Throttle indicator problem - simple solution? and other questions...

[Supatrike]

Hey all,

I am finally getting around to installing my new GM Magic Pie and I have a few problems...

Here's what I bought:  26" Front Wheel MagicPie(Internal Controller) No USB Cable ThumbThrottle No Pedelec 36V12AH + Charger

Problem 1) On full charge, the battery only reads 29V? 
Problem 2) The battery indicator always reads "empty" - from searching the forum it seems that I might have a 48v indicator being used with a 36V battery...  what can be done?  If this is the case then, should I be sent the right part?

Other questions:
1) I have the internal controller, is there a horn or alarm system - if so they aren't working.
2) GM China sent me a bad brake actuator, I've asked for a replacement - will I ever see it?  any advice for getting help from them?

Any help is much appreciated! Images posted below.

Bart

[Bikemad]

Problem 1) On full charge, the battery only reads 29V? 
Problem 2) The battery indicator always reads "empty" - from searching the forum it seems that I might have a 48v indicator being used with a 36V battery...  what can be done?  If this is the case then, should I be sent the right part?

Other questions:
1) I have the internal controller, is there a horn or alarm system - if so they aren't working.
2) GM China sent me a bad brake actuator, I've asked for a replacement - will I ever see it?  any advice for getting help from them?

Bart, 29V is pretty low for a 36V battery, so your gauge is probably working correctly, unlike your charger which must be set to the correct mains voltage to work correctly.
On the back of the charger, you should have a switch to select 230 for Europe and 115 for USA, set this to the correct position and try charging the battery again and let us know the result. It should read around 42V fully charged.

There is no horn or alarm system on the internal controllers, just a tiny buzzer, used for feedback and to indicate some possible failures.

Regarding the brake actuator, if you send them a picture and a brief description of the fault to tom@goldenmotor.com, using easy to understand terms, you should get a response, and hopefully a replacement item too.

Please let us know the outcome regarding the replacement for the faulty part.

Alan
 

[Cornelius]

I can give you an answer to problem #1 and 2...

A fully charged 36V battery should measure around 41-42V. Could it be that you have received a 24V battery?! (there should be a sticker somewhere on the battery...)

If the output of the battery are truly 29V, then the battery indicator are correct; 29V are very empty for a 36V battery. (A 36V battery are considered empty at around 32V, and the Low Voltage Cutout would kick in around there...)

Edit:
Ah, Alan managed to give some more info while I was typing...

[Supatrike]

Thank you, I am grateful!

There is not any 110/220 switch on my charger... I'll contact GM about this and let you know the results.

I hope I can get this straightened out, as I'd like to build more of these and so far like the GM product (but so far I've only used it for about 5 miles).

Bart

[Bikemad]

There is not any 110/220 switch on my charger... I'll contact GM about this and let you know the results.

Hi Alan
Thank you for your advice.  Several posts (including yours) mentioned a voltage input switch. Initially I didn't see it but on a second look I did find a small toggle at the back of the charger which has 230 and 115.  It was set at 230.  I reset it to 115 volt and now it is charging and I am optimistic that things will work out.

Bart, it might be a good idea to have a closer look at your charger, as it might not be as obvious as you might think.

Any chance someone can post a picture of this switch to show exactly what it looks like?

Alan
 

[GM Canada]

Not the clearest pictires, but they should do. It is a simple sliding switch the seems to be easiest to flick with a ball point pen. When you flick it back and forth it should move quite freely and you can tell it is working by how it feels. I have had one charger the the switch made no difference. It didnt feel right when you flicked it and it always stayed in 230 mode. At least I assume it was stuck on 230 mode and  that is why the charger didn't work.

Also the 2 amp chargers GM has are auto voltage switching and no switch exists for switching voltage.

They come in 24v2a, 36v2a and old style 48v2a and look like this



The new style 48v3a with the voltage switch looks like this.



Gary

[GM Canada]

Man I have to say that is one Awesome looking trike

I have a simple solution to detemine if the battery is 36 or 24 volt. Weight it. I know when I handle them I can tell what they are by how heavy they feel.

Tells me what the weight is and I'll tell you what it is.

Gary

[Supatrike]

thanks Gary and Alan!!!

I have the 2 amp auto switching kind without the switch Alan mentions... damn!  I'll weigh it tonight.

