Author Topic: Magic Pie loses all power under load at low speed  (Read 41194 times)

Offline Leslie

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Re: Magic Pie loses all power under load at low speed
« Reply #15 on: September 14, 2010, 08:23:27 AM »


I made this for my brushed bike last night.


It uses .037ma and uses 1.48W when the controller is switched on and no power at all when the controller is switched off via the relay..  You must  switch it off to charge the batteries so the little red charge light on my charger tell me if Ive switched the pack off becuae I run no battery gauge LEDs.  Most gauge LEDs are useless for LI usages anyway, and I know how far my packs will get me anyway and buy the right opack for the job at hand.

I have another power control box in the works and the relay part is suggested by Monkey.  It uses a latching mechanism so it uses no power to stay on or off but only requires a small pulse to switch them.

http://cgi.ebay.com/2-PCS-12V-coil-polarized-latching-relays-60A-250V-AC-/250672035433?pt=LH_DefaultDomain_0&hash=item3a5d37b669


The only problem is they aren't DPDT so I am looking at a way of making it not have the controller connected when the charger is engaged..

Bring it on

Offline MonkeyMagic

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Re: Magic Pie loses all power under load at low speed
« Reply #16 on: September 14, 2010, 08:35:56 AM »
You and me both mate .... ;)

Offline Leslie

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Re: Magic Pie loses all power under load at low speed
« Reply #17 on: September 14, 2010, 09:50:07 AM »
Just need another 10 amp DPDT relay to trigger off the mains latching relay on the controller side so the charge point is off when the controller is on and the charge point is off on when the controller is off... Be nice if we could get those 36v coils to run better charge point off efficiency..

Better if out relays were actually DPDT.  This would seal the deal.

Using a dual flip flop latching polarized relay thing may get confused and would be a bugger to set right again.  Doh they are polarized.  It works.
« Last Edit: September 14, 2010, 09:58:57 AM by 317537 »

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Offline Cornelius

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Re: Magic Pie loses all power under load at low speed
« Reply #18 on: September 14, 2010, 02:00:41 PM »
Quote
If the controller remains connected to the pack at all times, the controller draws .08 amps/hour.  80ma.

Now, let's use some real measured numbers here...
I've just measured the current draw on the minus lead, and it is as follows:

Main power on, key on: 52mA
Main power on, key off, alarm on: 19mA
Main power on, key off, alarm off: 2,6mA

Main power on = both main + and - connected from the bat. to the controller
Key on/off = thinner red on/off wire on the controller (at least on the external.)
Alarm on = cruise control pressed within 10sec after key off. (during the 10sec period, the current draw are 19mA.

This is with my 36V, 750W rear hub, 36V, 16Ah gm battery and the 36V external controller (bought last spring.)
« Last Edit: September 14, 2010, 02:02:32 PM by Cornelius »

Offline Leslie

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Re: Magic Pie loses all power under load at low speed
« Reply #19 on: September 14, 2010, 02:41:46 PM »
Does main power on/off mean unplug/plug pack with zap?  I have no idea about how the GM batts are wired.

Yes I was just going on the single figure of what Alan gave me a few months ago.  Maybe controllers differ.  The figure was real with Alans configuration but from my understanding he uses a different pack too, not the same as your figure.

Monkey Magic made a post about the voltage settings (24v 36v 48v) and how they change the way the bike behaves.  I wonder if this would change the power usage too?

It its good to get some real figures.  Alan tested his and got 80ma DMM vary as well.  And the BMS uses some power too I believe but not too much but that would be hard to test.

It would almost take a year to flaten a 16ah @ 2.6ma battery but a month for a 19ma.

My system uses 0ma main power off, 70ma power on.  Its linear regulators and I wont be using a GM pack.

But I think it stands that if you leave your bike switched on and maybe for get to charge there is a higher chance to pack failure. I wonder why Alans tested at 80ma and yours test 52ma even though 80ma is still smallish you can see that 60% makes a difference over a month..  I think some may be unaware of how it can add up if you were to foget to switch you pack off after a ride so it remains that one should unplug a battery too or use proper switch.

I think I will be using the latching relays for my lithium packs as they use nothing but a short pulse to achieve the switch I can use a key too to enable the latch relay and that uses nothing as well.

