About to purchase my first electric bike kit. Plan on going with a front hub kit from ampedbikes.com and 48v 20ah LiFePO4 from somewhere. I think it's a 500w motor. I was wondering if this is a decent choice for someone who's top priority is going far. Is there anything out there that would be significantly better?
Best set-up for range minded individuals
- Thread starter Rifle
- Start date
It depends on how much pedaling you're willing to do.
My set up (408 front hub, 20ah48v Lifepo4) I get 30-32 miles full throttle with minimal pedaling and as much as 60 miles going 15-17mph with moderate constant pedaling.
In general with a 400 series motor you should be able to do 50 miles or so with 1kwh of battery and mild hills/low wind.
Regards,
Bill
My set up (408 front hub, 20ah48v Lifepo4) I get 30-32 miles full throttle with minimal pedaling and as much as 60 miles going 15-17mph with moderate constant pedaling.
In general with a 400 series motor you should be able to do 50 miles or so with 1kwh of battery and mild hills/low wind.
Regards,
Bill
dogman dan
1 PW
In general, slower goes farther, so a motor who's efficient speed is slower will go far. The 408 is a good example. What is the top speed of it at 48v?
I get about 23 miles of full throttle riding out of my aotema (WE) motor on a ping 36v-20 ah battery. That is 23-24 mph on flat ground. My range test route is not flat, though, and has 500' vertical along the way, both up and down the hill. Slowing down extends range porportionally, so 25% less throttle gives about 25% more range, and so on. At 3/4 throttle, 15 mph or so, I can go about 28 miles.
The longest ranges are usuallly low wattage gearmotors that are used in a way that is more like a true assist, rather than a throttled motor. The bionx system in the lowest assist levels delivers phenomenal range. Others like bafangs, may have a 10 to 15 amp controller, so even at full throttle, they can only deliver half the wattage, so run time doubles. Coasting works great with gearmotors, and if the rider pedals a lot, some crazy long ranges can be done, especially on flat ground. I'm not sure that that kind of riding really qualifies as long range though, since the rider has to pedal so much.
I find three things kill range. Weight, combined with stops and starts. Weight, combined with uphill. And wind, whether from mother nature, or from riding faster, the apparent speed of the bike matters. So if you ride 20 mph into 25 mph wind, you get range that is like your riding 45 mph. Wind is my biggest problem since my bike is set up for a comfort bike, upright riding position.
I get about 23 miles of full throttle riding out of my aotema (WE) motor on a ping 36v-20 ah battery. That is 23-24 mph on flat ground. My range test route is not flat, though, and has 500' vertical along the way, both up and down the hill. Slowing down extends range porportionally, so 25% less throttle gives about 25% more range, and so on. At 3/4 throttle, 15 mph or so, I can go about 28 miles.
The longest ranges are usuallly low wattage gearmotors that are used in a way that is more like a true assist, rather than a throttled motor. The bionx system in the lowest assist levels delivers phenomenal range. Others like bafangs, may have a 10 to 15 amp controller, so even at full throttle, they can only deliver half the wattage, so run time doubles. Coasting works great with gearmotors, and if the rider pedals a lot, some crazy long ranges can be done, especially on flat ground. I'm not sure that that kind of riding really qualifies as long range though, since the rider has to pedal so much.
I find three things kill range. Weight, combined with stops and starts. Weight, combined with uphill. And wind, whether from mother nature, or from riding faster, the apparent speed of the bike matters. So if you ride 20 mph into 25 mph wind, you get range that is like your riding 45 mph. Wind is my biggest problem since my bike is set up for a comfort bike, upright riding position.
icecube57
10 MW
I agree with dogman. I probably suggest a bafang motor @ 48v 20A controller should be pretty safe or a higher 400 series clyte. A 408 is the best of both worlds. If you dont mind pedaling.. a lower speed higher torque like a 4012 will always be efficent at 15-20mph and will pull like a rabid pack mule but its tops speed is something you can pedal along with and if you can match the motors speed while pedaling then that reduces you consumption drastically. Try a 408/4012 dual wound from The Power Ride Store and pair it with a 48v 20A controller that would be saaaweeeet!
