Magic Pie / Smart Pie as Generator

[RooGM]

What I'm going to do with mine is run the Magic Pie output into a solar charge controller and that should give me a smooth 24v output into my 2 12V SLA batteries (wired in series for 24V) and then into my 24V 500W inverter.  I have already tested running appliances just with the Magic Pie and the inverter and as long as I maintain a steady voltage of 26-30v the inverter stays on.  I can comfortably put out a sustained power of about 280 watts.  This is really exciting to me as I like to exercise for an hour per day anyway and being able use that energy to put all those watt hours into a battery bank is really cool.  To put it into perspective, 280 watts is enough to simultaneously charge over 50 iPhones. 

I will be putting the energy into my SLA batteries and using them to charge all my devices (phones, laptop, LED lamps, camera gear, flashlights, two-way radios, portable power banks etc.).  I can even use some of the energy to charge my e-bike battery.  Technically if I pedal-charged my e-bike battery it would be a 100% human powered electric bike.  I also have some solar panels I get power from but there isn't always enough sun. 

[RooGM]

Here's what I have learned today in my experiements:

1. With a 24v battery (or 2 x 12v in series) between the Magic Pie output and the Inverter it is much easier to get a steady voltage around 24-26v when pedalling.  With the battery in place it takes a serious pedalling effort to push the voltage up high enough to trip the voltage overload on the inverter.  So no worries about this.  This is good.

2.  Setting the Magic Pie controller to 24v via the software makes no difference to the output.  No matter whether you set it to 24v, 36v or 48v, the voltage output is the same when pedalling.  This is also good as I don't need to change the voltage setting every time I switch from riding my bike to using it as a generator.

[RooGM]

My Solar charge controller came today and it works great!  It's a very inexpensive model (only $26 CAD) but it does exactly what I need from it.  It detects the battery voltage and adjusts the charge voltage accordingly.  It's amazing actually because when connected to one 12v battery I can pedal quite hard and the voltage remains around 13v.  When I connect two 12v batteries in series for 24v and pedal at the same rate the voltage keeps to around 25v.  I have a voltage monitor on my Bike that's independent of the charge controller and even that stays around 13v or 25v so I believe the charge controller is not stepping down the voltage to maintain a steady output, instead it is drawing more or less current as it needs, in order to keep close to the right charging voltage for the whichever battery configuration is connected.

So I'm running two 12v batteries in parallel, charging via the Magic Pie + charge controller and running a 300W 12V inverter from the batteries.  12v inverters are much easier to find and much cheaper than 24v inverters and with a charge controller in the circuit there is no need for a 24v unit. 

[MrBulp]

hi RooGM,

thank you for sharing your experience with Solar Charge Controller.. will try it if I have enough fund to buy it here..

i wonder if I can connect 2 Magic Pie as generator to have the same output thru only 1 inverter...

the reasons is, to cut cost for inverter.. haha

have anybody try to wiring 2 Magic Pie to 1 inverter? with battery or without it..

[RooGM]

I don't understand what you mean about cutting the cost of the inverter by connecting two Magic Pies.  Can you explain?  You can power one 24v inverter from one Magic Pie.  And if you add a solar charge controller and a 12v battery you can power a 12v inverter which is cheaper than a 24v one.

[Ecobully]

@RooGM,

Nice going with your plans! You should now charge your eBike battery pack(s) with the MP in dynamo mode. Then use that stored energy for assisted bike rides. SLA batteries are not offer too many duty cycles, but if you are just using them in a "buffer" mode between the inverter and dynamo would it last quite a bit longer?

I would like to create a comfortable recumbent setup where people in the media room can watch a movie and pedal at the same time creating enough power to drive all electronics.

[RooGM]

I feel like I hijacked your thread, Mr. Bulp so I have posted details of my generator setup in a new thread here: http://goldenmotor.com/SMF/index.php?topic=5904.0

[MrBulp]

I don't understand what you mean about cutting the cost of the inverter by connecting two Magic Pies.  Can you explain?  You can power one 24v inverter from one Magic Pie.  And if you add a solar charge controller and a 12v battery you can power a 12v inverter which is cheaper than a 24v one.

hi RooGM,

i got the answer from Solar Panel diagram... so I guess I have to buy Solar Charger Controller to "save" some money for inverter...

