Improper Fan curve

In owning the scooter for almost 22 months now, I have noticed the Fan curve (fan running speed) is completely useless, it runs extremely at high speed or it doesn’t run at all it’s a DC fan with a fixed voltage, but completely not aligned with the temperature and speed of the scooter.

Consider the scenario you are going in extremely slow traffic, with you giving very slow to medium acceleration which in turn causes the motor to heat up very quickly, or unevenly, with no airflow because the fan only turns on when you ride over 15km/hr and that too at full speed.

Scenario 2. if you are going at a speed over 40km an hour the wind will automatically cool the motor considering that the air is not blocked by any object kept in front or has a dusty vent, there is no use of it running it at full speed it can be turned on at when the scooter stops moving.

All I wanted to say is that the coding needs to be in alignment with the temperature of the motor, it’s now designed to save the range, but in reality, it needs to be saving the motor from overheating. All the factors of speed, range, and temperature must be taken into consideration, if the temperature is high the fan should not stop when the scooter comes to a halt, and if the temperature parameter is low it doesn’t need to turn on at all.

Right now it turns on irrespective to ride style, it turns on as soon as I give acceleration and stays on, and even I know I’m going above 50km/hr it’s still on? and it turns itself off as soon as a halt, it’s drastically reducing the life of the motor and range not to mention a loud noise it causes

@tarun I usually don’t tag the CEO of the company, but this is something that the coding can be corrected and updated for all 450, 450x, 450+


I’ve observed that the motor heats up a lot at high speeds. Maybe wind dosent hit the motor cuz its way too in? I’m thinking of adding a water cooling system or fins to the rotar maybe.

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The motor in both 450 and 450x/+ solely depends on the fan for cooling, even the temperature sensor is placed at an awkward position, there are vents beside the fan grill but now made me think that they are just a showpiece and does not provide any incoming wind cooling

Adding more fins is a near-impossible job, but water cooling copper pipes can be added by rotating around the motor and powering the pump using the existing fan’s power. (just my thought), a PC’s 120mm or 140mm single radiator may be the solution?


The fan is a joke. It’s mounted overhead of the motor in a push configuration and instead of venting effectively, tries to push rising heat back down. The control is a simple binary output that triggers at a temperature setpoint or 3000 RPM motor speed. There is no PWM controller to vary it’s speed smoothly.

As if this wasn’t sufficient, there is an internally well known defect but externally seldom acknowledged that the fan itself has major balance problems. Hence the vibrator effect.

Apparently, the motor controller does derate the output depending on temperature, so even running with the fan unplugged won’t cause any failures.

The solution is obvious: use ram air cooling by ducting air from near the front mudguard to the motor cavity. The faster the motor spins, the more headwind is available to properly cool it.

Words fail to describe how stupid that fan solution is.

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Wouldn’t this drive all the mud and slush from the front, right into the motor housing?

Would a vent right below the seat help (above the existing vent window?

The motor is built to operate even when submerged. As it is, it picks up all manner of crud when riding on slushy roads.

The inlet can be positioned away from the path where the tire flings dirt. After that, a tube needs to run the length of the scooter and twist before it enters the motor cavity, acting as a baffle for any incoming debris.

With fast, pressurized air being force fed from the bottom, one can delete the fan and the resulting vent will evacuate hot air pretty effectively.

Ram air cooling is a brilliantly elegant solution, which I will work on after the festival excitement sorts itself out.

shouldn’t it should be that way? if it’s a pull configuration then it will blow all the hot air from the grill right on the legs.

Yes, I noticed that from day 1, it’s a balance problem that comes because of improper mounting solution (3 awkwardly positioned mounting holes)

Cannot have the boost of air that an Air-Ram cooling requires, the force will be completely inadequate

We should all join the Ather development team :upside_down_face: but that won’t be the solution because they listen from one ear and spit it out from the other

do take photos

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It’s a toss up between whether you want warm air on the crotch or evacuate heat effectively. I would prefer the latter. Also, there is a little bit of seat overhanging the vent, so it should diffuse any hot air pretty quickly.