nathan_jones
100 mW
- Joined
- Mar 8, 2009
- Messages
- 44
Hello all,
An interested topic you’ve started here, I have a question for Dogmann and other knowledgable E-bikes. Does the voltage effect the efficiently in real world application, as 36v theoretically flows easier (correct me if Im wrong). Could you run through the configurations of different setups varying volts, amps, and wattage motors.
thanx
An interested topic you’ve started here, I have a question for Dogmann and other knowledgable E-bikes. Does the voltage effect the efficiently in real world application, as 36v theoretically flows easier (correct me if Im wrong). Could you run through the configurations of different setups varying volts, amps, and wattage motors.
thanx
ecowheelz
100 W
Rifle said:
Isn't the Amped kit a 36V kit? You'll probably want to make sure the controller is compatible with a 48V battery...
ecowheelz said:
It voids the warranty, but I haven't heard of anyone having any problems with it handling 48v. The warranty is only 3 months anyways.
If I could pedal I wouldn't be getting a e-bike. I'm the kind of person who loved conquering big hills on a bike (still hated wind though). This e-bike is just to allow me to bike despite health problems that have developed, so really I'm looking for long range w/ minimal pedaling required. Doesn't sound like there's a way to be much more efficient out there so I think I'm gonna go ahead and order an amped kit while they're still on special.
dnmun
1 PW
for 48V you may need to add a little more resistance to the power resistor inline to the voltage regulator, and you could try to change the LVC, but i doubt if that is needed since the battery packs have LVC already. so i suspect it is a simple transition, but to go above that you will likely have to replace the 63V main caps in the controller to 100V.
i am upgrading a 36V 9 FET infineon to run up around 80V. i am replacing the caps with some 100V1000uF caps i bot on ebay, and i think the 75V FETs will survive with the big caps to absorb the pounding on the FETs from the higher voltage, so the FETs don't breakdown. the sag when i am running current out of the pack should drop the voltage below 75V right away so the caps are the most critical to replace.
i will be selling/sharing the 100V1000uF caps at 30 cents each plus postage if you wanna go higher than 48V nominal.
i am upgrading a 36V 9 FET infineon to run up around 80V. i am replacing the caps with some 100V1000uF caps i bot on ebay, and i think the 75V FETs will survive with the big caps to absorb the pounding on the FETs from the higher voltage, so the FETs don't breakdown. the sag when i am running current out of the pack should drop the voltage below 75V right away so the caps are the most critical to replace.
i will be selling/sharing the 100V1000uF caps at 30 cents each plus postage if you wanna go higher than 48V nominal.
dogman dan
1 PW
Ask the vendor about the controller, 48v lifepo4 compatibility. With sla's it usually works since the battery hot off the charger will lose a few volts right away and be less likely to blow the caps. With lifepo4, you may do a lot of the ride with 58-60 volts so that is a bit close to the 63v caps theoretical upper limit. But your caps may stand more, or less, so it is a bit of a risk. They do the same thing with the aotema controllers, and usually get away with it , at least for awhile. Later, you could just get a 72v controller if you have to.
You should be able to, on flatter terrain, get a very minimum of 25 miles of range out of a 48v 20 ah battery, and maybe more depending on speed. Is that enough? If not, maybe two batteries, 15 ah, and carry in a set of panniers. The only way to extend range without more pedaling is to ride slow. At 12 mph, I can go 12 miles on a 24v 8 ah nicad pack. Theoretically, then, I could ride the same speed on a 48v 20 ah lifepo4 and go 60 miles.
