How to add more torque to my eMotorcycle

[Akore]

I have a Energy Motion 3000 watt motorcycle that I would like to add more torque to it for climbing the steep roads here. The rear motor works fine for just me but if I have a passenger and goods on the bike with me it struggles to climb. Was thinking about adding a second 3000 hub motor to the front of the motorcycle.

 

[Chalo]

If the motor doesn't get hot now in normal use, then the easiest approach would be a controller that delivers more current (amps) to the motor.

When you have a passenger or a lot of cargo, the weight bias shifts rearward, so putting a motor in the front wheel isn't a good idea for that condition.

 

[Akore]

If the motor doesn't get hot now in normal use, then the easiest approach would be a controller that delivers more current (amps) to the motor.

When you have a passenger or a lot of cargo, the weight bias shifts rearward, so putting a motor in the front wheel isn't a good idea for that condition.

It has gotten hot with a passenger on it with me but only after traveling a fairly long distance and going up some steep inclines. It has thermal protection and has shut off on us about 3 times.

 

[Chalo]

It has gotten hot with a passenger on it with me but only after traveling a fairly for distance and going up some steep inclines. It has thermal protection and has shut off on us about 3 times.

Sounds like you need a more powerful motor and controller, and likely a more powerful battery too.

 

[Akore]

It has a 72v battery tied to the 3000w motor. Not sure about the controller.

 

[Chalo]

It has a 72v battery tied to the 3000w motor. Not sure about the controller.

The voltage of the battery is unrelated to the current (how many amps) you can get out of it. If you want more power, you'll need more amps. That means a higher amp controller, plus a battery that can supply enough amps (which is a detail we don't know about your battery), and a motor that can use that much current without getting overcooked.

 

[Zambam]

What kind of battery do you have? I have a similar form factor "E motorcycle" bought with a 60 V 20Ah sealed lead acid battery. https://www.flyebike.com/product-pa...2PxyZeHkbPohh3m4SFD9VjcOnrnoo02p5M20FRApB0PKO

Battery died due to not keeping charger on it over the winter and the alarm system ran the batter dead. Took me around 8 months trying to get a battery for it. Ended up building a 22S 30Ah LFP battery for it which upped the voltage to 73V fully charged (lead acid fully charged was around 65V). With the LFP cells and higher voltage, it was transformed! Before, it was dangerously slow in car traffic, no acceleration, voltage sagged badly, top speed not more than 25 mph. With the 73V LFP battery, I can now beat cars from a stop light, top speed increased to 40 mph!

Great for errands since it can carry so much. Yesterday I took this 80 lb 4 spd manual transmission to the recycle yard and return a 50 oz Softsoap at Target afterwards. How many ebikes can do that?

Runs great but looks ugly. I am planning on removing the rusty chrome rails and paint them with gloss black enamel.



G

 

[Akore]

Mine also came with sealed gel batteries which died about a year after buying the bike 2nd hand so I was expecting them to need replacing. I sent it back to the dealer and had them put in a Lithium battery and swap out all the light for LEDs and replace the alarm. The alarm lasted about 6 months . I will try and get to the label on the battery to post here. Also I believe that the controller box is programable so while I have it apart I will try and get the info off of it as well. Your pic with the transmission reminds me of when I hauled compression stone in a 5 gallon bucket over several trips to fill my shed floor so that later it would be ready for the cement floor to be put in.

 

[Akore]

Got it apart to take photos:

 

[Chalo]

According to the specifications for the battery, 80A is the maximum discharge rate. So if you want more power, you'll need more battery.

Batería de Litio para Moto Eléctrica 72 V - 30 Ah - Tronex TES

Tipo: Li-ion Voltaje: 72 V Capacidad: 30 Ah Dimensiones: 300 x 220 x 180 mm Peso: 15,5 Kg Conector: Descarga: Celda 1C, max 3C PACK < 60A, pico max 80A.

tronex-tes.com

 

[Akore]

There is space under the floor board where there were 3 gel batteries (there were 6 total before) so I could add a second battery in parallel but I would still need a new controller?

