Is a shunt working for you

[Sonar.sonar]

I have a Fido M1 Pro. Yep taking my chances I know but anyone shunted on of these and what results did or do you get out of it .

 

[saneagle]

I have a Fido M1 Pro. Yep taking my chances I know but anyone shunted on of these and what results did or do you get out of it .

What is the maximum amps is written on the controller?

 

[Sonar.sonar]

Is that the same as the battery as I have not taken the controller out but the battery is
capacity 12.8 Ah / 614.4 Wh. Voltage 48 volts
will remove the controller if that’s the only option. The motor is 500 watts

 

[Sonar.sonar]

Not much info here. This is a replacement from the Fido website

 

[saneagle]

Is that the same as the battery as I have not taken the controller out but the battery is
capacity 12.8 Ah / 614.4 Wh. Voltage 48 volts
will remove the controller if that’s the only option. The motor is 500 watts

The first thing you need to do is take the controller out and look inside it to see what type of shunt/s it has because you can't solder solid state one's, though you can adjust their value by soldering more solid state ones over the top using the formula 1/R = 1/r1+1/r2+ .....+1/rn.

You need to have some understanding of the implications, of which there are two main ones. Can your battery provide the additional current, and will the controller become too hot?

When you draw current, the battery's voltage drops down in proportion to how much current you take it from it. If you have an LCD that shows real time voltage you can see that directly, otherwise you need to temporarily connect a voltmeter to see what it is. You observe it when drawing max current in max assist level while going slowly up a hill with maximum power. If it anything more than say 3v drop, it's probably not a good idea to increase the current. The higher the current a battery has to give, the shorter its life, and if you go too high (indicated by the voltage drop), you can shorten its life drastically.

According to adverts, your controller limits the current to 18A. That's its maximum current. It's rated current would be half of that, which means it should be able to run all day at 9A without overheating, but if you want to go up very long hills, there's a fair chance it could overheat as it is.

You controller is contained inside the frame, so it difficult to determine how hot it presently gets with your type of riding and rides. It might be an idea to put a temperature monitoring device on it to find out.

Having said all that, from my experience, every controller I've modified has been able to deal with a 25% increase in current, and so has the battery, but that's no guarantee that any other system can cope with it.

When you go fast, the back emf from the motor restricts the current, so increasing the current limit won't make any difference in the upper speed range, only acceleration and hill-climbing would be better.

Final point: Check the three motor phase wires coming out of the controller to see whether they're PVC or PTFE. The PVC ones can melt if you go too high, but not the PTFE ones, so if you do the modification, you should check afterwards how well they coping if PVC, otherwise you risk blowing your controller's MOSFETs when the wires short out.

 

[Sonar.sonar]

Ok thanks a lot to think of
I have already done the increase speed thing and it’s faster I will have another rethink if it’s worth possibly damaging something with a shunt I have a hill in mind to try it on now so see if it goes up it’s not a long hill but a trioblade fat wheeled with a 250 motor won’t go up it but I have in the past
so worth having another try first …

but Thankyou all for your replies . Again Thankyou

 

[saneagle]

Ok thanks a lot to think of
I have already done the increase speed thing and it’s faster I will have another rethink if it’s worth possibly damaging something with a shunt I have a hill in mind to try it on now so see if it goes up it’s not a long hill but a trioblade fat wheeled with a 250 motor won’t go up it but I have in the past
so worth having another try first …

but Thankyou all for your replies . Again Thankyou

18 amps and 48v should be enough to get you up most hills.

 

[Nealh]

As mentioned 18a/48V should be adequate for most riders , 864w of battery power equating to approx. 600 - 620w at the hub .

 

[Sonar.sonar]

Thanks for all the information .

the next thing is trying to work out how to disable the throttle at a moments notice. Just in case

I am near on 70 now and use a disability scooter it’s limited to 6 mph
but my Bike throttle. Is not limited is there a temp fix that can be turned both on and off .

i can restrict and de restrict the speed quite fast if i have to . But not the throttle.

could I use a 10 watt normally open reed switch .
not sure where to fit and activate yet still thinking about it .
but a 4 mm thick and 14 mm long approx could be put anywhere i guess