You should be able to, on flatter terrain, get a very minimum of 25 miles of range out of a 48v 20 ah battery, and maybe more depending on speed. Is that enough? If not, maybe two batteries, 15 ah, and carry in a set of panniers. The only way to extend range without more pedaling is to ride slow. At 12 mph, I can go 12 miles on a 24v 8 ah nicad pack. Theoretically, then, I could ride the same speed on a 48v 20 ah lifepo4 and go 60 miles.
dogman dan
1 PW
Thanks, I wondered how that compares with my aotema so I could say which 400 series clyte it is similar to. I've been guessing a 407.
I just realizied we never really answered a question. Volts, and amps do affect efficiency, and those really interested should play with the simulator on the ebikes-ca website. But in the real world of how deep is your wallet, how do I carry this thing, how far do I need to go, other considerations far outweigh the impact of small efficiency differences. You do want to choose the right motor though, for the job you are doing. The closer you are to having a motor that runs at full throttle at the speed you want to go the better. Particularly you don't want too fast a winding, like a 405 if you will be going real slow up a hill all the time. Nor do you want a 4011 if you are going to ride 25 mph on flat terrain. The 407 or the 408 are good compromise sizes to do both. In general, the 4011 would start up better, while a 405 would lug a lot till it got going faster. So for stop and go, a real fast motor is not so great. The gearmotors have an advantage since the gearing lets them run at faster speeds which allows a smaller motor to have more power. They may or may not be more efficient, depending on how they are ridden. The rider is the real variable in efficiency in my opinon if the motor is not badly mismatched.
But back to the volts and amps, To go farthest, the biggest battery readily avaliable goes farthest. A 48v 20 ah simply has more battery weight than the 36v 20 ah from the same vendor. 48v will go faster, but to get the most range out of it, you have to ride slower than it's top speed. So if a 36v battery at full throttle is more efficient than a 48v battery at the same speed, the 48v still goes farther since it is simply bigger by 25% .
On the amps side, a higher amp controller will start faster, and use more power then than a lower amp controller. So the most efficient setup for flat gound would be a low amp controller. Kinda like a brick under the cars gas pedal will improve mileage since you can't floor it anymore. For hills, though, you may need the higher amps to get up the dang hill without lugging the motor down to too slow a speed where it runs with horrible efficiency. Again, this is where the gearmotors have an advantage, they can still climb a hill with a lower amp flow, though slower. The gearmotors are just harder to lug down.
On the other hand, in my opinion the easiest battery to find a box or bag to carry it in is the 36v 20 ah since it is a perfect size for many rack boxes and bags, and weighs only 15-16 pounds. The 48v 20 ah is a bit heavy for a seatpost rack, and can be top heavy if carried high enough.
15mph seems to be the speed of choice for those who need extreme range. It's slow, but not slower than pedaling an ordinary bike by too much. 20 mph is a good compromise, and some motors, that is top speed at 36v. Above 20 mph, wind gets much more costly in range. Wind resistance is exponential, so the cost of every mph more is more than you think.
I just realizied we never really answered a question. Volts, and amps do affect efficiency, and those really interested should play with the simulator on the ebikes-ca website. But in the real world of how deep is your wallet, how do I carry this thing, how far do I need to go, other considerations far outweigh the impact of small efficiency differences. You do want to choose the right motor though, for the job you are doing. The closer you are to having a motor that runs at full throttle at the speed you want to go the better. Particularly you don't want too fast a winding, like a 405 if you will be going real slow up a hill all the time. Nor do you want a 4011 if you are going to ride 25 mph on flat terrain. The 407 or the 408 are good compromise sizes to do both. In general, the 4011 would start up better, while a 405 would lug a lot till it got going faster. So for stop and go, a real fast motor is not so great. The gearmotors have an advantage since the gearing lets them run at faster speeds which allows a smaller motor to have more power. They may or may not be more efficient, depending on how they are ridden. The rider is the real variable in efficiency in my opinon if the motor is not badly mismatched.
But back to the volts and amps, To go farthest, the biggest battery readily avaliable goes farthest. A 48v 20 ah simply has more battery weight than the 36v 20 ah from the same vendor. 48v will go faster, but to get the most range out of it, you have to ride slower than it's top speed. So if a 36v battery at full throttle is more efficient than a 48v battery at the same speed, the 48v still goes farther since it is simply bigger by 25% .
