Problems with Magic Pie: throttling, braking, cruise control.

[Artem]

Good day, everyone.

I wrote a letter to GM, but maybe someone here could help me with this:

Throttle was sometimes hard to begin uphill, with even slightest elevation. It either stops unintentionally, while I begin to accelerate, or doesn’t start at all. Usually it takes several attempts to start throttling. Motor never gets hot, only a little bit warm.

Electric (regenerative?) brakes almost didn’t work at all. It is possible to stop with them only from the lowest speed of 5km/h approximately. If the speed is more than this, brakes just let the motor to freewheel. I don’t know if they are concerving electrical energy.

When I tried to use USB cable to see, if it is because of controller settings, I couldn’t connect to it. Software starts, when I choose “Connect” nothing happens with the program itself, only the motor starts to beep constantly. “Get settings” didn’t load any, changing parameters and saving them seems to have no effect on the motor behaviour. Only “Disconnect” button worked, but somehow it says that “Get settings” is comeplete, and any changes in parameters reset to their initial state. I found here on forums suggestion, that maybe yellow wire is unconnected inside. But when I opened motor, I saw, that some grey wire is connected to both RX and TX. Looks like it is yellow, but lost it's color.

After approximately 360km, “Cruise control” button stopped to work. I opened motor and checked electrical connection to the controller itself, the button itself and wires are functioning properly. But I have absolutely no voltage reading on the button’s wires.

Please, help!

[Bikemad]

Hi andto the forum Artem.

Throttle was sometimes hard to begin uphill, with even slightest elevation. It either stops unintentionally, while I begin to accelerate, or doesn’t start at all. Usually it takes several attempts to start throttling. Motor never gets hot, only a little bit warm.
Sounds like it could be a poor contact on the battery supply lead, check the connections on the battery to make sure they are still securely connected.

Electric (regenerative?) brakes almost didn’t work at all. It is possible to stop with them only from the lowest speed of 5km/h approximately. If the speed is more than this, brakes just let the motor to freewheel. I don’t know if they are concerving electrical energy.
The regenerative braking will not do much at very low speeds (<5kmh), but it's usually quite effective at higher speeds, the amount of braking will depend upon the wheel size, battery voltage (and type) and the software setting.
If I have my regen switched on, I would have to pedal very hard to try and exceed 10km/h.

When I tried to use USB cable to see, if it is because of controller settings, I couldn’t connect to it. Software starts, when I choose “Connect” nothing happens with the program itself, only the motor starts to beep constantly. “Get settings” didn’t load any, changing parameters and saving them seems to have no effect on the motor behaviour. Only “Disconnect” button worked, but somehow it says that “Get settings” is complete, and any changes in parameters reset to their initial state. I found here on forums suggestion, that maybe yellow wire is unconnected inside. But when I opened motor, I saw, that some grey wire is connected to both RX and TX. Looks like it is yellow, but lost it's color.
I've never tried programming, so I cannot really comment on this particular problem, but several members have recently reported this constant beeping and are unable to program the controller.

After approximately 360km, “Cruise control” button stopped to work. I opened motor and checked electrical connection to the controller itself, the button itself and wires are functioning properly. But I have absolutely no voltage reading on the button’s wires.
Did you check the voltage on the cruise connection on the controller when you had the motor apart?

When was your wheel kit purchased?

Is the cutting out problem a recent development, or has it been like this from new?

Carefully check all of the connections, especially the battery (and switch if fitted), and see if you can find anything obviously loose.

Alan
 

[Artem]

Thank you very much!

When was your wheel kit purchased?

Is the cutting out problem a recent development, or has it been like this from new?

Carefully check all of the connections, especially the battery (and switch if fitted), and see if you can find anything obviously loose.

Sounds like it could be a poor contact on the battery supply lead, check the connections on the battery to make sure they are still securely connected

Bought it at 5th of May, arrived at 23d, started exploitation at the beginning of June. It was from the very beginning (my first disappointment in MP ).