[RooGM]

You can get a really basic and cheap charge controller, such as this one for $13 CAD: https://www.amazon.ca/Docooler-Controller-Battery-Regulator-Protection/dp/B00L37KZI6/ref=sr_1_3?ie=UTF8&qid=1458834030&sr=8-3&keywords=charge+controller

I'm using this one which I got on sale for $36.  It has a good display that tells me battery voltage, generator/solar panel voltage and the current being put into the battery: https://www.amazon.ca/Patec%C2%AE-Solar-Regulator-Charge-Controller/dp/B00MHNCHCW/ref=sr_1_2?ie=UTF8&qid=1458834030&sr=8-2&keywords=charge+controller

 

[MrBulp]

Hi guys.. I just want to update to this topic...

2 weeks ago id just doing some demo with my Magic Pie V5 as pedal generator that been set to 24V... thats mean anybody have to pedal around 20-30km/h to get 24V regardless any load thats been throw for output.. such as 2 x 60Watt deskfan etc etc..

sad thing to my demo is someone really think that the faster you pedal the more watt you generate.. its true when DC to DC conversion...
but its not the same when you use motor controller & the output is in AC..

my 24V inverter & Magic Pie V5 controller died after I think that guy pedal so fast (around 50-60km/h) in few seconds!! the Magc Pie controller still have battery indicator light on but couldnt get it to work as motor... mosfet burn??

the inverter fuse didnt break at all!!

id open the stator & saw this.. some plate not inline  

[Bikemad]

The damage to the stator most probably occurred during removal, as it is very easy to catch the stator against the magnets if you don't keep the stator properly centred while removing it. 

Carefully push the laminations back down again as much as possible, and then add some thin superglue in the gaps before clamping them together again using a "G" Clamp or mole grips etc.

Alan
 

[MrBulp]

Hi Alan,

thank you for the info.. yup maybe.. id just push it back without put any glue back again as at that time didnt have glue..

i have 1 more question to you.. what you think about this diagram below..

[Bikemad]

The circuit looks fine, but there is not enough information:

What are the yellow wires for (the ones connected to the red wires on the input and output)?
They are not fitted on the same JD1230 30A power supply that I looked at:



The exposed male connector blade should really be fitted to the Blender, LED wires and "Transformer" input, which are not "Live" when disconnected. This would prevent the possibility of shorting out the power supply or motor if the connectors were accidentally pulled apart during use. 

The "24-12V transformer" has to be a DC-DC converter type (like the one shown in the photo) rather than the more commonly found coil transformers which would only work with AC power.

Presumably, the LED is rated for 12V use, or else it would require a suitable current limiting resistor to run from the 12V output.

I'm also not sure that the diode (along with its additional 0.6V drop) is really necessary, unless you intend to have a 12V battery connected in parallel with the 12V output.
11.4V is a lot less than the typical 13.8~14.5V usually available on a car's auxiliary electrical supply while its engine is running, and would not be high enough to charge a 12V battery (if fitted).

Alan
 

[MrBulp]

Alan.. thanks for the reply...

id already try to hook the 24DC to 12DC transformer just like my first photo directly to hub motor with controller been set to 24V & its failed to start been generator..
i use the 12V power inverter

i wonder if there is specific output from Magic Pie controller that prevent this transfromer to be working ? since its work with just directly to 24V DC Power inverter to AC..

regards

MrBulp

[Bikemad]

Have you tried connecting a 24V battery to the controller and then measuring the battery voltage to see if it rises above the open circuit battery voltage if you pedal faster?

I suspect that the controller is only supposed to pass the generated power from the motor to the battery when regenerative braking is used, but the electromagnetic dynamic braking effect at slower motor rpm might prevent you from pedalling fast enough to produce any useable power.

Connecting a three phase rectifier to the three phase wires would produce a more consistent and much better current output for powering a DC-DC converter, but you would need to devise a way of feeding three additional wires (one for each of the phase wires) to the outside of the controller where a suitable connector plug could be fitted to allow the regulator to be plugged in when generated output was required.

If there was room to fit the rectifier inside the hub, you could permanently connect it to the three phase wires and then join the two DC output wires to the Red and Black battery feed wires on the inside of the controller, but I suspect this might make the bike more difficult to pedal at higher speeds without motor assistance, and could also overcharge the bikes battery (or the controller) at very high speeds (long downhill runs where the maximum unloaded motor speed is exceeded)

I suspect your easiest option would be to use an external controller with a connector on the phase wires to allow them to be easily swapped between the controller and the rectifier. 

Alan