On the amps side, a higher amp controller will start faster, and use more power then than a lower amp controller. So the most efficient setup for flat gound would be a low amp controller. Kinda like a brick under the cars gas pedal will improve mileage since you can't floor it anymore. For hills, though, you may need the higher amps to get up the dang hill without lugging the motor down to too slow a speed where it runs with horrible efficiency. Again, this is where the gearmotors have an advantage, they can still climb a hill with a lower amp flow, though slower. The gearmotors are just harder to lug down.
On the other hand, in my opinion the easiest battery to find a box or bag to carry it in is the 36v 20 ah since it is a perfect size for many rack boxes and bags, and weighs only 15-16 pounds. The 48v 20 ah is a bit heavy for a seatpost rack, and can be top heavy if carried high enough.
15mph seems to be the speed of choice for those who need extreme range. It's slow, but not slower than pedaling an ordinary bike by too much. 20 mph is a good compromise, and some motors, that is top speed at 36v. Above 20 mph, wind gets much more costly in range. Wind resistance is exponential, so the cost of every mph more is more than you think.
davespicer
100 W
For me, the discussions of practicality here on ES go beyond "informative" - they're downright comforting. Most people know someone who has lots of off-the-wall ideas but very little common sense. (For those who don't, there are my posts on motor cooling...) Thus I can tie myself in knots trying to figure out some odd way of doing something. At the high end of mechanical skill and budget, this creativity can produce spectacular results, as with the multikilowatt projects and the steel-bending ultracapacitors on this forum. But farther down the scale of skill and shekels, it ain't pretty.dogman said:
The last couple of days I got intrigued with the idea of adding 6 volts to two of our electrics - the Wal-Mart eZip and the BL36 Ross. Figured the MY1018 would hold together better under 30 volts than 36, and the BL36 would do a bit better speedwise with 42 volts without all the expense of going to 48. Fine, but that still leaves them both with SLAs, and the 6v pack has to be lashed on and wired in but charged separately, and... and...
So it sounded nice on paper but just wasn't practical.Following the accounts of what actually works shows me (and many others, I'd bet) a path that leads somewhere and a means of getting there. So thanks everyone
dnmun
1 PW
what's this real world nonsense?
we are all just a collection of little magnetic blips on a hard disk in one of those ATX cases knightmb has stacked on the steel shelves behind his desk.
you can run the voltage on the motors as high as you wish, as long as it doesn't breakdown the insulation on the windings to ground.
the controllers are made from electronic components which operate in different voltage regimes, and the size of the power drop to the input of the voltage regulator inside the controller has to be adjusted, along with the LVC. but to run at different voltages, you can just change out some of the electronic components in the controller for higher voltage spec parts.
steps up from 50V, 63V, 80,100,150 for caps and similar for FETs. the controller built for 36V will run at 48 and 72 usually, but still should be modified to perform more reliably.
i got my 36V infineon controller to run all the way up to 90.6V yesterday, but had to quit because it starts cutting out. but 80V was easy. but hard on the voltage regulator, which is why the 90V was cutting out, i think.
but that was freewheeeling with no load, i am gonna add the 100V1000uF caps before i put a heavy load on it for hours.
also i will adjust the power resistor up to about 660R from the current 330R so that the voltage input to the regulator stays around 40, which means it is 28V across the regulator above the 12V buss output, well in range for the voltage regulator spec.
we are all just a collection of little magnetic blips on a hard disk in one of those ATX cases knightmb has stacked on the steel shelves behind his desk.
you can run the voltage on the motors as high as you wish, as long as it doesn't breakdown the insulation on the windings to ground.
the controllers are made from electronic components which operate in different voltage regimes, and the size of the power drop to the input of the voltage regulator inside the controller has to be adjusted, along with the LVC. but to run at different voltages, you can just change out some of the electronic components in the controller for higher voltage spec parts.
