High power controller and battery
- Thread starter Andy1865
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AHicks
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- USA
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- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Based on my experience with a little smaller 1500w DD system, your battery sounds like it's going to be a little light in the butt if you're plans are to go very far with it.
My batt. is 48v 14.5 amp, and 20 miles of coastal riding (lots of rolling hills) will have it down to 48v or so. I have max available wattage set to about 1100. If I were doing it again, I'd be looking at something closer to 20a.
My batt. is 48v 14.5 amp, and 20 miles of coastal riding (lots of rolling hills) will have it down to 48v or so. I have max available wattage set to about 1100. If I were doing it again, I'd be looking at something closer to 20a.
AHicks
Well-Known Member
- Region
- USA
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- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
What are your plans for this bike? Why the 2000w power? Is this a direct drive or a gear drive? Hub mount or mid?
I'm asking as generally people would buy 2000w of power for fairly high performance. Issue here being running that on a 15 amp battery. The battery will be OK, assuming it's wired heavily enough to have 2000w (35a) pulled from it, but with that kind of draw, your range is not going to be good. Yes, you can probably get 15 miles out of it, but you're going to have to be pretty conservative supplying a lot of power yourself.
I'm asking as generally people would buy 2000w of power for fairly high performance. Issue here being running that on a 15 amp battery. The battery will be OK, assuming it's wired heavily enough to have 2000w (35a) pulled from it, but with that kind of draw, your range is not going to be good. Yes, you can probably get 15 miles out of it, but you're going to have to be pretty conservative supplying a lot of power yourself.
Andy1865
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- United Kingdom
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- Skipton
Just a new ebike as my Freego 250w is mainly for road which i'll prob sell now. The new ebike is Direct Drive and rear hub mounted. Just wanted something with abit of power to get me up the homeward bound hill instead of getting off and pushing half way. The company that im buying from is called Hi-powercycles UK also known as Xipi i think
AHicks
Well-Known Member
- Region
- USA
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- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
I think that maybe that battery is being advertised at the voltage the charger will shut down at, making it a 48v battery for comparison purposes.
Also, though the motor may be capable of 2000w, to my knowledge few are actually rated according to controller amp capacities. That may be a mistake on my part though. Something new or a lack of understanding on my part.
Also, though the motor may be capable of 2000w, to my knowledge few are actually rated according to controller amp capacities. That may be a mistake on my part though. Something new or a lack of understanding on my part.
I'm working on project ebikes in that same power range 52-60V nominal / 30-40A. If you visit ebikes.ca (Grin Technology) you can actually run simulations that project the performance you can expect with various motors they have modeled. You'll probably have a good high cruising speed in the 32-36mph range (that is on flat surfaces requiring from 1300-1600 watts). Direct drive motors are actually very efficient at these speeds and hardly the over-powering motors that some like to imply they are. Most likely you'll want to ride the bike with your pedaling input in the 25-30mph range to get good range and commute speeds as the power required is much less.
One of the things no one in this industry likes to talk about is how ineffective and mechanically inefficient mid drives become when riding at speeds above say 25mph (when you use a front chain ring in the range of 44T and on a rear in the 11-13T range the mechanical losses are significant with only about 25% of the motor torque being transmitted to the rear wheel). DD and geared hub motors do have a disadvantage at the lower speed when gearing can help mid drives but human power is more effective at lower speeds so in my opinion the best solution for commuting ebikes is going with a rear direct drive or geared hub motor.
You will want as much battery capacity as you can get on a fast ebike regardless - 1000wh or more in my opinion.
AHicks
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- USA
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- Snow Bird - Summer S.E. Michigan, Winter Gulf Coast North Central Fl.
Regarding "trickle charger". Generally, trickle chargers don't shut off. They maintain a small amount of electricity to the battery to keep it topped off. On Lithium based batteries, trickle chargers are a major no-no. The charger used for a Lithium battery must be designed to bring the voltage up to a certain point, then shut off completely.
If a good quality motor probably in the range of 80-100Nm but keep in mind that rolls off with increasing RPMs and the rate of the reduction is based on the winding / KV of the motor. You need around 30Nm at the rear wheel to sustain 35mph (depending on multiple factors of coarse).
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