Power of a 250 w LIME Motor

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omadawn   10 W

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Power of a 250 w LIME Motor

Post by omadawn » May 16 2019 10:06am

Hi Guys
A simple newbie Tech question:

LIME scooters get up & go easy on high slope ramps with a 250 w power...
However, on our personal scooters manuals there is always the indication that it´s not suitable for slopes bigger than 15%...

Mine has a 400 w Motor and even so, the recommendation is the same...why?

thanks

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cal3thousand   1.21 GW

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Re: Power of a 250 w LIME Motor

Post by cal3thousand » May 16 2019 10:31am

It could have something to do with the disparity in motor ratings. Manufacturers tend to bend the truth sometimes. Your 400 W could be a peak rating while Lime's could be a continuous rating of 250W. Another thing, being rated for public use, I'm sure they don't want to seem like they have too much power (for legal reasons).

If you can peak up to 400W, but say are generally limited to a continuous output of 200W, yours will start up the hill decently and then start losing.

Who rated your scooter at 400W?
Get a Cycle Analyst and a Multimeter, you're still a noob if you don't have at least one of each.

Planning on posting questions or buying anything on this site? Put up your country (at minimum) on your profile. This is a worldwide forum and we haven't reached clairvoyance.

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 16 2019 1:18pm

The watt rating is really dependent on heat. Most motors can go way, way over their rated power for a short burst. Climbing a 15% grade for over a mile is another story. The motor will likely overheat and fail. The weight of the rider and outside temperature, wind, etc. all have an effect on heating.
"One test is worth a thousand opinions"

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omadawn   10 W

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Re: Power of a 250 w LIME Motor

Post by omadawn » May 20 2019 10:58am

fechter wrote:
May 16 2019 1:18pm
The watt rating is really dependent on heat. Most motors can go way, way over their rated power for a short burst. Climbing a 15% grade for over a mile is another story. The motor will likely overheat and fail. The weight of the rider and outside temperature, wind, etc. all have an effect on heating.
So, one can say that for a motor of 200/250 W continuous power, climbing a 25% grade for...let's say 0.1 mile won't hurt the motor as long as it won´t get too much heat?

thanks

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 21 2019 1:05pm

omadawn wrote:
May 20 2019 10:58am
So, one can say that for a motor of 200/250 W continuous power, climbing a 25% grade for...let's say 0.1 mile won't hurt the motor as long as it won´t get too much heat?

thanks
Yep. I'm sure it could take 1000w for a while as long as you never overheat it.
"One test is worth a thousand opinions"

flat tire   1 MW

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Re: Power of a 250 w LIME Motor

Post by flat tire » May 21 2019 1:11pm

No, you can't make any rules of thumb like that whatsoever. It will depend on a ton of factors like how fast and efficiently the motor is running, how heavy the rider is, what the effective reduction is, how hot it is, whether there's mud on the motor...

Use your head guys.

Ianhill   1 MW

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Re: Power of a 250 w LIME Motor

Post by Ianhill » May 21 2019 5:38pm

Theres the i2r losses that build heat up in the core with eddys that increase with voltage, so theres a voltage limit to a motor if we exceed this and rev it to its vmax then it can either overheat or self destruct with high rpm.

Then theres the start stop overcurrent failure that allways ends up in a meltdown, the voltage range is not exceeded but the continous current handling is so the core slowly gathers heat faster than it can expele it and this is what happens to most rides climbing a steep hill or constant stop starting at full power with no thermal overload the motor is far from its no load rpm so its struggling less bemf to limit the current draw and it becomes controller dependant in weather the motor will survive or not

So if the motor struggles up a hill at full throttle no where near no load rpm theres heat gathering fast same for lots of full blast start stoping but inclines are the killer no doubt and prelonged climbing needs to be done under the rms of the motor or heat will gather.

I did have a 48v 1600w scooter that run cooler at 60v due to the gearing it was struggling at 48v and got no where near no load so got hot on lead acid swapped it to 60v 4.4kw lipo and got simular heat output due to not struggling to get top speed much closer to no load speed more bemf and the motor sang at 7rpm rather than under 5k it would hold this for 20 mins carry 70kg at 35mph average top out at 48 mph so rides can be improved if theres meat on the bone been left with poor implemention of a motor, now all the scooter run a simular setup and called the black widow i made mine good 5 years ago now thing was a rocket and the dualtron thunder steals the show with 70mph top speed if you dont like the look of your bones.

