Dave
Does more controller, motor current not = more watts, hence more power and more speed?
If the above is not true I'd appreciate a quick explanation, if there is one.
Many thanks
Legality of having a switch to meet 250w regulations
- Thread starter Geebee
- Start date
Does more controller, motor current not = more watts, hence more power and more speed?
If the above is not true I'd appreciate a quick explanation, if there is one.
Many thanks
I'll try again.
What is being talked about in this thread? Is it a Electric Assisted Pedal Cycle or EAPC in which case it must match in performance anything that an ordinary cyclist can achieve on one but never ever exceed it. The continuous maximum rating is important but nowhere near as important as the maximum peak rating which under UK Law has been set at 650 Watts or three quarters of a Horse Power.
If you aren't talking about EAPC's the you must be talking about a new class of vehicle that the Ministry of Transport has not yet defined. I will tell you what the European maximum peak rating is if it differs from the UK one when I get an answer from my MEP.
Yours sincerely
Linfitter
)geebee talked about e-bikes (EAPC), arbol talked about 1kw e-bike, which (although speed restricted) can be registered as e-moped (SEL) in Spain.
Hang on, does any one have a motor test report for the 8-Fun 48V 22Amp 270 RPM?
It depends on the gradient. If you give me the gradient, I'll try to calculate the climbing speed for each motor.
Hang on, does any one have a motor test report for the 8-Fun 48V 22Amp 270 RPM?
D
Deleted member 4366
Guest
More amps gives more speed capability, but as the motor speeds up, it generates a back EMF, which opposes your battery voltage, so current goes down until it's zero at the motors own top speed of rotation. That's why it's important tp know the motor's rpm from its specification. Current helps hill-climbing provided that the motor doesn't become saturated, but can't make it spin faster. You need higher voltage for that.
Some motors can only take a certain amount of current. Turning the controller up doesn't push more current in. the voltage pushes the current through the motor, and it can only push so hard.
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D
Deleted member 4366
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The requirements of EN15194, which is the European standard that sort of applies in the UK.
D
Deleted member 4366
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I'd like to add that although one can guess that running at 48V instead of 36V is going to deliver more Watts, the RPM at the sweet zone of the motor moves up with the voltage. Outside the sweet zone, the (maximum) power output depends so much on the motor efficiency at the RPM you are interested in. How effective a motor is against one particular hill can be guessed at but not against any hill.
Unless in the real world the motor isn't reaching full speed due to not having enough power to reach its max RPM (more an issue at higher speeds), same applies as inclines increase, a higher amp controller will allow the motor to hold a higher speed under load.
I take it that we are talking about maximum achievable speed with a motor on a particular gradient?
I find that the easiest way to figure out how your projected motor is going to perform is using the ebike simulator here:
http://www.ebikes.ca/tools/simulator.html
I am making a simpler excel formula, I can post it here if anyone is interested.
I find that the easiest way to figure out how your projected motor is going to perform is using the ebike simulator here:
http://www.ebikes.ca/tools/simulator.html
I am making a simpler excel formula, I can post it here if anyone is interested.
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D
Deleted member 4366
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They have. It's the fifth one down, which I think is a code 10.
The BPM is the same as the BMC V2 as well, so you can use the "torque" version for the code 13 BPM and the "speed" version for the Code 8. The 201 BPM is code 15. You have to extrapolate to get an idea of what it can do.
The BPM is the same as the BMC V2 as well, so you can use the "torque" version for the code 13 BPM and the "speed" version for the Code 8. The 201 BPM is code 15. You have to extrapolate to get an idea of what it can do.
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Wow, a 201rpm BPM (code 15) at 48V must be a monster, and probably the best if one wants to keep speed below 25km/h but having strong acceleration capabilities.
In your opinion, d8veh, is a 201rpm BPM at 48V (say with a S12P @ 30A) "too much"? Or maybe a 36V with also high amperage, which would give a lower max speed, and as a consequence, more efficiency at low speeds?
In your opinion, d8veh, is a 201rpm BPM at 48V (say with a S12P @ 30A) "too much"? Or maybe a 36V with also high amperage, which would give a lower max speed, and as a consequence, more efficiency at low speeds?
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d8veh, I believe the BPM36V is a code 11, since I get for 700c wheel (for speed loads, which is the max speed assuming pedalling adds very little):
32.5km/h for Torque (code 13)
41.1km/h for Speed (code 8)
and 35.9km/h for BPM36V
If I take a linear relation between the two extremes, I get 1.72km/h per code. Then, subtracting 2 codes to the code 13, I get 32.5+2*1.72 = 35.94km/h, which is very close to the 35.9km/h I get from the simulator.
A code 15 would have then a 29km/h load speed.
As a consequence, a BPM36V code 15 (201rpm) with a powerful 36V battery would be quite well suited for a max speed of 25km/h (a limitation with the LCD to max speed of 25km/h would detract very little performance).
Does it make sense?
32.5km/h for Torque (code 13)
41.1km/h for Speed (code 8)
and 35.9km/h for BPM36V
If I take a linear relation between the two extremes, I get 1.72km/h per code. Then, subtracting 2 codes to the code 13, I get 32.5+2*1.72 = 35.94km/h, which is very close to the 35.9km/h I get from the simulator.
A code 15 would have then a 29km/h load speed.
As a consequence, a BPM36V code 15 (201rpm) with a powerful 36V battery would be quite well suited for a max speed of 25km/h (a limitation with the LCD to max speed of 25km/h would detract very little performance).
Does it make sense?
D
Deleted member 4366
Guest
You have to try a few to know the answer. To me, there's a happy maximum power and torque, after which your ride is no longer relaxing. If you want an electric assisted bicycle, and you weigh about 80 kg. A 270 rpm 36v Bafang CST at 25 amps will give you everything you want. If you're 100kg or want to tow a trailer, a 250 rpm one at 30 amps would be nice. The problem is to find the motor with the correct RPM. You only need 48v if the motor is too slow. A 201 rpm motor, say code 15 BPM, becomes a 270 rpm one at 48v, but then you don't need so much current for the same power, so 25 amps for a heavyweight or 22 amps for a normal guy should be about right.
if you want a 25 to 30 mph electric moped, the 1000w direct drive motors become more suitable.
If you only want 25 km/h, a 36v code 15 BPM at 36v will be perfect. Choose the current according to your weight.
if you want a 25 to 30 mph electric moped, the 1000w direct drive motors become more suitable.
If you only want 25 km/h, a 36v code 15 BPM at 36v will be perfect. Choose the current according to your weight.
Why is that? A BBS-01 weights about 4kg, which is more than the 2kg of a say q100.
But it is true the BBS-01 has the weight better centered, which would be a good thing for a light bike, such as a singlespeed.
Would it make any sense to have a BBS-01 with a singlespeed?
D
Deleted member 4366
Guest
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