System (U, Motor, Controller) Efficiency

[vkruger]

1. Efficiency (Watts/mile): 10 to 12W/mi, depending on how many red lights
2. Speed (mph | kph): Typical average, 14-16 mph, city 23 mile daily commute round trip
3. Gradient (%): moderate hills, biggest 1 mile at 7-9% (have to brake at 45MPH going down)
4. Pedaling effort (none, light, heavy, extreme): medium (motor off above 18mph because of 20" hub wheel)
5. Bike Type recumbent Giro 20
6. Motor Model: BMC V1 geared
7. Controller Model: Crystalyte analog 35A
8. Battery (Voltage/Capacity): 36V - Various LiFePo4 10Ah 20Ah duct tape, Konion 8Ah 12Ah

[cerewa]

This is for the commute I used to do. The motor's controller broke and I switched jobs, and these days I commute without a motor.

1. Efficiency (Watt-hours/mile): 6 - 7 watt hours per mile
2. Speed (mph | kph): 16mph (65 minutes each way, 17 miles each way)
3. Gradient (%): lots of hills, 10% of the distance on flat ground. lots of ~%5 grades, some climbs of ~150 vertical feet in a space of ~1500 horizontal feet (10%).
4. Pedaling effort (none, light, heavy, extreme): medium-heavy
5. Bike Type: mountain bike
6. Motor Model: Cyclone 500W
7. Controller Model: Cyclone 24V, built-in to motor housing (intended for 30A max, I believe)
8. Battery (Voltage/Capacity): YESA 240 watt hour (24V10Ah) LiFePO4. Enough capacity to go about 40 miles with this setup. 20A limit on BMS.

[Toshi]

i think this is an admirable effort. however, i don't think it can be used for straightforward comparisons between gear, as bike configuration (including handlebar/seat height! and tire choice), rider weight, terrain, number of stops/starts, presence of a headwind or tailwind, pace, and riding style/pedaling effort play a HUGE role. i could use 0 Wh/mile with my current setup and have used as much as 37 Wh/mile, after all.

that said, here are my data:

1. Efficiency. 25.89 Wh/mi lifetime average as of today. Scatter plot of energy use over time.

2. Speed. I cruise on the flat at 22-25 mph but my CA-reported average is almost always 15-17 mph due to hills as well as many stoplights and stop signs along my route.

3. Gradient (%). My normal route has 250 feet of vertical gain over 1.22 miles: an average grade of 3.88%. There's a short pitch in there that's probably a 5-6% grade.

4. Pedaling effort. Moderate. My bike is geared such that I can pedal along at a reasonable cadence whether going 5 mph or 30 mph.

5. Bike Type. Flat-bar hybrid with 26x1.75" semislick tires, with handlebars about level with the seat.

6. Motor Model. Crystalyte 407 in a 26" wheel.

7. Controller Model. Crystalyte 72V 20A pedal-first controller.

8. Battery. 48V 12Ah prismatic ebikes.ca LiFePO4.

[bbushwacker]

1. Efficiency. 29.7 Wh/mile 18.5 Wh/km (average, going both directions)

2. Speed. max 34km/h

3. Gradient (%). pretty steep, estimated 100m elevation gain over 1km, rest flat

4. Pedaling effort. Minimal, only on hills, throughout acceleration and to pass others

5. Bike Type. Heavy full suspension downhill frame with knobby off-road tires

6. Motor Model. Ezee, rear with disc

7. Controller Model. Ezee, limited to max 17A min 39V to reduce the risk of frying more MOSFETs

8. Battery. 48V8Ah NiCd

[floatbike]

1. Efficiency : 14 WHr/Mi
2. Speed (mph | kph): 20mph max, 16mph cruise
3. Gradient (%): flat with a few steep hills
4. Pedaling effort (none, light, heavy, extreme): moderate pedaling all the time, heavy up hills
5. Bike Type (roadster, MTB, trike, others): 24lb aluminum folder
6. Motor Model: GoldenMotor Geared Mini Motor
7. Controller Model: GoldenMotor Cruise Controller with Regen
8. Battery (Voltage/Capacity): 38.4V 10AHr GoldenMotor LiFePO4

I used to race cross country MTB, now 15 years later I am slower with electric assist than I used to be unasisted!

