Will this motor be strong enough for my project?

Short description : I bought a scooter and I want to make it electric. So I decided to add an electric motor.
I have the whole plan made, the only problem for now is that I don't know how strong the motor should be.
I want to reach at least 30km/h (~12.5 miles/h).

Will this motor be good enough :
https://www.amazon.co.uk/gp/product/B01LQ45X3W

After seeing the replies, this is the new motor I decided to get :

Also, I'm going to use three 12v 9Ah acid batteries connected in series : http://www.cel.ro/acumulatori-ups/acumulator-ups-kstar-battery-12v-9ah-pMiU6NjMp-l/
(The page is not in english so you will have to translate it)

I appreciate any comment guiding me on the right path.
Thank you!

I'm not a mechanical engineer, so I'm guessing here. I don't think the question of "is this Motor strong enough" can be answered given the Information provided.

How strong a Motor is is usually measured in torque. The Motor of a small toy electric car can probably do 20.000 RPM but it simply doesn't have any torque. Maybe there is a way of calculating something based on some of the other data, but I doubt it.

The other Thing is, you have said nothing about any type of gearing you are going to do. What does the drive chain look like?

A 900W motor is more than 1 horse-power in old money so it is plenty strong enough to do damage and cause serious injury.

It seems to be a high-speed motor as 50,000 RPM max is mentioned. What is the motor intended for? You really need to get the manufacturer's graphs showing how power and current draw vary with speed.

What RPM will you need for your road wheels when traveling at 20kph? You will need to gear the motor down suitably - but probably not from the max.

You will also need a pretty hefty battery to provide 69 amps for any length of time.

I think that the motors in electric bikes and that sort of thing are designed to produce their max power at much lower speeds so that less reduction gearing is required.

...R

Its probably powerful enough, but its stupidly fast for any plausible transmission
system on a scooter. At 50,000rpm its going to wear out its own bearings really
quickly (remember this is a motor for RC models, not daily commuting, and it
not designed for a long service life). 50,000rpm is also screamingly loud and annoying,
think dentists drill or jet engine.

Something around a kW or two, designed for a higher voltage (36, 48), and speed
around 3000 to 5000rpm would be much better match. That would mean a torque
of several Nm, and a single stage of gearing (or sprocketing) to match the wheel
rpm.

You also need a motor designed to survive the conditions, ie bearings must be sealed,
and the motor itself weatherproof.

Higher supply voltage means the power cables can be a lot thinner (20A is much
easier to handle than 60A)

You should probably explain more about the donor scooter, mass, intended top speed,
transmission type, wheel size, existing motor specifications...

I have one of those 3650 sized motors in a 1/10 sized rc truck that weighs about 15 pounds. Even though it can handle a high current it will get screaming hot, it even gets warm with the rc truck! You will need serious cooling Like a water jacket or big fins and a fan for that motor if you want to use it for more than about 20 amps continous. The can design of the motor has no airflow and builds heat very easily.

There are other winding options for the 3650 sized motors for a lower Kv but I would say it would be a little bit undersized to move a human sized mass.

Something like this maybe

@MarkT Can you recommend one?
I want the scooter to be able to reach at least 20km/h and to carry up to 90kg (including his weight)

@alka That's a really nice motor. The only problem is the battery. I need a 36v battery.
I can connect 3x12v batteries with 3Ah in series but if I'm right, I will be able to run the motor for only 4 minutes at max speed.

softt:
I can connect 3x12v batteries with 3Ah in series but if I'm right, I will be able to run the motor for only 4 minutes at max speed.

That just means you need more battery capacity. There is no way around that.

Use Google to do some research on the sizes of motor and battery used in electric bicycles.

...R

I want to make my own electric scooter and I found a pretty powerfull motor. It requires 36V and 52A to run at full speed (1850W).
Buying lipo batteries would cost me a lot of money to have a decent run time. So I decided to go with car batteries. I will buy 3 car batteries with 10Ah and 12v. Connect them in series and be happy.
Is this a valid solution to my problem?
Thanks!

Sure. The scooter will be pretty heavy, though...

aarg:
Sure. The scooter will be pretty heavy, though...

Good to hear that.
On the motor page, inside the specifications list, it is mentioned the fact that it can run with 4-12s lipo cells. Why exactly is that?
That information made be in doubt.

Do you mean 4 off 12s lipo cells -> voltage about 16?

Or 4 - 12 s LiPo cells -> voltage 16 - 48?

Allan

900W @ 50000 RPM, torque is only about 0.17 Nm, you'll need a 50 to 1 gearbox.

And no battery will deliver it's rated AH if you try and discharge it in 4 minutes - that's 15C. You might get 1/2 the rating if you're lucky and the battery is designed for such rates.

It'll probably get hot.

Allan

ps. I have a friend who fitted a chainsaw engine to a scooter - that went OK!

I think you will blow way past your 20km per hour speed if you do go wide open throttle. Thats 2+ horsepower!

But it was fun!

Allan

Can you elaborate on the car batteries?
Ive never seen a 10AH car battery.
Most are at least 60AH up to 100AH.
A 10AH lead acid battery will not supply 52 amps.
The normal maximum discharge rate for a lead acid battery is 1C, so 10 amps for a 10AH
battery.
Lithium Ion batteries would be much better.

softt:
On the motor page, inside the specifications list, it is mentioned the fact that it can run with 4-12s lipo cells. Why exactly is that?

A link to the motor page would help us to provide an answer. A link to your 10Ah 12V "car batteries" might help to solve a few puzzles too.

I would prefer not to have to guess what someone is talking about.

Steve

softt:
I want to make my own electric scooter and I found a pretty powerfull motor. It requires 36V and 52A to run at full speed (1850W).
Buying lipo batteries would cost me a lot of money to have a decent run time. So I decided to go with car batteries. I will buy 3 car batteries with 10Ah and 12v. Connect them in series and be happy.
Is this a valid solution to my problem?
Thanks!

Car batteries are entirely the wrong kind of lead-acid battery, since they are designed to produce 600A or more for brief periods, but otherwise always be kept fully charged.

You need deep-cycle sealed lead-acid batteries, which are designed for many deep discharge-recharge cycles.

Note that all lead acid batteries are quickly ruined(*) by over-discharge, so you will need battery management
unit to cut off before the battery goes flat. All lead acid batteries should be stored fully charged need regular top-up charge in storage.

(*)
Here ruin means the capacity drops to a small fraction of the nominal value and the internal resistance
increases dramatically.

Threads merged.

@softt, please keep similar / identical topics on one thread.

Look up electric bike conversion kits. 1000 watt for around 200.00 minus the battery.