 

[Chalo]

There is space under the floor board where there were 3 gel batteries (there were 6 total before) so I could add a second battery in parallel but I would still need a new controller?

You would need a more powerful controller (or a second controller, if you add a second motor). And if you use your original motor, you'll hit its thermal limits much more quickly that way.

 

[Akore]

So basically copy what I currently have to the front tire.

 

[Chalo]

So basically copy what I currently have to the front tire.

It will skid under load and on steep hills. Be sure you're okay with that before you throw money at making your scooter into a problem. When you add a battery, maybe put it up front over the second motor to help traction. Also work out your torque retention, because front hub motor problems are more dangerous than the same problems in the rear wheel.

 

[Akore]

Second battery would go here below my feet more towards the front and lower than the back battery so it should hopefully work:

 

[Chalo]

I don't see an obvious way to fit a hub motor to that fork. The fork requires a through axle, which isn't a feature you'll find on a 3kW hub motor.

 

[Akore]

I don't see an obvious way to fit a hub motor to that fork. The fork requires a through axle, which isn't a feature you'll find on a 3kW hub motor.

I remember seeing a add-on kit that attaches the motor to the brake rotor. I wonder if that would be enough to give it a little more uummff?

 

[gromike]

80 amps at 72v, what your controller is listed as, should move you pretty well depending on the battery. Though the controller is probably programmed for less amps by the scooter's manufacturer.

 

[Akore]

It actually does move myself around very well. I live in the Andes mountains so we have lots of steep roads. When a passenger is on with me it struggles depending on the incline of the road. I would definitely like to know what the controller is programmed to but unfortunately the Energy Motion company in Medellin is no longer around.

 

[Zambam]

How old is the battery? How much use on it? Do you have a voltmeter hooked up to the battery so you can see the voltage while riding? If not, get one. It will tell you the amount of voltage sag and your next course of action.

 

[offGridDownUnder]

72v battery tied to the 3000w motor

A way of thinking about this...

A small stream that flows at 72 cm per second.
A large river that flows at 72 cm per second.

The speed of the flow is the voltage (this is not correct*, but see below).

The volume - the "flow" - of the water is the amperage.

The river is flowing much more water, and represents much more energy.

Your battery must be able to supply the flow, your controller must be able to pass and control the flow, your motor must be able to withstand and use the flow. The motor will move quicker at the higher voltage, but if enough power (amperage multiplied by voltage) is not supplied then the machine will not go.

*In fact, voltage is more like pressure than speed of flow, but I hope the above idea gives you a way to think about your situation.

 

[Akore]

How old is the battery? How much use on it? Do you have a voltmeter hooked up to the battery so you can see the voltage while riding? If not, get one. It will tell you the amount of voltage sag and your next course of action.

June of 2020 it was put in. Used very little as we only go down to town and back once a week on it (4k round trip) and we took it on a few longer rides of about 16km maybe 12 or so times over the past almost 5 years. I will look into getting one of those voltmeters hooked up to the battery on Amazon so I can watch it, thx for the tip.

 

[Zambam]

Resist the temptation to get one with a color display, they are much less legible under sunlight. Get one with a monochrome LCD. Something like this one https://www.amazon.com/gp/aw/d/B093KTM1PS/?_encoding

 

[Akore]

Resist the temptation to get one with a color display, they are much less legible under sunlight. Get one with a monochrome LCD. Something like this one https://www.amazon.com/gp/aw/d/B093KTM1PS/?_encoding

Thank you for the link! the monochrome LCD was the only one with free shipping (with purchase of $35 or more) here to Colombia so I grabbed it and a few other items that I was in need of. Will report back once it arrives and I get it installed and tested.

 

[bananu7]

I agree with previous posters that in this case, the vehicle is pretty balanced as is. Adding the front motor would add weight and might be problematic for cable routing, extra battery, extra weight in the front wheel etc. If the rear motor is already getting hot, you'd need a new wheel with a new motor, a new battery and a new controller. At that point it's likely the brakes might be too weak, and the frame might be flexing too much.

In this case, getting a more powerful bike (or, likely more fun, a second scooter for your pillion) sounds like the best move forward.