[icecube57]

1. Efficiency : 18-24wh per mile
2. Speed : 30mph on flats 36mph down hill
3. Gradient : 1-2% on the trail that I ride
4. Pedaling effort : Light Pedaling
5. Bike Type: Next Mountain Ridge MTB
6. Motor Model: Golden Motor 1000w
7. Controller Model: Golden Motor Stock 48v 30A
8. Battery (Voltage/Capacity) 48v 20AH Ebay Duck Tape (NON PING)

[MartyK68]

It would've been nice to see everybody's weight...

[urace4me2]

Just did a test yesterday:
1. Eff: 11.5 watt hour per mile 37.5 miles, 1:48, batteries never quit even though the last 3 miles or so I didn't pedal at all. so actual achieved efficiancy was higher and could have been much higher had I kept pedaling 'til batteries got below low volt controller threshold.
2. Spd: 24mph was the max speed I could feel the motor helping. Top speed by myself with motor turned off was 28 mph on the flats. After 30 miles I could still get 21 on the flat without pedaling.
3. Gradient: dead flat.
4. Pedal effort: Extreme. 90% of the ride was pedal unassisted for 10 to 60 seconds then use a electric burst to rest for 10-60 seconds. Probably less than 50% assisted time. Used pedals to get rolling but motor to help get from 4 mph to 20mph.
5. bike: Giant Sedona ATX (1994) clipless pedals to allow "full circle" pedaling. 1.7 inch wide almost slick road type tires pumped to 60 psi
6. motor: Amped bikes kit
7. controller: Amped bikes kit
8. battery: Jupiter battery 3 X 12 volt 12 ah AGM SLA

Thrilled with the range!

[Russell]

Just did a test yesterday:
1. Eff: 11.5 watt hour per mile 37.5 miles,
8. battery: Jupiter battery 3 X 12 volt 12 ah AGM SLA

Thrilled with the range!

Hello urace4me2,

What are you using to measure the energy consumed from the batteries or are you giving us your TOTAL power (you and batteries) from a PowerTap hub? I ask because when folks here talk about efficiency the Wh/mile numbers are JUST what the batteries provide and there's no way 3-12V/12Ah batteries can provide 431Wh (11.5 Wh/mi x 37.5 mi) of energy unless they are discharged completely at a 20 hour rate.

-R

[urace4me2]

I did math assuming 36v12ah capacity (432 watt hr) spread over 37.5 miles. It assumes the batteries were totally used up. Of course this is false but it errors on the side of indicating less efficiency than actually achieved. It is the battery power I used up during my 37.5 mile assisted ride (assuming they quit on me, but they didn't). I think what's so different is I was putting out some serious watts with my legs. It was more a test of how far those batteries could "help" me maintain a speed average of over 20, while saving me from having to put out an all out race level of effort. Total run time was 1:48 but throttle was off for probably 50% of the time. I milked those SLAs really slow.

[Russell]

I did math assuming 36v12ah capacity (432 watt hr) spread over 37.5 miles. It assumes the batteries were totally used up. Of course this is false but it errors on the side of indicating less efficiency than actually achieved. It is the battery power I used up during my 37.5 mile assisted ride (assuming they quit on me, but they didn't). I think what's so different is I was putting out some serious watts with my legs. It was more a test of how far those batteries could "help" me maintain a speed average of over 20, while saving me from having to put out an all out race level of effort. Total run time was 1:48 but throttle was off for probably 50% of the time. I milked those SLAs really slow.

Urace4me2,

That's not a good assumption, but even if you did use them up (~10.5V/12V battery) SLA batteries are rated for a 20 hour discharge so if you discharge them quicker the capacity they deliver is significantly less. What I found was my SLA's delivered 60% of their rated capacity when discharged over a 1.5 hour ride, which is pretty standard. Temperature also affects how much capacity is available with 100% at 25C down to around 85% at 0C.

