Subject: Magic Pie 4 36V to 48V how to modify throttle LED charge measurement

[Meridaman]

Hello.
I just upgraded the battery from 36V to 48V on my Magic Pie 4 e-bike. It seems the motor works properly after setting the new voltage (more power, more top speed etc ), but the led charge lights on the throttle control are always on, even if the 48V battery is discharged ( it's normal I think as the internal circuit is calibrated on the lower 36V battery voltage range ).
Is it possibile to modify the circuit to re-calibrate it on 48V battery voltage range or I need a new throttle controller ?
May changing some resistances ?

Thanks

regards

Sam

[Bikemad]

Hi Sam andto the forum.

You should hopefully be able to fit a suitable resistor into the LED battery gauge supply wire to effectively drop the voltage to the required level, but the resistor would need to be fitted between the throttle switch supply and the battery gauge supply wire (inside the throttle unit) to ensure that the lighting switch is still being fed directly and not through the resistor if the throttle switch is being used to supply LED lights.

Check out this post for further details.

Dismantling the early type thumb throttle is relatively easy (check out this post for more information) but dismantling the twist throttle is a bit more involved.

Alan
 

[Tommycat]

I encountered the same issue as I run a 52 volt nominal volt battery with a 48 volt rated throttle.

See some of the thoughts I had, and actions taken here...
Dreaded LED display out of voltage range.

But as mentioned by Bikemad in one of his links, these type LED displays where meant for lead acid batteries and seem very inaccurate. Though with use and in the correct range of operation. You can learn somewhat where you stand charge wise...

As such, my recommendation would be to procure a new throttle with a voltage meter. (or any voltage display for that matter) Using the potential voltage reading as a more accurate way of determining battery state of charge.

[Meridaman]

>>>As such, my recommendation would be to procure a new throttle with a voltage meter. (

Do you know if this can work properly ?
https://www.amazon.com/Dewin-Scooter-Throttle-Battery-Accessory/dp/B07K75HP8Y

thanks

[Tommycat]

According to the specs, it looks like it would work well as a voltage display for your 48 volt nominal battery and throttle. (hall sensor type)

But it would be necessary to change the connection(s). I would verify the wiring colors inside your current throttle as to their purpose. And reuse your existing HIGO connector and cable all the way into the new throttle, replacing the new throttle wiring harness and connectors.
Or you could just splice away, or add connectors, ETC.

Also note that you will lose the ability to turn on battery voltage accessories (IE: LED lighting). As your replacement candidate has no switch.

Just in case you haven't seen this yet...

 



Regards,
T.C.

[Meridaman]

Hello.
I bought that item.

>>> I would verify the wiring colors inside your current throttle as to their purpose.

It seems it's quite impossibile to associate color with numbers of the diagram.
Anyway...assuming black = ground, I succesfully identified with a meter the + 5V and the battery voltage ( + 54 approx full charged ).
I connected them and it works, the voltage is correctly showed. 3 cable of 4 succesfully identified.
Anyway, the throttle connection is remaining : the new throttle button has 1 only cable remaining (total 4) , the original controller has 2 ( one for throttle and one for light ). How can I identify it ?
Trying random... may I make damage ? Anyway, with the meter....1 cable is 0 V  and the other is something like 1,5 / 1,8 V....which one is the throttle ?

Thanks

regards

[Tommycat]

The lighting feed wire (pin #4 throttle connector) goes to the unterminated RED wire in the bundle at the upper wiring harness.
Just a reminder that these wires should be properly insulated off if not already done so.


 

As discussed here...
https://electricbike.com/forum/forum/builds/ebike-building-directions/48457-1st-build-e-bike-rider-magic-pie-v5-rear-bottle-batt-52v-11-5ah-huffy-parkside?p=64253#post64253

So if you don't have a light connected, I would say your light wire would be the 0vdc one, and the throttle the ~1.5 one.
Again, if no other device is connected to the RED lighting feed wire, and you didn't wire in a power switch to it. You could safely try each one to verify which one works.

[Meridaman]

It's done !
So, here is the final wiring :

New throttle device w/voltage meter ---> genuine Magic PIE 4

black - black ( ground )
red - white ( +5V )
yellow - orange ( battery + / realtime voltage )
green - green ( throttle signal )
not present - brown ( lighting )

[Tommycat]

Job well done. Glad to hear. Thanks for reporting back with that and the wire colors.


Cheers!