But yesterday it was more then usual, and I have checked connection as you say. Indeed, the power plug in the battery itself was somewhat loosened. Fixed it, will check tomorrow, if it helps.

Do you mean that I need to open battery case to check key-switch and so on? (it is sealed everywhere with "Tear invalid" )

The regenerative braking will not do much at very low speeds (<5kmh), but it's usually quite effective at higher speeds, the amount of braking will depend upon the wheel size, battery voltage (and type) and the software setting.
If I have my regen switched on, I would have to pedal very hard to try and exceed 10km/h.

Yes, I thought so, and that is my point - I can stop electrically only if I'm very slow. If my speed is more than 7km/h - brakes do nothing except for stopping power to the motor. I have 26" wheels, standard GM battery 48V 12Ah. Software says 50% regen braking, but I don't know should I believe it, considering my connection problems.

I've never tried programming, so I cannot really comment on this particular problem, but several members have recently reported this constant beeping and are unable to program the controller.

Well, I hope GM will answer something about that.

Did you check the voltage on the cruise connection on the controller when you had the motor apart?

Yes, I did, absolutely zero volts.

[SydneyCommuter]

Hey

First you have to distinguish between things that are working to the normal characteristics and the faults.
The delay is due to the regen and the controller and is normal characteristics according to Monkey who I'd credit with knowing his stuff.

The cutting out however is an issue and needs to be solved, I have this also, I suspect the current/battery management, but the usb cable is a blocker on trying some settings to isolate.
Hopefuly the USB controller issue with come to light soon as its a pain to many.  I'll have a crack at it myself when I rebuild my wheel who knows??

Personaly the regen braking is something I'm thinking of turning off or down.

watch out for the anderson plug that is a certain early fail point, mine lasted 5 mins litteraly.

good luck with the other issues sounds frustrating.

Cheers

[GM Canada]

Hi Artem,

If there was a loose conection on the battery take a close look at the plug on the cable and in the battery. I have seen the plug fail and one contact moves back when you plug it in. this still crates a conection but not a very good one. The contacts should tell the story with marks from sparking. The image below shows the contact points in a battery. I suspect the battery cable plug is broken in this case and making bad contact. The image of the battery cable that was sent to me is unclear.

That being said the contacts could also look like this from plugging the battery in when it is switched on. Most people have the battery off when making a connection, but not all.

Gary

[Artem]

Well, I tried, and nothing changed.

I took a closer look at the battery socket, and indeed, one connector was moved back. I disassembled battery. Inside everything looks good, solder is fine, no traces of sparks or burn-outs or something. One wire at charger side had hole in its insulation, I covered it with tape de bene esse. I fixed connector  and assembled battery back.

Well, no changes. I can say that max speed lowered as well, to say by 3-4km/h. If before I could make 42-43 km/h on flat, now it is ~39. I figured out the system - I can throttle well only if I get 21km/h already - then no problem, motor is able to speed up and to maintain speed.

My overall feeling is that it is getting worse every time.

And it is rather uncomfortable to ride without Cruise Control button.

Any suggestions, gentlemen?
  

No answer from GM. I wrote at zhourenli@goldenmotor.com and sales - are those right e-mails?

[MonkeyMagic]

I wrote at zhourenli@goldenmotor.com and sales - are those right e-mails?

You could also give tom@goldenmotor.com a try. It's Toms newer email to  'zhourenli@goldenmotor.com'

Cheers

[GM Canada]

Hi Artem,

Im going to take a guess here as I have recently had ths happen.

My guess is you have a GM aluminum cased battery with keyswitch?

I have a customers battery that worked fine for a few weeks and suddenly started doing exactly as you described. The strangest thing was it read 54 volts right at the battery plug, but when you plug it into the bike no go. I for sure assumed it was the bike untill I tried another battery on it and the bike went fine.Then if you plugged the charger into the battery it would light up the throttle lights for about 3 seconds then go out. Then about 3 seconds later the lights would come on again.Then off, then on for as long as I leave the charger. Now it thought for sure it must be the BMS. But I have never had one fail. This is weird.