If you really want to measure how much energy you're using then you need either a Watts-Up meter or Cycle Analyst

http://www.rc-electronics-usa.com/ammeters/dc-amp-meter.html

http://www.ebikes.ca/drainbrain.shtml

-R

[urace4me2]

I see. Thanks Russell. At least I know I can do the 38 mile each way commute on a charge now, if I pedal. If I plug in your 60% guideline, the efficiency goes to 6.91 Whr/mile. I know it's just an estimate.

[Borromeo]

The first long-distance test:

1 ) Efficiency - ? Wh/Mile (How I can calculate?) Autonomy - about 37 miles (60 kms)
2 ) Speed - 12.5 - 19 MPH (20-30 kph) cruiser, top speed 20 MPH (32-33 kph)
3 ) Gradient - Almost completely flat
4 ) Pedaling - for starting only
5 ) Bike - mountain bike
6 ) Motor - "Red Flag" Chinese hub motor with Hall sensors
7 ) Controller - Chinese Unnamed
8 ) Battery - Gel Lead-acid 3 x 12V 12 AH

I was testing and changing the motor wiring and crossing the whole city, Buenos Aires

[ecat]

Just got back from a typical ride and looked at the numbers, so here goes:

1. Efficiency (Watts/mile) 13.7 Wh/Km
2. Speed (mph | kph) Average speed 29.4 Km/h. Top speed 50 Km/h
3. Gradient (%) 70% flat 30% hills, none steep
4. Pedaling effort (none, light, heavy, extreme) medium, I was quite warm when finished
5. Bike Type (roadster, MTB, trike, others) Catrike Expedition tadpole recumbent trike
6. Motor Model Ecospeed mid drive
7. Controller Model BMC
8. Battery (Voltage/Capacity) Ping 36V 20 AH. Used 9.21 AH to go 24.3 KM

Ecat

[fifthmass]

1. Efficiency : 12-20wh per mile
2. Speed : 23mph on flats 30mph down hill
3. Gradient : max 3-4% around Boston area
4. Pedaling effort : Light to moderate Pedaling 80% of time, 20% no pedal
5. Bike Type: crappy Walmart MTB
6. Motor Model: Clyte 408
7. Controller Model: Clyte 48v 40A
8. Battery (Voltage/Capacity) 48v 20AH Ping v1 LifePo4

Regards,
Bill

[jag]

1. Efficiency (Watts/mile)
18w/km = 28W/mile
2. Speed (mph | kph)
40-50km/h
3. Gradient (%)
Some small hills up and down the river valley.
4. Pedaling effort (none, light, heavy, extreme)
medium
5. Bike Type (roadster, MTB, trike, others)
Mtb with city slicks.
6. Motor Model
Nine Continent 2809
7. Controller Model
Crystallyte 30A pedal first
8. Battery (Voltage/Capacity)
72V 8Ah NiCd

Martin

[Reid Welch]

1. efficiency: 19 to 20 Wh/mile
2. speed: 20mph
3. gradient: flat
4. pedaling: none
5. bike: steel chinese cruiser 52T front, 16T rear
6. motor: 26" eZee, Bontrager Big Hanks slicks front and rear, 10PSI and 20 PSI, respectively.
7. controller: standard supplied eZee 20A.
8. Battery: 36V/20Ah Ping
9. Cycle Analyst presently set for 13A max to save start-up current. Cruises at about 9A @20mph,
riding style: full upright, leaning backwards, pulling against the long (reversed stem) handlebars.
10. Riding style: wasteful, WOT from starts.
11. Suspicion that planetary geared motors are a bit lossier at cruising speeds than direct drive,
and less lossy at start ups and when lugged.
12. Freewheels great. I will pedal more as I get my bicycle legs again.
13. Fixed gearing about ideal for pedal assisting up to about 23mph.
14. C.A. could be set for 20mph max (or whatever), at which point there is no electric consumption (no aid from motor).
15. Unloaded speed of the eZee with this pack is about 28mph; so I have that option of e-assist up to that speed if I spin like mad. So I have it set for "30mph", to always have some help from the eZee if I happen to feel like spinning pedals.
16. Bike has only 110 miles on it at present and the motor is partially oil filled with ATF.
I hope for =a bit= greater motor efficiency with break-in, with possibly less oil in the fill; less oil churning at the ring gear,
and, of course, reduced power consumption when I add pedal assist.
17. At present am having most fun just going pure electric, but that will change and Wh/mile will decrease in proportion as I grow less lazy-legged.