I gave them the motor rubber mount idea for free. It was like casting pearls before swine, and came with the added bonus of warranty threats. Literally, the only annoyance after I quieted the motor down is this fan which kills the refinement when it kicks in.

I’m not going to try and educate them anymore.

I’ll try.

I like it nice and cold thank you very much, If anyone remembers the older activa 3g and before there is the engine fan which blows skin burning hot air right on your left leg. Ather is not wrong in this configuration. even though placement correction is needed

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LOL. Trying to push heat back against convection at an object that’s trying to dissipate it isn’t wrong?

it is, here is the way


^ This is the most effective direction of airflow to properly evacuate hot air. Trying to force it in the opposite direction is a waste of energy, requiring a big, fast, loud fan and unnecessary juice from the battery.

As far as your concerns about hot legs go, a Splendor engine dissipates more heat than this, and it’s barely felt even though your shins are right next to the engine block and exhaust. A 3kw electric motor and its controller won’t even come close to dissipating that amount of heat, and there’s plenty of stuff shrouding that vent for the warm air to come anywhere close to one’s body.

Ascertaining this is simple enough. Just disconnect the fan and go for a small ride. See if you can feel any heat.

Mixed(Forced+Natural) Convection is the phenomenon by which heat is being disspated from the motor.(I’d like someone to educate me about how battery heat dissipation works). image

What the Team at Ather has done is shown in part (b)[opposing flow] of the above figure.


As seen from the graph [reference/DOI: 10.1115/1.4032499], opposed convection is seen to give greater numbers of wall heat fluxes than aided convection.

I’m unsure now, because, @blackworks says unplugging the fan gives a better feeling of heating dissipation :smile:

There is thermally conductive wax or something similar in the battery casing that is normally a solid. As the heat rises, it melts and flows towards the bottom of the casing, which is visibly ribbed on the outside to act as a heat sink. There is a small airgap between the lower casing and the plastic sheet at the bottom through which air is forced as a result of vehicle movement, cooling the battery pack.

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I’m interested to know how you smoothened the motor…the rumbling at 50-55 is so jarring! Is there a thread you’ve put up with the details? For the motor cooling, wouldn’t flipping the fan’s power work better and be the least complex way to go about it? If it does cool better this way, the fan shouldn’t turn on as often.

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I will get to writing about it in time. Putting it off because I don’t have any usable pictures.

When I get time to take the scooter apart again, I’ll try to take some detailed pictures.

The solution involved taking out the mid-frame base on which the motor is mounted, milling it on the sides to create a gap between it and the rest of the chassis, then some drilling and welding on sleeves to accept rubber bushes that act as vibration dampers, then putting the whole setup back together and aligning everything properly.

It’s not something simple that an end user could attempt at home, but the company could very easily update their part design and make it happen. It’s quite clear that they aren’t interested.

Fan blade angles are optimised to effectively move air in one direction. If you try flipping the polarity, the motor won’t care, but the blade geometry will. Flipping the entire fan upside down might probably work better, but the terrible vibration issues on it make me want to throw it out completely. I’m guessing the bearing on that thing is either cheap junk and / or not designed to work at an angle other than perpendicular.

The fan is programmed to kick in at 3000 RPM motor speed no matter what the actual temperature. What you say will only be noticeable when one comes to a stop after a hot run.

damn! I’ve faced this. please correct if my observation was wrong the vehicle starts to oscillate left and right after riding a bit aggressively. it feels like the tyre pressure was low and vehicle loses it’s balance

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Not sure what exactly you mean. The front end being lighter than the 450 contributes to a squirrelly feeling, and it’s made worse by the crappy tires that come with the scooter.

The air blown over the motor is nowhere enough for you to get burnt or feel it much especially when the vehicle is moving is what I feel.

There are super smooth fans available in market. We could probably find a size match and replace the crappy OEM fan.

Can we not modify the motors pully with tiny fins so that it keeps circulating the air? I have not dismantled my vehicle because of warranty concerns. Someone who has dismantled the vehicle should confirm @blackworks .

With your rubber mounts to the motor and smoother fans with rubber bushings (for both motor and dashboard) should eliminate all kinds of vibration except for the drivetrain vibrations which are minimal in dry conditions.