there are many 3500watt,,4500watt ,6000watt even higher power scooters, from our China side opinion, those are motor maxmium power, however, for the certain battery supply reason, the scooter can not work in the maximum power for half an hour , even less. however, some users regards it is the same with gasoline scooter, becuase only if there is gasoline, the gasolin scooter can get that horse power.
the motor power is like a receiving water(current) tank , can the battery supply so big water (current) to input this tank? don't misunderstand the motor power is scooter working power.
however, for the electric scooter, the power is from the battery, the battery can not last for one hour or two hours under high current , in case at high current discharge, how many minutes will the battery last? how long the range ? what temperature of the motor and controller ? once the battery is start to work, the voltage will get low, when the battery get lower and lower, the speed will be low. so I recommend the user pay attentaion to the following parameters of the e scooter:
1 torque and its speed under this torque
2 climbility
3 load capacity
4 work efficiency point and its efficiency range ...
5 range
I am sorry I am not a professionor but I would like to discuss with visitors for something here .
in fact, after full recharing the 4X 12v battery , the voltage can be 52V, if you let the work current is 80A( the controller can set the value) so the power watt can be 4kw ( under the motor is 4kw) this MAXmium power is 4 kw, this is the peak power. if the battery is 40ah ,50ah, how long it can last? the hours is 50ah/80a=0.625hrs. provided the scooter can work at 80A for 0.625hours, the range is topspeed X 0.625= ?km, athough this is a simple calculation ....
in fact, the motor speed( scooter speed) = N ( rpm) x 60 x tyre cycle length(mm)/1000,000= ? kmph
rpm=round per minute, N
( 1hour=60minutes)
tyre cycle length(mm)
(1km=100,000mm)
so the top speed is not subject to the motor power.
just see the power watt of scooter will give you misunderstanding . judging a scooter good or not is not from its power, but the above 5 items I wrote.
Power at speed on most scooter setups is actually limited by motor back-emf.
on my scooter for example, battery side amps is limited to 120A (voltage sags to 50v, giving 6kw)
however, when at top speed, the most the controller can draw is 40-50A.
there are to many concepts to cover to properly answer your original question, however, to give you a better understanding ill give you this graph, showing max available power and load at different speeds:
the power shown is power drawn by the controller at full throttle, not power at the wheel.
The curve for power at the wheel will look very similar, however the flat line in the curve will have more of a rise to it as the motor efficiency is variable.
range is determined by how much power is required to maintain a specific speed.
Matt
Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km
what meaning above is : checking the scooter power good or not is not from the maxmium power, so please see the motor curve below.
www.topmotorx.com
Dear "little":
I didn't see any question in your post, only a very sensible and justified summary of EV power perceptions:
But you then seem to ask a qurstion:
The answer to the "how long can it last" question depends on the result of Peukert's equation. The AH rating of a battery is generally determined at a 20 hour rate, the rate needed to use all capacity in 20 hours. At higher rates, the actual capacity is MUCH less. PowerSonic has some typical charts of how heavily Peukert hurts us when we're going full throttle. A good one is on page 5 of the PDF:
http://www.power-sonic.com/index.php?doc_id=34
You are proposing discharging your battery at 1.6C, which will only let you get a fairly small fraction of the the battery's energy out.
The other side of this is that if you can keep your amp draw low, you can get MORE energy out. In effect, your "gas tank" is larger when you are going slower.
Is that an answer to your question?
Hello Mf70, becuase there are many users like high power (3kw, 4kw, or 6kw) scooter, but they don't consider the battery supply , they think the more higher power motor , the better scooter is. so I have no question to ask, I just remind of most users not mislead by the only one factor -----so called higher power, 3kw, 4kw, or ....6kw....
www.topmotorx.com