After reading posts about key switches not working properly and having to be cleaned. Then thinking I have sent out a few replacement keyswitches myself to replace ones that were inconsistant at turning on. I decided to try bypassing the switch to see what would happen. I opened the battery cut the wires at the key switch and bypassed it. Be carefull if you try this as the red wires are live and will ground out on the case.

Now the battery and bike work perfect! I had someone contact me and after some converstion we thought his controller had failed. After fixing this battery I contacted him and asked him to bypass the battery key switch and now his bike is fine.

My usual method to fix something is to kick it or shake it. If that dosnt work I just throw it away. But I am getting better So if I can fix this I am sure you can.

As others have posted they only cleaned there switch when it started malfunctioning so you may not have to cut the wires. But I used the "lets make sure its the switch" method.

So I have my fingers crossed you have a gm keyswitch and my toes crossed this fixes it

Gary

[Artem]

Well, you guess right, it is exactly this nice aluminium casing (it was one of the reasons I choose GM).

I have disassembled the battery as you can see, and found absolutely no flaws whatsoever, and in the key switch as well. And I don't have this behavior with throttle lights. But anyway I'll try your method, except that it is a pity to get rid off the key switch.

And also it doesn't explain, I think, Cruise Control and problems with programming.

It would be nice to have at least whole power and speed back, thank you!

[Artem]

Alas, no luck with it. Made a very nice strand bypassing key switch, but nothing changed.

[GM Canada]

Darn, I thought that could have been it. Oh well. I have to admit though I did also try using a jumped wire to get it to work without any luck. It wasnt until a few days later I did the chop and twist it worked. But I am sure you did a sufficient test. I do feel that if there is a possible loose conection in the ignition or jump wire its enough power loss to kickout the BMS. But of couse everytime I think I know something I'm wrong...

Gary

[Artem]

Well, I have an update here. I bought some kind of cheap wattmeter from DX. It shows the following: seems that there is no amperage cut-off: if I start acceleration, it can be on any number from 3 to 17 amps, engine just stops and no ampers being drawn. (And throttle lights don't go off, as I said before). If I manage to get speed slowly, it draws 18.1 max amp (seems to be a pre-defined limit) and makes approx 900W.

Several kilometers after I noticed, that full battery (~54V) can fall as low as 42.3V at max amperage. And green light go dim - never happened this fast before. I guessed it is because of a poor connection of wattmeter between battery and motor - I couldn't find that SAE connector. It seems to be quite true. This ride was very strange indeed - battery died after, I bet, no more than 25km, while 48km is my usual result.

Well, does it make situation little bit more clear?

PS It started raining, and my poor wattmeter seems to have died, but anyway, he completed his mission

[Thaialien]

Hi all
maybe your controller has gone into sensorless mode or unkown fault that will only give you 50% power/half speed
 { your comments seem to say that }
 (re-check all connections control side  to reset switch off / on ALL  power to reboot controller  )

when connections seem all right ! they may not be !

John L

[Artem]

Well, if it has gone sensorless, shouldn't it beep? No faults in connection as I can see.

Anyway, are the described wattmeter readings normal? For example, I can conclude that inner resistance of my battery is approx (54-42.3)V/18A = 0.65Ohm - is it OK?

[Bikemad]

Sensorless mode does not noticeably reduce the power, it usually stops the motor from starting on its own, but once the motor is turning, the throttle works normally, although I did notice a slight delay on the throttle when running in sensorless mode.

Not all of the controllers actually beep, but you can easily check to see if your does by holding the brake on and then operating the throttle four or five times, and if you're lucky, you should hear a beep.

John, I think you're getting confused with the fail-safe system which allows the cruise button to give half throttle while pressed if either the brake switch or the throttle control fails.

Artem, if your battery is only partially discharged and is being pulled down to around 42V under 18 Amps load, I would say you may have a problem with some of the cells.
Unfortunately, without being able to check each of the 13 groups of cells under load, it will be difficult to locate the faulty ones.

Did your wattmeter return to life again after it dried out?

Alan