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Re: Power of a 250 w LIME Motor

Post by billvon » May 21 2019 6:38pm

Ianhill wrote:
May 21 2019 5:38pm
I did have a 48v 1600w scooter that run cooler at 60v due to the gearing
Sorry. The motor may well have run cooler for a great many reasons, but it was NOT because you increased the voltage. When a motor hits its base speed its current goes down. Higher voltage = higher base speed, and at a higher base speed you need more power to maintain a given speed. Which equals more heat.
--bill von

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Re: Power of a 250 w LIME Motor

Post by Ianhill » May 21 2019 8:12pm

billvon wrote:
May 21 2019 6:38pm
Ianhill wrote:
May 21 2019 5:38pm
I did have a 48v 1600w scooter that run cooler at 60v due to the gearing
Sorry. The motor may well have run cooler for a great many reasons, but it was NOT because you increased the voltage. When a motor hits its base speed its current goes down. Higher voltage = higher base speed, and at a higher base speed you need more power to maintain a given speed. Which equals more heat.
If the gearing is too hard the motor will struggle create heat and burn out over a long extended climb i physically could not touch the motor of a stock setup scooter.
Swapped controller to 60v, 16s lipo and doubled the current to 60 batt amps same hill much cooler and i travelled up in half the time with the motor singing much closer to its no load rpm sounded much eaiser to it with less heat generated at the top felt cooler i still had finger prints remaining, i also drained a 1kw pack at full throttle on varied tarmac terrian climbing etc and the motor was cooler than it was stock 48v 1600w lead acid crawling up hills barely half its potential rpm.

I do get what you mean i could have made the gearing easyier or raised the current if the kead acid was not tapped out and got simular effect of a cooler motor but with a lower top speed and the lower volts means less IR losses at the same current and a even cooler more efficent energy wise motor but the speed potential was there the chinnese had left meat on the bone withbit being a 48-72v motor so as thread title can you get that little extra power ? sometimes you can get a whole lot more and sometimes theres not a thing left the bones are smashed and splintered lucky my scooters motor was 48-72v so there was room to improve not all rides have such potential to raise their throughput and live to tell the tail.

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 21 2019 10:05pm

What I've observed with my A2B is simply by going faster, the increase in wind cooling on the motor more than makes up for the additional needed power. 10mph seems to be the point where it will maintain allowable temps. If I go any slower for any length of time climbing a hill, the motor overheats.
"One test is worth a thousand opinions"

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Re: Power of a 250 w LIME Motor

Post by Ianhill » May 21 2019 10:32pm

fechter wrote:
May 21 2019 10:05pm
What I've observed with my A2B is simply by going faster, the increase in wind cooling on the motor more than makes up for the additional needed power. 10mph seems to be the point where it will maintain allowable temps. If I go any slower for any length of time climbing a hill, the motor overheats.
You must of done some serious mileage on that hub now, i still got my metro it needs a new owner i got to many rides and projects, ill sell it cheap to someone that can make use of it and enjoy the hobby its a new ride in all fairness very comfortable with 34mm stantion front shock from factory fairly strong front end just some peoples frames crack ive got no signs of this but keep an eye on the swing arm i done dual torque arms and centrlized the hub to try even the loading, stock the rim is offset for the 7 speed cassette i got rid of that and went single speed got a straight chain line same time but no gears at all just peddle throttle or regen and im proberly the only one using a mxus 3k at 36v and 40amp lol but getting upto 30 mile with the stock 350wh pack if i put the effort in.

