Upgrade recommondation?

Dousi

1 µW
Joined
Aug 10, 2011
Messages
3
Location
Switzerland
Hi All
I've been registered here for a long time but never Posted. now I finally got my first E-Vehicle, wich is a Scooter from the Brand Twister. its a 48v BlDC 1800W with Chaindrive and lead batteries.
now, it does not feel like 1800w at all, and I want to change something to get more torque out of it.

what would be the best order to upgrade? what brings most? is this Motor Good at all?

I thought I'd start with the battery, put in a pack of 13s RC Lipos to get enough amps.

if this isn't enough upgrade the controller (suggestions?)
and last the motor.

whats on the list is a belt drive as well, to quieten the drive noise.

thank you for your help in advance!

best regards
Dousi
 
There's a lot of "scooters" of many types that come up under "twister"
https://www.google.com/search?q=Twister+Scooter
so you'll need to specify *exactly* which specific model it is, and from where. A link to the manufacturer page for your specific model would be best.

Otherwise we don't have any real info to base any advice on.


FWIW, a number of scooters I see under that name are advertised as "1800w" but clearly say they are 1000w when you look at the specs. Most use SLA batteries.
 
I did some reseaarch and could not find the "real" manufacturer.

this is the scooter I have:

TnaKQy1ttt2qXcZY6


Manufacturer is an Importcompany in Germany:
https://www.menila-b2b.de/product_i...scooter-crosser-x1-1800w-48v-10-zoll-eco.html

It has an CH12K05-A Controller 1800W and a CHD01-C BLDC Motor with 1800W, 5400rpm
Battery is a 48V 12ah SLA.

Yesterday I drove uphill and it was a very rough ride, as if the controller cant control fine enough for these "low" RPM I needed for the steep (10°) hill.

would a Kelly Controller help here? is a true Sinewave better for low rpm torque? It felt as if I can feel the controller switch from one phase to the other.

First thing I'm gonna do is change the chaindrive to belt and reduce the Reduction ratio to get more torque and less speed.

Is an SLA Battery even Capable to deliver the amps needed to generate enough torque?

great thanks for all your help!

Dousi
 
Dousi said:
this is the scooter I have:

TnaKQy1ttt2qXcZY6
Ah. Well that is the same one I see listed as only 1000w motor in a number of places, even though it is listed as an 1800w scooter. They don't specify the controller at all, though, so it could be 1800w.

But until you put a wattmeter on it, and measure what it actually uses, I wouldn't really believe it. You can get cheap ones; there's a number of threads about wattmeters that will help you find the best one for your needs. That's the first thing I'd actually do, so you then can figure out where other things can be improved.


It has an CH12K05-A Controller 1800W and a CHD01-C BLDC Motor with 1800W, 5400rpm
Battery is a 48V 12ah SLA.
FWIW, whenever you're actually using 1800w (if indeed this system is capable of it), you'll be pulling over 3C from those batteries (nearly 37A), which can be hard on little SLA. Most of them were tested at slow discharge rates of 1/20C, or 0.05C; this is what their capacity is rated at, meaning you will only get 12Ah at that low rate, and high rates like this will usually only let you get about half that capacity, at best. Then since it's bad for them to discharge past about 50%, you really only get about 1/4 their listed capacity, so it's like having a 3 or 4 Ah battery pack for all that space and weight.

They'll also generally sag a lot in voltage, so you wont' really be getting 1800w out of them (or else the current will increase, being even harder on them), so your speed drops when under that kind of load, sometimes quite a lot, and increasing throttle won't help.

Depending on the space you have available, something like RC LiPo might be the best option for high power...but lifespan is short, and there is more risk with it than with some other battery types (which don't have the same power capabilities, for the same size pack, however). What you end up with will be determined by the actual current and power needed by the system (which you have to measure under the worst loads, like the hill), your budget, your available space, and your willingness and ability to deal with risk (fire, etc) and DIY.


Yesterday I drove uphill and it was a very rough ride, as if the controller cant control fine enough for these "low" RPM I needed for the steep (10°) hill.
That usually means that the system is overloaded, unable to supply enough power to keep your speed and prevent overheating the motor and controller, and overstressing the batteries, if you can't keep up a high RPM to have at least 50% or more of the motor's unloaded speed. A couple of things can happen; the hall sensors, if the motor has them, can overheat and then the controller doesn't get correct position sensing, so it sends power to the mtoro with teh wrong timing, and it feels rough. Or the cheaper types of sensorless motor and controller can have troulbe under high loads and slower speeds with reading the pulses of the motor feedback and thus creating the right timing of signals.


If you have a pointable IR thermometer, you can measure the actual motor casing temperature, and controlller temperature, etc., at the top of the uphill ride, after having ridden around the same amount you usually would, where you see the performance problems.