steps up from 50V, 63V, 80,100,150 for caps and similar for FETs. the controller built for 36V will run at 48 and 72 usually, but still should be modified to perform more reliably.
i got my 36V infineon controller to run all the way up to 90.6V yesterday, but had to quit because it starts cutting out. but 80V was easy. but hard on the voltage regulator, which is why the 90V was cutting out, i think.
but that was freewheeeling with no load, i am gonna add the 100V1000uF caps before i put a heavy load on it for hours.
also i will adjust the power resistor up to about 660R from the current 330R so that the voltage input to the regulator stays around 40, which means it is 28V across the regulator above the 12V buss output, well in range for the voltage regulator spec.
dogman dan
1 PW
Huh? I still need a translator for some smarter peoples comments. Must be nice to really understand this stuff. I start to get a clue the second time smoke comes out of something. Hmm, could it be something I''m doing? Must be, it happend twice! :lol:
dnmun
1 PW
its not that bad, i didn't have a clue until richard sent me to read that document from QD-TEK.uk about the design of PWM controllers. and reading the threads that knuckles put together on the infineon, and dr bass had great pictures on the 18 FET thread so you can see the individual surface mount parts, and then jeremy and wayne figured out the circuits so it was just a long disparate collection of threads. phil has a number of little thingys and geoff clued me in on my controller initially. now wayne has pretty well explained what the sensorless circuits are doing too. this is a great place for it if you are interested.
i am now a great believer in the value of big capacitors. i wonder if the problem that bioman is having will be solved by adding caps, and if so then that could help a lot of people with the GM regen controllers.
looking ahead, i think a lot of people are gonna go right on up to 72V lithium, the BMS is available, the vendors even sell 72V BMS packs, more speed, cooler controller, bigger smile. more bugs in your teeth. close to in town traffic speeds.
i am now a great believer in the value of big capacitors. i wonder if the problem that bioman is having will be solved by adding caps, and if so then that could help a lot of people with the GM regen controllers.
looking ahead, i think a lot of people are gonna go right on up to 72V lithium, the BMS is available, the vendors even sell 72V BMS packs, more speed, cooler controller, bigger smile. more bugs in your teeth. close to in town traffic speeds.
Russell
1 MW
I'm not picking on you Dogman but these items you spoke about seem to be general misconceptions;
The controller amp limit is just that a limit, it does not mean the motor will be drawing that current continuously so a motor with a 15A controller does NOT get double the range of that same motor using a 30A controller. In practice the peak currents will be higher during acceleration and hill climbing with the higher current controller but the current at cruise speeds and anytime less than 15 amps are required will be the same between the two controllers at the same speed. For example at WOT on the flats my Bafang will do low 17 mph and draw about 5.5A which would be the same with either a 15A or 30A controller. Range will be greater with the 15A but not by a huge margin though it depends greatly on the grades encountered and how aggressively the rider uses the throttle.
The power consumed when riding 45mph in calm conditions and riding at 20mph with a 25mph headwind are NOT the same. A rider has to input sufficient power to overcome three forces as he moves along; losses due to mechanical friction, rolling resistance and aerodynamic drag. Friction is fairly constant and is typically around a few to 5%. Rolling resistance is fairly linear with respect to speed while aero drag is exponential with respect to speed. So if you are riding at 20mph with a 25mph headwind you have frictional losses, rr losses from traveling at 20mph and the same aero drag as at 45mph so total energy required is NOT the same as at 45mph since at that speed you have the rr losses from traveling at 45mph. A cycling power calculator can be used to find that the power required to travel at 20mph into a 25mph wind is roughly equivalent to riding at 34mph in calm conditions.