Thanks for the compliment on the trike.  There's still a ways to go, and I'll post pics to the forum when it's done.

I took it on a maiden voyage last night for about 5 miles.  I thought it ran pretty good - I didn't know what to expect. 

Will my use hurt the battery or motor if it's not fully charged? or if it's only a 24V battery?  Though, I'm now guessing it's 24V. 


Bart

[DirtyGinge]

Hi Mr supatrike

Tell us how you built the frame please please please ( just a quick techie guide), im really thinking about a custom quad / trike frame ,, welded steel ?

I love it

[GM Canada]

thanks Gary and Alan!!!

I have the 2 amp auto switching kind without the switch Alan mentions... damn!  I'll weigh it tonight.

Thanks for the compliment on the trike.  There's still a ways to go, and I'll post pics to the forum when it's done.

I took it on a maiden voyage last night for about 5 miles.  I thought it ran pretty good - I didn't know what to expect. 

Will my use hurt the battery or motor if it's not fully charged? or if it's only a 24V battery?  Though, I'm now guessing it's 24V. 


Bart

No you wont hurt anything, The pie can run from 24-48 volts and the battery has its own BMS with kickout protection if it get to low. If the battery is at 29 volts then definatly the internal controller inside the motor is set at default of 24 volts. Otherwise it would not run.

Can we see any pictures of the charger details. Like what exactly does it say on the charger.

Gary

[Bikemad]

Any chance someone can post a picture of this switch to show exactly what it looks like?

Thanks for the prompt response Gary, those pictures show the switch fine, it's a shame that Bart's problem isn't the switch though.

Bart, I'm now pretty sure it's a 24V battery you have, which should charge to around 29.4V but I don't know how much harm a 36V charger might be doing to it. Could it also be a 24V charger that was actually supplied, it may be marked 29.4V?

I don't know how well the the Battery Management System (BMS) inside the battery will handle it, but I would be reluctant to continue using a 36V charger on it, just in case something is being overloaded and likely to fail.

Did you measure the battery voltage after your 5 mile run?

What voltages are marked on the charger and the battery casings (or the box it came in)?

Alan
 

[Supatrike]

Thanks for all your help - hopefully we'll get to the bottom of it.

The battery is about 11.5 pounds. There is a new photo posted here that shows the marking where it says 36v12ah.
There is a pic of the charger label too.

I didn't check the charge after the 5 miles.

For DirtyGinge I posted an old pic of the original trike from when I bought it.  I got it from Craigslist and it was in sad shape.  It had a broken headstock, broken seatpost hole, the front shocks were bending under the weight (leverage) of the tire, and the seat was unattached.  Oh, and the rear axle was welded to the frame, which I've since found out is not a bad idea since the bike twists through turns and the chain can come off.  I'll send many more pics later, but to give you an idea of scale - these are 26" rims and the full length of the bike is 9 feet. 






Bart

[Bikemad]

The battery is about 11.5 pounds. There is a new photo posted here that shows the marking where it says 36v12ah.

The label may well say 36V 12AH, but I think it's a 24V16Ah pack that's been wrongly labelled, as a 36V pack would not work at 29.1V because the LVC of the BMS would have cut off the supply well before the output fell that low.

It's difficult to tell by weight without using pretty accurate scales for both readings (a confirmed 36V pack and yours) as there should only be around 0.44lbs (2 cells @ 92g each plus some extra wires) difference in the weight of the two batteries (36V has 30 cells, 24V has 28 cells), if two different scales were out by just 2% each in the opposite direction, you could not be sure of the result, but it would be OK if you compared two batteries using the same set of scales.

I would want to remove the end cover and see how many balance wires are going to the BMS board, but you will need to get permission from Tom before you dismantle anything.

Here's a 48V 13cell BMS board with 12 balance leads:



The 36 volt battery has 10 balance leads, and I would expect the 24V to have only 7, but it might have 8.

It will be interesting to see what your battery actually has on the inside, compared to the 36V 12AH sticker on the outside.

I expect we will find out eventually.

Alan
 

[GM Canada]

Alan is correct about wieghing it not really being a reliable way of telling the battery type. When I wrote that I missed the fact it was 36v12ah I was thinking 36v16ah and 24v16ah being very different weights.

Gary

[Bikemad]

im really thinking about a custom quad / trike frame ,, welded steel ?

Have you made a start yet? 

Alan