One ohter thing that can cause a rough ride is if the battery voltage drops so much that it is below the controller's cutout. If it has a fast response time to it's LVC, it'll cut out, then the voltage will go back up, it'll turn bakc on and start running again, then immediately cutout from the load causing voltage drop, and cycle thru this until the load is removed (till you're not going uphill).





would a Kelly Controller help here? is a true Sinewave better for low rpm torque? It felt as if I can feel the controller switch from one phase to the other.
You'd get the same problem, if it's a sensored controller and it's overheating, or if the motor is that overloaded.

Before considering a Kelly, you should read around the forums for troubleshooting threads on that brand (and others, like Sabvoton, etc), to see the kinds of issues you may be getting into.

For low RPM torque, you need more power, if you mean low motor RPM. If you mean low wheel RPM, then more power, *or* lower gearing, so the motor spins faster for the same wheel RPM, and is more able to supply more power.

Sinewave isn't likely to make much difference there (sometiems it makes it worse with some controller/motor combinations). There are also several kinds of sinewave; some are true FOC that constantly calculate the motor waveform based on the motor's feedback, some are just lookup tables with a rough sinewave shape, that don't adapt to the actual motor conditions. Which one works better depends on the motor and condtions, but the non-lookup-table-type will require more information about the motor (inductance, resistance, kV (RPM/volt)), which if you don't have you'll have to measure, unless it has an "autotune" function to at least get you close. This is more complicated to setup, but usually works better once it is properly tuned.

The catch is that at low RPM, like especially from a stop, if it is a completely sensorless system, it may have trouble determining actual motor conditions since there's not enough feedback yet. Some of these use sensored start / sensorless run, and they work better (sometiems a lot better) at zero speed and low speeds, once the system is tuned.

If you don't want to deal with tuning, the lookup-table-type dont' need to know anythign about the motor, but they also don't adapt to motor conditions so may not work quite as well in some systems.


First thing I'm gonna do is change the chaindrive to belt
Before you do, make sure you look up some of the belt-drive type threads for various systems (not just boards/scooters), as there are some things to consider when sizing belts, sprockets, etc. For instance, you'll need a wider belt to do the same work as a narrower chain, probably twice as wide or more. Other considerations include bend radius for specific belts and types; tighter bends means faster wear and more problems. Tension is another issue.

and reduce the Reduction ratio to get more torque and less speed.
That might help with motor overloading, but if it still can't keep up enough speed on the hills, it'll still have the same problems there.
 
amberwolf said:
Ah. Well that is the same one I see listed as only 1000w motor in a number of places, even though it is listed as an 1800w scooter. They don't specify the controller at all, though, so it could be 1800w.

But until you put a wattmeter on it, and measure what it actually uses, I wouldn't really believe it. You can get cheap ones; there's a number of threads about wattmeters that will help you find the best one for your needs. That's the first thing I'd actually do, so you then can figure out where other things can be improved.

I have a wattmeter on Order, waiting for delivery to actually measure the Power it uses.

FWIW, whenever you're actually using 1800w (if indeed this system is capable of it), you'll be pulling over 3C from those batteries (nearly 37A), which can be hard on little SLA. Most of them were tested at slow discharge rates of 1/20C, or 0.05C; this is what their capacity is rated at, meaning you will only get 12Ah at that low rate, and high rates like this will usually only let you get about half that capacity, at best. Then since it's bad for them to discharge past about 50%, you really only get about 1/4 their listed capacity, so it's like having a 3 or 4 Ah battery pack for all that space and weight.

They'll also generally sag a lot in voltage, so you wont' really be getting 1800w out of them (or else the current will increase, being even harder on them), so your speed drops when under that kind of load, sometimes quite a lot, and increasing throttle won't help.

I did notice this Voltage sag a lot when driving for some longer periods of time. if its less than 1800w its not a problem for me, I just want good acceleration and hillclimbing ability with a speed of about 35km/h, it currently runs 50km/h wich I dont need.

Depending on the space you have available, something like RC LiPo might be the best option for high power...but lifespan is short, and there is more risk with it than with some other battery types (which don't have the same power capabilities, for the same size pack, however). What you end up with will be determined by the actual current and power needed by the system (which you have to measure under the worst loads, like the hill), your budget, your available space, and your willingness and ability to deal with risk (fire, etc) and DIY.

my problem is, that im not that inclined with batterypacks, so I'm not able to build my own unless I can bolt it together and dont have to solder or spotweld or whatever. I want to buy a pack that fits and works, if it means that I have to unplug the batteries to charge and balance them I would do it, thats not a big problem to me. If there is a better suitable solution that does not cost a fortune I'm ok with it.

That usually means that the system is overloaded, unable to supply enough power to keep your speed and prevent overheating the motor and controller, and overstressing the batteries, if you can't keep up a high RPM to have at least 50% or more of the motor's unloaded speed. A couple of things can happen; the hall sensors, if the motor has them, can overheat and then the controller doesn't get correct position sensing, so it sends power to the mtoro with teh wrong timing, and it feels rough. Or the cheaper types of sensorless motor and controller can have troulbe under high loads and slower speeds with reading the pulses of the motor feedback and thus creating the right timing of signals.

its a sensorless motor, and I expereinced with my small LIPOs I put in as a test that it did work better, less voltage sag and more power, so the battery was limiting here.