-R
dogman said:
The controller amp limit is just that a limit, it does not mean the motor will be drawing that current continuously so a motor with a 15A controller does NOT get double the range of that same motor using a 30A controller. In practice the peak currents will be higher during acceleration and hill climbing with the higher current controller but the current at cruise speeds and anytime less than 15 amps are required will be the same between the two controllers at the same speed. For example at WOT on the flats my Bafang will do low 17 mph and draw about 5.5A which would be the same with either a 15A or 30A controller. Range will be greater with the 15A but not by a huge margin though it depends greatly on the grades encountered and how aggressively the rider uses the throttle.
dogman said:
The power consumed when riding 45mph in calm conditions and riding at 20mph with a 25mph headwind are NOT the same. A rider has to input sufficient power to overcome three forces as he moves along; losses due to mechanical friction, rolling resistance and aerodynamic drag. Friction is fairly constant and is typically around a few to 5%. Rolling resistance is fairly linear with respect to speed while aero drag is exponential with respect to speed. So if you are riding at 20mph with a 25mph headwind you have frictional losses, rr losses from traveling at 20mph and the same aero drag as at 45mph so total energy required is NOT the same as at 45mph since at that speed you have the rr losses from traveling at 45mph. A cycling power calculator can be used to find that the power required to travel at 20mph into a 25mph wind is roughly equivalent to riding at 34mph in calm conditions.
-R
davespicer
100 W
Um, okay, but instantaneous power requirements aren't the same as amp-hours used. If you ride slower into a headwind it's gonna take you longer to get there.Russell said:
Russell
1 MW
davespicer said:
I don't know what your statement has to do with what I wrote but yes of course unless you have unlimited power on tap that's exactly what you'll do when faced with a strong headwind, slow down.
-R
dogman dan
1 PW
Ok I'm always willing to learn more. I often oversimplify, since many go the opposite way, and for the new folks it's pretty confusing.
So I'll buy what you are saying and just say, a bafang is reported to go 17 mph drawing 5.5 amps, (don't know what voltage) while the aotema I ride draws closer to 10 amps at a similar speed on a 36v pingbattery. Still looks to me like the bafang draws less amps for whatever reason. Safe guess that the bafang goes farther than the aotema on the same battery.
On the wind thing, I'm sure you are also correct, there is a lot more to drag than just the wind. A lot of newbs have no idea that riding fast costs so much, so they don't get it why 12 mph is so very much more efficient than 25. They do lots of range calculations like wind will never affect thier ride too. I may have it sorta wrong how much, but I definitely stand by saying that wind kills your range if it is in your face.
So I'll buy what you are saying and just say, a bafang is reported to go 17 mph drawing 5.5 amps, (don't know what voltage) while the aotema I ride draws closer to 10 amps at a similar speed on a 36v pingbattery. Still looks to me like the bafang draws less amps for whatever reason. Safe guess that the bafang goes farther than the aotema on the same battery.
On the wind thing, I'm sure you are also correct, there is a lot more to drag than just the wind. A lot of newbs have no idea that riding fast costs so much, so they don't get it why 12 mph is so very much more efficient than 25. They do lots of range calculations like wind will never affect thier ride too. I may have it sorta wrong how much, but I definitely stand by saying that wind kills your range if it is in your face.
Russell
1 MW
dogman said:
Direct drive motors are supposed to be a tad more efficient than geared though I think that's only true if a person is always on the throttle. I think the ability of the geared motor to freewheel more than makes up for the slightly lower motor efficiency. In any event if your motor is truly drawing 10A at 17mph then it's likely due to an overall comparatively inefficient bike. My bike is a hybrid which I rode for many miles before I converted it so it does roll quite efficiently down the road.
Any cyclist knows just how brutal the wind can be however you’re right I think a lot of folks who are looking at ebikes may not ride a regular bike much. It’s actually quite amazing how much energy it takes to overcome even a small headwind or slight grade when you’re cycling even at normal recreational speeds. Previous to this year I only rode regular bikes but now with the WU meter in front of me I can literally see in numbers why certain stretches of road or wind conditions caused me so much pain as I tried to maintain a constant speed. With an ebike, and especially a powerful one, those things become less of a problem but they still of course greatly influence energy use and range. It’s the same thing with a car where power is by comparison unlimited and aerodynamic drag, weight and all that kind of stuff seems irrelevant. The thing is if every car had an instantaneous mpg readout directly in front of the driver maybe the people driving 3-ton SUV’s down the freeway at 80 mph would slow down. Heck asking Americans to slow down to save fuel---unthinkable! But I digress.
