Overheat protection during up and downhill

[Velonaut]

My wife and I ride a sportive tandem (Koga Miyata TwinTraveller), we converted the bike to an electrically supported bike with a 250 Watt front wheel mini motor from a competitor. Here in the Netherlands on the flat roads the system performed very satisfactory; the mini motor was strong enough to support us up to speeds of 30 km/hour, even with head winds.  However in the mountains of the south of France (Pyrenees) we quickly burned out the motor and we discovered that there was no overheat protection in the motor. We got a new motor under warranty but we will “cook” it again next holidays. We therefore intend to replace the motor for a 36 volt 500 watt hub motor from GM with regeneration ( HBS36F).
The two batteries we have are 36V LIFEPO for 25 amps peak and 10 amps continues. One is connected at the time.

Can anybody tell us:
- if the 500 watt motor has overheat protection?
- if the controller has an overheat protection?
- if we can use  the system unlimited during climb?
- if we can use the regeneration system unlimited during decent?

[Leslie]

I don't understand how someone could receive warranty when they know full well they burnt their motor out from excessive use..

The internal controller Magic Pies are heat protected, but hey do you want a motor always shutting down on the hill on you.

If you want thermal protection and reliability and want to believe in Santa or anything you read in a forum post by GM, for your usage Id get 40 ah pack and dual Magic Pies.

[GM Canada]

at the time.

Can anybody tell us:
- if the 500 watt motor has overheat protection?
- if the controller has an overheat protection?
- if we can use  the system unlimited during climb?
- if we can use the regeneration system unlimited during decent?

no heat protection on the motor
      - unless they changed something recently

no heat protection on the external controller
      - unless they changed something recently

unlimited use during a hill climb with two people you better pedel allot to help the motor - 500 watts is not a real hill climber

Some think they have blown theitr controller with regen, I tend to dissagree. I use a cycle analyst and you can see the watts going back in during regen and its never really that high.

I would suggest for you a Magic Pie as it is a better hill climber. Two pies are even better.

Gary

[GM Canada]

I don't understand how someone could receive warranty when they know full well they burnt their motor out from excessive use..

Id have to say I aggree with you on that! I'm not saying this is what this person did. I am more reffering to a recent trend. I now have people ordering exteral Magic Pies with no controller. The obvious answer is there going to overpower it with another high powered controller at some whacked out voltage. To these people I say up front "Don't expect a warranty if you burn out your motor"

Gary

[Sundsvall]

A Magic Pie and a Infineon controller with a calibrated CA-DP. Then you can set the controller to max speed, max amps or a number of more settings directly from the handlebar and still have a real hill climber.

Peter

[Velonaut]

I like to reply to some of the suggestions made in the answers;
- the motor is for support, not the only source of power. We peddle ourselves with full power, which is thus also the intention. Due to my wife's back injury she needs some "electro-mechanical" support to still make rides we like .
- the 250 watt support delivered by the initial motor proves to be sufficient.
- the initial motor was promised (on paper) to be resistand to heavy use in the mountains, but we found that it was not, and we got therefore warrenty.

The new motor must be resistant to overheat or have a temperature indication or a protection. Better to switch off than burn out.

[Velonaut]

Gary, can the cycle analist give some form of protection?

About the Magic Pie; we are familiar with the Magic Pie. We have one on our Go-One Velomobile, we find the motor power at low speeds a bit disappointing (amp setting: 7continues/25max). We also think that a Magic Pie is too heavy for the tandem and has low mecanical output at low speeds. The mini motor gave reasonal mechanical power and is very economical with electricity.
Note: during a climb in the mountains with our tandem we cycle at a speed of 6 to 12 km/hour (full human power and full motor power). This may take up to 1 hour.

[Sundsvall]

Gary, can the cycle analist give some form of protection?