If you have a pointable IR thermometer, you can measure the actual motor casing temperature, and controlller temperature, etc., at the top of the uphill ride, after having ridden around the same amount you usually would, where you see the performance problems.

the motor and controller both got barely warm after my usual ride. maybe 45C. easy to touch, right after driving for 8km and up the hill on the end, guess that means that they are capable of more?


For low RPM torque, you need more power, if you mean low motor RPM. If you mean low wheel RPM, then more power, *or* lower gearing, so the motor spins faster for the same wheel RPM, and is more able to supply more power.

I'm aiming for both. I currently look into the belt drive to reduce the gearing ratio and upgrading the battery for more motor torque.

First thing I'm gonna do is change the chaindrive to belt
Before you do, make sure you look up some of the belt-drive type threads for various systems (not just boards/scooters), as there are some things to consider when sizing belts, sprockets, etc. For instance, you'll need a wider belt to do the same work as a narrower chain, probably twice as wide or more. Other considerations include bend radius for specific belts and types; tighter bends means faster wear and more problems. Tension is another issue.[/quote]

I'm a mechanical engineer, so I now how to find the right beltdrive, thanks for mentioning!

I mentioned that I bult a lipo pack with my turnigy 2200mah 3s Lipos. this is just as a test, and the motor worked better, as it had 44 amps to draw and less voltage sag. but still not enough to get up the hill in a good fashion.

what battery chemistry would you recommend? lifepo4 is a good chemistry but I cant build a pack myself and didnt find one for a resonable price. I have a space availabe of 220x320x110mm.

thanks again for your big help!!
Dousi
 
Dousi said:
.
I did notice this Voltage sag a lot when driving for some longer periods of time. if its less than 1800w its not a problem for me, I just want good acceleration and hillclimbing ability with a speed of about 35km/h, it currently runs 50km/h wich I dont need..
Then your best first bet is to change the gearing from the motor to the wheel, for a bigger gear on the motor or a smaller one on the wheel. That will give you more torque and less speed.

YOu can calculate the necessary ratio by first checking the ratio you have now, then multiplying that by the ratio of the speed you need vs that you have. 50/35 or 35/50, depending on which gear you're changing, is the ratio you would use to figure out the new sprocket size.

It's going to give you less wear on belt and sprockets if you change the smaller gear for a bigger one, if that is on the wheel, but if it's on the motor, you'll have to change the larger gear on the wheel for a smaller one, becuase the one on the motor is probably already the smallest you can use.


my problem is, that im not that inclined with batterypacks, so I'm not able to build my own unless I can bolt it together and dont have to solder or spotweld or whatever. I want to buy a pack that fits and works, if it means that I have to unplug the batteries to charge and balance them I would do it, thats not a big problem to me. If there is a better suitable solution that does not cost a fortune I'm ok with it.
<snip>
I mentioned that I bult a lipo pack with my turnigy 2200mah 3s Lipos. this is just as a test, and the motor worked better, as it had 44 amps to draw and less voltage sag. but still not enough to get up the hill in a good fashion.

what battery chemistry would you recommend? lifepo4 is a good chemistry but I cant build a pack myself and didnt find one for a resonable price. I have a space availabe of 220x320x110mm.
For a small space, RC Lipo is your best solution for high current from a small pack, as long as you can accept the risks of using and charging it.

If you have a large enough space available (probably not), used EV cells like Nissan Leaf modules easily bolt together, and can be had reasonably cheaply if you look around enough, especially if you have salvage yards in your area. AFAICR the Leaf modules are two cells in series, so the large bolt terminals are the main plus and minus, and the middle small one is the center balance tap. But it's kind of a large space you'd need. You can look up the dimensions of the various generations of Leaf modules around the forum or the web, along with their capabilities.



its a sensorless motor, and I expereinced with my small LIPOs I put in as a test that it did work better, less voltage sag and more power, so the battery was limiting here.
The sensorless controller probably isn't very good at low motor speeds, so changing the gearing will help with that, and if it's not changing to a better sensorless controller, especially one that is FOC, will work better. Something like the Phaserunner or similar, or perhaps a KT controller with opensource firmware OSFW loaded on it, (there's at least one thread about that), etc.



the motor and controller both got barely warm after my usual ride. maybe 45C. easy to touch, right after driving for 8km and up the hill on the end, guess that means that they are capable of more?
Yeah, 45C is not much--my DD hubmotors on the trike get hotter than that by quite a bit in the summer here.
 
The gear reduction is the #1 thing to do to improve the performance. As for batteries, in between the heavy, sluggish SLA batteries and the powerful but dangerous R/C batteries, there are several types of lithium batteries you can use to replace the SLA pack and get more performance, more range, and probably less weight as well. You can use LiFePo4 pouches for safety, or 18650 laptop batteries for performance. You should be able to find a pre-built pack of either of those in the correct size, dimensions, and voltage. Just eliminating the HUGE voltage sag of the SLA batteries will make it seem like a new, bigger motor.
 
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