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 22 2019 8:10am

Ianhill wrote:
May 21 2019 10:32pm

You must of done some serious mileage on that hub now, i still got my metro it needs a new owner i got to many rides and projects, ill sell it cheap to someone that can make use of it and enjoy the hobby its a new ride in all fairness very comfortable with 34mm stantion front shock from factory fairly strong front end just some peoples frames crack ive got no signs of this but keep an eye on the swing arm i done dual torque arms and centrlized the hub to try even the loading, stock the rim is offset for the 7 speed cassette i got rid of that and went single speed got a straight chain line same time but no gears at all just peddle throttle or regen and im proberly the only one using a mxus 3k at 36v and 40amp lol but getting upto 30 mile with the stock 350wh pack if i put the effort in.
I don't ride it much these days as I mostly use my other bikes. The Metro motor was "rated" at 500W and peaked around 750W in the stock configuration. I run mine a little over 2kW, so nearly 3x the rating. With the 1kWhr rear pack, I can ride till my butt hurts if I stay under 20mph.
"One test is worth a thousand opinions"

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omadawn   10 W

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Re: Power of a 250 w LIME Motor

Post by omadawn » May 24 2019 1:46pm

Ok guys,
very nice to see such an interesting discussion on this topic, always great to learn from you!

Now let´s get practical on my initial subject, if you please:

the million dollar question: My new 500W brushless motor, and 24V lithium battery e-scooter, ridding on with a slope, let´s say 30%. Concerning only on the behavior of the scooter, what can be a good indicator that the motor is definitely overheating?

thanks

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 24 2019 4:25pm

You can’t really tell from the riding behavior until it fails. It might slow down a bit. A temperature measurement is really the only way.
"One test is worth a thousand opinions"

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omadawn   10 W

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Re: Power of a 250 w LIME Motor

Post by omadawn » May 25 2019 5:46am

What's to be expected when a motor fails for the first time? then it will lose performance? And what about the battery?

Thanks

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 25 2019 3:05pm

Like you suddenly lose all power and smoke comes out somewhere. The battery may get shorted but the BMS is supposed to protect it.
"One test is worth a thousand opinions"

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omadawn   10 W

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Re: Power of a 250 w LIME Motor

Post by omadawn » May 27 2019 10:34am

In a way of conclusion one can say then:

In order to minimize the risk, For slopes higher than 15/20% keep it short on the distance. Right?

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 28 2019 1:55pm

omadawn wrote:
May 27 2019 10:34am
In a way of conclusion one can say then:

In order to minimize the risk, For slopes higher than 15/20% keep it short on the distance. Right?
Right. The motor can take way more than the rating for a short time. A really good setup is where the motor has a temperature sensor that automatically reduces power to keep it below the max allowable temp.
"One test is worth a thousand opinions"

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omadawn   10 W

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Re: Power of a 250 w LIME Motor

Post by omadawn » May 28 2019 3:00pm

Just for the record that controller device has a specific name?

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fechter   100 GW

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Re: Power of a 250 w LIME Motor

Post by fechter » May 29 2019 8:17am

More advanced (expensive) controllers have this feature built-in. Cheaper ones have a thermostatic switch that just kills all power if the motor reaches max allowable temperature. But most motors don't have temperature sensors built in, you have to add them.

Something like the CycleAnalylist can be added to most systems and do the automatic power roll back for temperature. But it costs about as much as a new motor, so may not be worth it on a small scooter.
"One test is worth a thousand opinions"

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omadawn   10 W

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Re: Power of a 250 w LIME Motor

Post by omadawn » Sep 28 2019 2:28pm

Ok, I am wondering if Overvoltage (36 V ?) can be an option for me in order to provide more power on climbing slopes, with a new controller having the temperature sensor to be installed in the motor...

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Re: Power of a 250 w LIME Motor

Post by Ianhill » Sep 28 2019 3:31pm

omadawn wrote:
Sep 28 2019 2:28pm
Ok, I am wondering if Overvoltage (36 V ?) can be an option for me in order to provide more power on climbing slopes, with a new controller having the temperature sensor to be installed in the motor...
Definatly an option if the incline is a small percentage of the ride and there's temp sensing, get the temp probe under the end turns thats where the heat builds from bursts of overcurrent( beyond continuous power and in the realms of peak power where motor destroying heat will build)

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omadawn   10 W

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Re: Power of a 250 w LIME Motor

Post by omadawn » Sep 28 2019 6:32pm

if the incline is a small percentage of the ride
Normally when it comes to slopes its quite more, close to 50 % of the ride....but I can always make stops, and climb with slower speed...

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