Author Topic: Mini motor with programmable controller and 48v?  (Read 5764 times)

Offline Hardcore

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Mini motor with programmable controller and 48v?
« on: March 29, 2011, 01:12:31 PM »
Is it possible to use 1 mini motor, front or rear, with a programmable controller set to the lowest standards for continious amp, peak ampm voltage and regen?
I've got a 48v gm battery but it drops voltages to fast but on the lowest setting it might still get enough miles for my friend.
Now I can get 12km on full throttle but if a minimotor isn't pulling to much amp so the voltage doesn't drop to much, will the mini motor take him much further

Offline Bikemad

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Re: Mini motor with programmable controller and 48v?
« Reply #1 on: March 30, 2011, 12:28:39 AM »

Kevin, the minimotors don't have regenerative braking, and as you would be using a 48V pack, the voltage would not be adjustable. ;)

Obviously the battery will run for longer if the current is reduced, but the speed and acceleration will also be lower too. If your Battery Management System is cutting out early because of a faulty group of cells reaching their minimum voltage, it should run for a lot longer under a reduced output load.
It's difficult to try and estimate how much greater the range would be on a minimotor, but I would expect it to be almost double if the maximum current was reduced by half.

Unfortunately, the only way to find out for sure would be to actually try it and see what results are obtained.
As you don't have many hills where you live, the minimotor will not really have to struggle much, so a lower current might still provide an acceptable level of assistance.

Alan
 

Offline Hardcore

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Re: Mini motor with programmable controller and 48v?
« Reply #2 on: March 30, 2011, 01:00:03 PM »
yes indeed, 25km/h is fast enough so converting a 48v pack to 24v 24ah pack would also be possible right?

Offline Bikemad

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Re: Mini motor with programmable controller and 48v?
« Reply #3 on: March 30, 2011, 02:36:40 PM »
converting a 48v pack to 24v 24ah pack would also be possible right?

Unfortunately, it's not quite that simple. The 48V pack consists of 39 Cells connected into 13 (13 x 3.8V = 49.4V) series groups of 3 cells in parallel (3 x 4Ah = 12Ah).

If you had three more cells (which there should be room for inside the battery casing) it could be rewired to give 7 series groups of 6 in parallel (26.6V 24Ah) but you would need to replace the BMS board and your charger!

It would also be possible to use 36 of your 39 existing cells to give 6 series groups of 6 in parallel (22.8V 24Ah), but I think the LVC on the controller might operate too soon. Again, you would need to replace the BMS board and charger.

I really think it will be a lot less hassle to keep it as a 48V pack and just program the controller to a low current setting on 48V, and perhaps program in a legal maximum speed if required.

Alan
 

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Re: Mini motor with programmable controller and 48v?
« Reply #4 on: March 30, 2011, 09:39:33 PM »
I don't need fast acceleration, I just want to give my friend a present suprice.
I've got brake lever, cruise control, throttle, the whole package already here.
So ordering a mini motor with cruise controller would be the only thing I needed to succeed.
Thanks for answering my questions,

but how do you program a controller to only go 25km/h or lower with max output power of 400 and 250 watt continious?

Offline Bikemad

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Re: Mini motor with programmable controller and 48v?
« Reply #5 on: March 30, 2011, 11:51:24 PM »
But how do you program a controller to only go 25km/h or lower with max output power of 400 and 250 watt continious?

You would also need the PI-200E interface cable:



And then adjust the FWD scale speed to give the required top speed:



The necessary software can be downloaded here.

Alan
 

Offline Hardcore

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Re: Mini motor with programmable controller and 48v?
« Reply #6 on: March 31, 2011, 06:15:21 AM »
Thanks