Using Your Throttle to Extend Range

6zfshdb

Well-Known Member
I've been working on an interesting experiment this season comparing PAS assist with a throttle cruise control device. I discovered using cruise control improves my battery range by an average of just over 14% under controlled conditions.

I made a series of 10 rides in the +/-40 mile range on a smooth, level, packed gravel surface. I used the same 48v 15ah battery, charged to 100%, with the bike weighted exactly the same. The tire pressure was set at 45 psi before each ride. All rides were done in the morning with the temperature between 65 and 75 degrees. I compensated for wind by riding in two directions.

5 of the rides were done using PAS 2 while maintaining 12 mph (the motor cutout speed). On the other 5 rides, I used the cruise control & throttle with the speed set to 12 mph. For all 10 rides, I used a consistent, moderate but comfortable cadence and amount of pedal pressure.

I used an ammeter & volt meter which reads to a hundredth of a volt. I rode until the battery depleted to exactly 20% of capacity and noted the mileage for each ride. The PAS rides averaged 42 miles and the throttle rides 48 miles for a net gain of 6 miles.

I realize it is difficult to judge the amount of muscle energy contributed to each ride but I made a conscious effort to maintain constant pedal pressure & cadence with the same number of no pedal rest periods. I believe the difference is due to improved efficiency by maintaining a constant speed as is the case with automotive cruise control.

On the PAS rides, I noted the motor current would surge occasionally when the motor worked harder to get back to the 12 mph PAS 2 cutout speed. This would occur after a brief rest period with no pedaling or variations in pedal pressure. The throttle, on the other hand, would maintain constant motor current during these brief variations with no surging.

Obviously, these results will vary with different bikes, riders, terrain and style of riding. In my case, a 6 mile per battery increase isn't all that significant but I thought it worth noting.
 

harryS

Well-Known Member
Not shabby at all is your 14% difference.

At that same average speed, 11-12 mph, this 195 lb rider burns 30-40% more AH than his 140 lb wife (similar size bikes, with same motor.) I also pedal harder, get far ahead, and coast while waiting for her to catch up. I always attributed the delta to the weight, but your findings suggest it's the weight magnified by her cruise control like riding.

None the less. I would go nuts trying to go 40 miles w/o pedaling, and to do that 5 times? Better you than me. Thanks for your contribution to ebike science!
 

6zfshdb

Well-Known Member
Not shabby at all is your 14% difference.

At that same average speed, 11-12 mph, this 195 lb rider burns 30-40% more AH than his 140 lb wife (similar size bikes, with same motor.) I also pedal harder, get far ahead, and coast while waiting for her to catch up. I always attributed the delta to the weight, but your findings suggest it's the weight magnified by her cruise control like riding.

None the less. I would go nuts trying to go 40 miles w/o pedaling, and to do that 5 times? Better you than me. Thanks for your contribution to ebike science!

I guess I didn't explain the process properly. I was pedaling and contributing about the same assist that I do on a normal ride. Although I've never tried it, I estimate I would get only 25 - 30 miles on battery alone.
 

6zfshdb

Well-Known Member
you have cruise control?

This device:

51I4sL7ZwUL._AC_SL1000_.jpg

It isn't true cruise control since it doesn't compensate for changes in slope, wind, riding surface etc. It works well on most rail trails though.
 

Handlebars

Well-Known Member
This device:

View attachment 61626

It isn't true cruise control since it doesn't compensate for changes in slope, wind, riding surface etc. It works well on most rail trails though.
Do you think it will fit most ebikes that have a lever throttle?
 

Handlebars

Well-Known Member
I guess I didn't explain the process properly. I was pedaling and contributing about the same assist that I do on a normal ride. Although I've never tried it, I estimate I would get only 25 - 30 miles on battery alone.
I guess I was wanting it to be that without pedalling you got better mileage :)
Another good comparison would be throttle only vs "control assisted throttle only".
In any case, I want the control helper because If I am loaded down with duffle bags I can't really pedal very well, so I use throttle only at times, but it gets very tiresome to hold the throttle in position and I don't want to develop any medical symptoms from it.
 

Bruce Arnold

Well-Known Member
Thanks for the data. Not a bad field test at all.

The cruise control on Juiced Bikes may be a little different. They have a feature called Throttle Assist Boost (TAB.) If you use the throttle while pedaling, you get more assist than from pedal assist or throttle-alone. It's like putting the bike into the highest level of pedal assist temporarily, which is R mode on newer Juiced bikes, S on the older ones. The motor doesn't know the difference between pedaling while using the throttle, or pedaling while using cruise control -- it's all TAB either way. Tora explained it in a video, that cruise control is the same as using the throttle as far as the controller is concerned.

That being the case, this test couldn't be done as you describe, because as soon as you start pedaling, you're in TAB, using way more current. The test would have to be pedal assist at a given level (2, in your test) while maintaining a steady speed, and cruise control without pedaling, at the same speed.

Who knows, I might give it a try. I've got an easy, mostly level 6 mile loop in my neighborhood. Since it's a loop, you'd be in the breeze from every possible direction. Run it several times in pedal assist and again on cruise control without pedaling and see what the results look like. Control for battery state of charge, tire pressure, ambient temperature, just like you did. Could be fun.
 

6zfshdb

Well-Known Member
Thanks for the data. Not a bad field test at all.

The cruise control on Juiced Bikes may be a little different. They have a feature called Throttle Assist Boost (TAB.) If you use the throttle while pedaling, you get more assist than from pedal assist or throttle-alone. It's like putting the bike into the highest level of pedal assist temporarily, which is R mode on newer Juiced bikes, S on the older ones. The motor doesn't know the difference between pedaling while using the throttle, or pedaling while using cruise control -- it's all TAB either way. Tora explained it in a video, that cruise control is the same as using the throttle as far as the controller is concerned.

That being the case, this test couldn't be done as you describe, because as soon as you start pedaling, you're in TAB, using way more current. The test would have to be pedal assist at a given level (2, in your test) while maintaining a steady speed, and cruise control without pedaling, at the same speed.

Who knows, I might give it a try. I've got an easy, mostly level 6 mile loop in my neighborhood. Since it's a loop, you'd be in the breeze from every possible direction. Run it several times in pedal assist and again on cruise control without pedaling and see what the results look like. Control for battery state of charge, tire pressure, ambient temperature, just like you did. Could be fun.

On my Pedego, this test could be done in two ways. The throttle automatically overrides the PAS no matter what level you're in. Or, you can turn off the PAS and use throttle only mode.

The trick is to minimize speed changes and avoid current spikes. Any method that accomplishes this should increase efficiency and extend range to some extent.
 

JRA

Well-Known Member
you have cruise control?

Cruise control function has been available for years for hub bikes. I use it all the time on my e drop bar bikes. Get up to speed and hold the throttle for 2 seconds and let go and pedal away in sync with the output allows for the wattage to go up or down according to minor changes in elevation and rider input and you stay about the same speed. It's how I get away with no PAS on those bikes and just use the drivetrain as normal with no motor input but the motor is putting out consistent power and as a benefit you are always on the power band with eliminating the dead spots at the top and bottom of the pedal stroke. I also find it to be very efficient overall.
 

vincent

Well-Known Member
I have always gotten really good mileage on my throttle only bikes and suspected it was more efficient than pas
Thanks for writing that up
 

6zfshdb

Well-Known Member
On many bikes without voltage compensating controllers, the level of PAS assist lessens with battery voltage drop. Using a throttle as described above can compensate for this loss of PAS effectiveness.