About the Magic Pie; we are familiar with the Magic Pie. We have one on our Go-One Velomobile, we find the motor power at low speeds a bit disappointing (amp setting: 7continues/25max). We also think that a Magic Pie is too heavy for the tandem and has low mecanical output at low speeds. The mini motor gave reasonal mechanical power and is very economical with electricity.
Note: during a climb in the mountains with our tandem we cycle at a speed of 6 to 12 km/hour (full human power and full motor power). This may take up to 1 hour.

I have a summer bike with a Magic Pie and a winter bike with a 24v 250w mini-motor. They both have a Cycle Analyst, a CA-DP on the summer bike and a CA-SA on the winter bike. The difference between them is that the CA-DP is pre-calibrated for a specific controller and has the possibilities to set Speed Limit, Volts Limit and Max Amps which would be suitable for your needs. It also is a much simpler installation as it’s terminated with a 6-pin plug that connects directly to the controller.

Unfortunately the CA-DP has a huge disadvantage too, as you have to buy a new controller which you don’t have to with the CA-SA.

Depending on which Magic controller, my mini-motor can take nearly 600w in hill climbing. That’s probably too much over time but can only be decreased with a CA-DP or releasing the throttle when it’s too much.

[GM Brazil]

There must some set up at the magic controller with the USB that can deal with this problem...?

[Velonaut]

Setting the magic controller with the USB; we recently installed a Magic Pie in my wifes Velomobile and use 36V existing 10Ah batteries. It is for support so we installed a pedelec for control (also a throttle as back up). We set the amps at 7 amp for a good balance betrween human power and MP support power. We find the climbing power (power at low speeds) disappointing. Also, the support of the MP is difficult to control (compared to the minimotor system (from other manufacturer)). It seems The MP gives all or nothing, and the support stops at speeds of approx 32km (depending on the load/voltage of the battery).

Another option is installing a thermo meter in the mini motor to read the temperature and stop before point of damage (max 120 degrees C). But did not find one yet.

[GM Canada]

Gary, can the cycle analist give some form of protection?

About the Magic Pie; we are familiar with the Magic Pie. We have one on our Go-One Velomobile, we find the motor power at low speeds a bit disappointing (amp setting: 7continues/25max). We also think that a Magic Pie is too heavy for the tandem and has low mecanical output at low speeds. The mini motor gave reasonal mechanical power and is very economical with electricity.
Note: during a climb in the mountains with our tandem we cycle at a speed of 6 to 12 km/hour (full human power and full motor power). This may take up to 1 hour.

I use the CA to control low voltage to protect the batteries. I also use it for setting max speed, max amps, etc. these settings are also available wih the USB to the hub but the CA is more accurate for settings like max speed.

You say the 250w seems sufficient (until it dies) for hill climbing. I would think it is working very hard for that hour so it is at risk of failling. If you are trying avoid a larger motor like the Magic pie then maybe you should consider a dual 250w motor setup, with one in the front and one in the back. You will also find an increase in distance with two motors rather then one. This I found very surprising when I added the second motor on my bike. I find at least a 10 to 15 percent increase in voltage remaining after my daily ride to work.

[Velonaut]

Thanks Gary.  I like the idea of two motors. Do you control them with one controller?

[GM Canada]

Basically you use one controller for each wheel.

Then you split the wires from your

- cruise button to both controllers
- Brake levers to both controllers
- from the throttle the all three wires go to one controller
    and only the red and white to the other

And thats about it. The Diagram bellow was drawn by our friend Leslie and shows how to wire to pies but the concept is the same.

Gary

[Velonaut]

Since the controller can take a 500 watt motor (and more), I suppose one controller can take also 2 x 250W motors, wich makes the diagram even more simple. Just split the output cables. Can you agree?

[Sundsvall]

Since the controller can take a 500 watt motor (and more), I suppose one controller can take also 2 x 250W motors, wich makes the diagram even more simple. Just split the output cables. Can you agree?

Since the motor is brushless the controller doesn’t know where the rotor is. It needs the signal from the hall sensors in the motor to now which phase it should deliver current to. It is impossible to always synchronize two motors to be in the same position.

Peter