-R
JinbaIttai
100 W
The ampedbikes controller will handle 48V lifepo4 no problem out of the box.
That motor is one of the most efficient ones you can buy. But one problem is where that ideal spot for efficiency lies. For the ampedbikes motor it is above 20 mph at 36V, and above 25 mph at 48V, according to the simulator. Those are not ideal sweet spots to go the longest distances because up there is more wind resistance and it is usually a little beyond the comfortable range of the gearing of a typical bicycle.
Getting the wind resistance sweet spot to match the bike's gearing sweet spot to match the motor's RPM sweet spot is the trick.
I suggest going for it anyways. E-bikes aren't exactly the perfect hypermiling machines just yet. Maybe in a few more years.
That motor is one of the most efficient ones you can buy. But one problem is where that ideal spot for efficiency lies. For the ampedbikes motor it is above 20 mph at 36V, and above 25 mph at 48V, according to the simulator. Those are not ideal sweet spots to go the longest distances because up there is more wind resistance and it is usually a little beyond the comfortable range of the gearing of a typical bicycle.
Getting the wind resistance sweet spot to match the bike's gearing sweet spot to match the motor's RPM sweet spot is the trick.
I suggest going for it anyways. E-bikes aren't exactly the perfect hypermiling machines just yet. Maybe in a few more years.
Russell
1 MW
JinbaIttai said:
You might want to try something other than 100% throttle when you look at a motor with the ebikes.ca simulator. For example with the throttle at 80% the "sweet spot" is down around 18mph (2807/36V/26") and the efficiency only drops about 1%. It would be silly to ride at full throttle and 22mph just in the name of efficiency because the actual range would be much further at 18mph Vs 22mph due to the lower power required.
-R
JinbaIttai
100 W
Russell said:
You can change the throttle on the simulator? That changes everything then.
dogman dan
1 PW
Yeah, I kinda had that misconception for awhile too. I thought since the motor seemed to run better at full speed it would be more efficient to run full throttle. Especially on uphills. It IS true that stalling the motor makes heat instead of motion, but at the risk of oversimplifying again, in general, slower saves a lot more energy due to less wind than the loss of motor efficiency could ever equal. So even if you lose some efficiency at a lesser throttle setting, the wind resistance is so much less the motor efficiency is meaninless.
When climbing hills though, I don't know, my gut feeling is that there is no getting away from the basic law of physics that lifting weight takes a certain minimum work, no matter what speed, so while you might save some wind resistance by slowing down, the hill remains and nothing can make that take less energy.
When climbing hills though, I don't know, my gut feeling is that there is no getting away from the basic law of physics that lifting weight takes a certain minimum work, no matter what speed, so while you might save some wind resistance by slowing down, the hill remains and nothing can make that take less energy.
nathan_jones
100 mW
- Joined
- Mar 8, 2009
- Messages
- 44
thanks dogman for explaining the amps, volts etc. very understandable. you comment of havin a motor speed at full throttle closer to your desired top speed makes sense.
however i have another question. (prepare yourself it might be a bit stupid)
if the same wattage battery eg 24v20amph and a 48v10amph which would get you futher (be more efcient) with moters geared gor the same top speeds as before mentioned voltages. and what are the reasons why?
ps i totaly agree with davespicer it is great to have so many willing to share their knowledge here
however i have another question. (prepare yourself it might be a bit stupid)
if the same wattage battery eg 24v20amph and a 48v10amph which would get you futher (be more efcient) with moters geared gor the same top speeds as before mentioned voltages. and what are the reasons why?
ps i totaly agree with davespicer it is great to have so many willing to share their knowledge here
