeter to hand, a small automotive bulb will let you do the same thing - the bulb will light up. So, you can check out the motor windings and the internal gears with almost nothing in the way of tools.

On a bike with the 'traffic lights' on the handlebar - switch off the power, and just wheel the bike backwards. Does the red LED glow? That shows the motor is generating power. It's only an indication, but, as the man from Tesco might say, 'every little helps'

That doesn't help you with the Hall effect sensors - you'll need a meter for those.

If nothing seems to be working at all, if everything is connected and you have power to the controller, your voltmeter on the power wires to the motor will give a kick as soon as the controller wants to apply drive. This will happen even if the Hall effect sensors are disconnected - because the controller has to move the wheel before it can get any signal from those sensors.

You might - or might not - realize that the motor drive wires are thick (they carry a lot of current), but the Hall effect sensor wires are thin! You don't need a wiring diagram for that.

I'm not necessarily suggesting any of you do any of this - it's just an illustration of what you might try if you understand the fundamentals.

Rog.

 

[donkeydoo]

In life you learn from your mistakes and hopefully listen to people who have made mistakes but are prepared to share their experience to stop you making the same mistake. Simple thats why we are here on the forums. Knowledge is key and sharing it too.

 

[neptune]

@rog_london. Until health problems forced my retirement two years ago, I ran a small successful business repairing washing machines. Many of the problems I faced were very similar to repairing Ebikes. Wiring diagrams and specific information like fault codes were very hard to come by . I had no formal training in the trade, but had some basic theory, having served my apprenticeship as a Telecommunication Technician back in the 1960s. I also knew how to use a multimeter. In later years we had a Website for independent engineers where we would share information and fault codes.

I believe that the psychology of fault finding is very important . Experience teaches us to use a logical thought process. It is all too easy to jump to false conclusions. For a start, I found that more than 50% of washing machine faults are not electrical. Then there is the 80-20 rule. You can cure 80% of the faults in 20% of the time, and vice versa. If you spend ages on a fault, and learn the hard way, you never forget . One I shall always remember is, the customer moves to a new house, and takes the washing machine with them . When they come to use it, it will not pump the water out. The first time I had this it took me ages to find the fault. When the house was built and the plumber fitted the U bend under the sink, there is a spigot , or stub pipe to fit the washing machine waste hose on to . The plumber always blocks this off with a blanking plug in case the customer wants to use the sink without installing the washing machine. Before I discovered this , I had taken the machine back to my workshop twice, where it worked perfectly of course. There is ultimately no substitute for experience, and no shortcut to aquiring it. But we all have to start somewhere.

 

[Dreamer]

"Not mentioning names, there are one or two on here!" sort of personalizes it a bit? not mentioning names leaves the back door open a bit."Don't be sorry" us scots have thick skin. Think its to do with the weather.

True i never started the post but I didn't drive it off co**** either.

Just don't like good threads getting driven off topic. Nothing worse than going into a thread and seeing it has been driven off co**** like this one which has now got half posts on topic and half off. Though what is good with this one is it has went to more useful info. good post on motor check btw. Maybe you should add how to test the halls sensors.

Maybe one of you guys with more knowledge on batteries should put a post up on safety/checking/etc if you feel you have genuine concern.

Me pulling out of it was to try get it back on track.

On the entertainment side just had a good giggle with the thread on 9000W. "Spill you Ovaltine" couldn't help but laugh.

 

[Dreamer]

oops think my mistake in spelling has given me some stars.

Was always more into maths and physics than english.

Reminds me of a Plato quote.

"Knowledge which is acquired under compulsion has no hold on the mind. Therefore do not use compulsion, but let early education be rather a sort of amusement; this will better enable you to find out the natural bent of the child."

 

[flecc]

Maybe you should add how to test the halls sensors.

Posted by member Andrew Harvey previously:

"To test the Hall sensors on in the motor is more tricky, you have to apply a voltage to the thin red and black motor cables, a small 3 to 9 Volt battery pack is ideal, positive to the red, negative to the black, then with a multi meter set to low volts DC measure the voltage between the positive supply and the hall sensor return cables, then with your third hand spin the wheel. So if you start with say the green hall sensor cable connected to the meter, you should see a voltage between 1v and the voltage of your battery, turn the wheel, this voltage should change as the wheel moves, going from a low voltage to a high. Repeat this with the other sensor cables.
If your wheel is geared with a freewheel turn it backwards."

 

[shemozzle999]

Hi Dreamer,
I can assure you my post which you objected to had nothing to do with the other thread to which you refer.
I was airing my opinion on Neptune’s post regarding the release of detailed service information into the public domain.
I did not think it would be a good idea because I was worried about the safety aspect of such an action.
However I do think it is a good idea to provide visual indications of the operation of the system and offered a suggestion as to how it could be increased.
Regarding the safety of e-bikes, like all systems I have worked on I have great respect for whatever equipment I touch, whether it is electrical or mechanical, because it has no respect for the operator.
It was drilled into me in the first week of my apprenticeship during induction and amplified on a visit to the old Safety Council premises up in London where I witnessed various displays of mock ups of real life accidents too gory to describe here caused by the operators of the equipment
It was stressed to us that none of the accidents could be attributed to the equipment itself.
I hope this clarifies my position and I repeat that it was not my intention to personalize or offend anyone who posted in this thread nor steer it off topic.

 

[neptune]

To me, this has been a great thread. I personally don`t mind if a thread wanders on and off topic a bit. At least it gives us a bit more to read. To me, a person`s spelling and punctuation is a lot less important than what he has to say. As I may have said before, the purpose of language is to convey our thoughts. If it achieves that , then other factors are of secondary importance. I heard a story once about a big company that was short of a salesman. The sales manager took on this guy at short notice without having the chance to really find out much about him, except that his name was Charlie.
They gave him a car, and a sales kit, and sent him off to Chicago the same day. Nothing was heard from him for a week. Then the sales manager received a text message which read as follows.
" Hi itz Charli. Bin selin in chicawgo . Sould a Millyun.See yew nects wick."
The manager was deeply shocked on two accounts. Firstly he had employed someone who was hopeless at spelling. Then there was the situation that not even the best salesman had sold more than ten thousand units in a week. So he sent the following memo to the entire sales force .
"it sims two mee az ow uz gies av spend two merch tyme lernin ow two spel, and not enuff tyme lernin ow two sel. Wen charley gitz bak ees gunna shew uz ow tu doo it proppa."

 

[flecc]

I'm betting that story is apocryphal Neptune!

 

[muckymits]

Posted by member Andrew Harvey previously:

"To test the Hall sensors on in the motor is more tricky, you have to apply a voltage to the thin red and black motor cables, a small 3 to 9 Volt battery pack is ideal, positive to the red, negative to the black, then with a multi meter set to low volts DC measure the voltage between the positive supply and the hall sensor return cables, then with your third hand spin the wheel. So if you start with say the green hall sensor cable connected to the meter, you should see a voltage between 1v and the voltage of your battery, turn the wheel, this voltage should change as the wheel moves, going from a low voltage to a high. Repeat this with the other sensor cables.
If your wheel is geared with a freewheel turn it backwards."

Its just as easy to build one of these Endless-sphere.com • View topic - How to Determine the Wiring for a Brushless Motor the box to put it in cost more than the bits. If any one is passing they can have mine, its thrown in the bottom of my box.

 

[flecc]

Indeed, most could even "breadboard" one in a few minutes.