19ma is pretty ok for the alarm IMO but still maybesomething you wouldnt want leaching on your capacity on a low battery.



 
« Last Edit: September 14, 2010, 02:47:43 PM by 317537 »

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Offline Cornelius

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Re: Magic Pie loses all power under load at low speed
« Reply #20 on: September 14, 2010, 03:18:46 PM »
Yes, 'Main power on/off' would be plug/unplug the main plug from the pack. (I described how the gm pack are wired, and my modifications in an earlier post in this thread...) :)

I haven't disconnect my battery completely at all this summer; just turned it off with the key, even when I charge it - which I do frequently. (Some exceptions when I had some problems with water on my bms...at that time, I also measured the cell voltages; all was within 0.01V of each other.)

My home place are a pretty safe area, so I doesn't activate the alarm here; only when I park in public places...
« Last Edit: September 22, 2010, 10:48:16 AM by Bikemad »

Trond

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Re: Magic Pie loses all power under load at low speed
« Reply #21 on: September 29, 2010, 02:21:39 PM »
Hello. same problem still. Have measured the voltage drop and it is very low when this happens. from 55 to 54volt. Have checked the contacts and everything looks good. Voltage drop is measured into the pie and the battery. Considering buying new electronics inside the pie. Can it be purchased? Price?

Offline Bikemad

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Re: Magic Pie loses all power under load at low speed
« Reply #22 on: September 29, 2010, 02:43:42 PM »
Trond,

It certainly does sound like a controller fault to me, and as it's less than 12 months old, it should still be covered by warranty.
Try sending another email to tom@goldenmotor.com explaining the problem as simply and clearly as possible and see what he says, and let us know the outcome.



Alan
 
« Last Edit: June 30, 2017, 08:32:04 PM by Bikemad »

Trond

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Re: Magic Pie loses all power under load at low speed
« Reply #23 on: October 12, 2010, 01:45:40 PM »
No Answers from GM >:(

Trond

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Re: Magic Pie loses all power under load at low speed
« Reply #24 on: January 08, 2011, 08:40:24 AM »
Still no answer from GM. Considering buying a new controller. Which type shold I buy? External or internal? GM or other brand. Does GM sell only controllers? What price? Suggestions?

Offline Andrew

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Re: Magic Pie loses all power under load at low speed
« Reply #25 on: January 08, 2011, 10:36:46 AM »
GM China sell internal and external 'magic controllers' for about $33.00 USD I think, but then of course there is shipping.    Where are you in the World? you maybe better off finding out if there is a dealer in your country, and then at lesat you will get better comms and guarantee.

Some people as far as I know go for Infineon controllers, but only if swapping from a GM external magic controller. But i'm a complete novice, so I do not know specifics.

If you already have an Internal magic controller then changing for an external will probably be very difficult unless you are  electronically skilled

Andrew
« Last Edit: January 08, 2011, 10:39:44 AM by Andrew »

Trond

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Re: Magic Pie loses all power under load at low speed
« Reply #26 on: January 08, 2011, 12:53:04 PM »
I am from Norway. If I get some instructions I can change from internal to external. The price from GM is ok, if it will work well. In Norway it does not get very hot. Seldom abow 25 celcius. Perhaps I try new GM internal first. If so do I need program cable? Any toughts about all this?

Trond

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Re: Magic Pie loses all power under load at low speed
« Reply #27 on: January 08, 2011, 12:55:39 PM »
The new dealer in norway did not respond to my mail.

Offline Bikemad

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Re: Magic Pie loses all power under load at low speed
« Reply #28 on: January 08, 2011, 01:09:35 PM »
The new dealer in norway did not respond to my mail.

Perhaps you should try the phone instead:
Golden Motor Norge
Folkvordveien 84
4318 Sandnes
NORWAY
Tel: +47 40408650
Email:lars.ove.lofthus@lyse.net

Claudio Forlini
BRATTLIEN 38
5019 BERGEN
NORWAY
Tel: +47 94482234

Alan
 

Offline Trond Jacobsen

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Re: Magic Pie loses all power under load at low speed
« Reply #29 on: January 15, 2011, 03:13:44 PM »
Can not find internal controller for sale on GM Website. Only program cable. My old internalcontroller gives good torq and speed(40-45km hour) Does the new internalcontroller give the same performance? The only problem with the old one is cutting of at low speed.