[fabiograssi]

Sorry about the noob question, but I saw in this topic some setups we have 72v controllers with 48 or 36 volts battery packs. Is that possible? The controller don't cut off the power because of the low voltage? Need some mod? Or the users that mentioned 72v controllers are, in fact, the 36~72 volts controllers (the ones that accept more than one fixed voltage input)???

[aaronski]

On Road:
1. efficiency: 15 wh/mi
2. speed: 16mph average
3. gradient: 5% up down constant
4. pedaling: medium
Off Road
1. efficiency: 35 wh/mi
2. speed: 7mph average
3. gradient: 10% up down constant
4. pedaling: light
5. LOTS of starts and stops due to riding with DOG. no coasting downhill either, can't go over 7 mph at all.(her top speed)


General:
5. bike: 22#alu full suspension mtb
6. motor: 26" BMC, Specialized Armadillo, 60 PSI
7. controller: standard supplied BMC 30 A
8. Battery: 48v 10ah from Cycle9.com

[alan]

22 mile round trip commute 4-5 days/week

1. Efficiency: ~14 WH/mile (battery always strong at end, but assume 7/8ths used per display showing 1 of 8 battery bars).
2. Speed: 18-22 mph (I maintain speed the whole way).
3. Gradient: mostly flat, except for half dozen over/under passes
4. Pedaling effort: full power starts and climbs, regen decelerates, medium pedaling mostly
5. Bike Type: Univega Alpena chrome-molly front suspension/hardtail MTB with Michelin City 1.75"x26" tires/fenders
6. Motor Model: Bionx 350 PL
7. Controller Model: Bionx 350 PL
8. Battery 36V, 9.8AH
9. Bike+rider weight: ~225 lb

[wildnrg]

1. Efficiency (Watts/mile)
9w/km (14.4w/mile)

2. Speed (mph | kph)
45km/h flat, 25km/h 2% up, 61 km/h 2% down.

3. Gradient (%)
Max % Untested

4. Pedaling effort (none, light, heavy, extreme)
Light

5. Bike Type (roadster, MTB, trike, others)
Dual suspension MTB

6. Motor Model
Headline (Cyclone) 500w

7. Controller Model
24A internal

8. Battery (Voltage/Capacity)
24V 20AH

[gerlewis]

You guys quoting your speed via a bike-speedo, have you calibrated it for your wheel circumference? As I found mine was over reading out of the box. I was getting 48kph when in actual fact 44 is the true speed after calibration. Which was annoying as I thought I was doing 30mph.

Ger

[patrickza]

My results after 1000 miles

1. Efficiency (Watts/mile)
11wh/km (18wh/mile)

2. Speed (mph | kph)
30km/h

3. Gradient (%)
Fairly major hills, steep enough that I don't freewheel going down as it's too fast for comfort.

4. Pedaling effort (none, light, heavy, extreme)
Light

5. Bike Type (roadster, MTB, trike, others)
Dual suspension MTB

6. Motor Model
Crystalyte x5305

7. Controller Model
Crystalyte 72v48A

8. Battery (Voltage/Capacity)
72V 10AH

[LI-ghtcycle]

Ok, here's my best run thus far:

1) 42 miles

2) Average speed 13MPH (lots of hills, some stretching over 2 miles)

3) Gradient 3-7%

4) Moderate Pedaling

5) Hardtail (Rigid Frame Mid/Late 90's Nishiki w/ Marzocchi Fork) Mountain Bike turned "Dirtable" street bike

6) Amped Bikes Geared (rear wheel) Motor Kit

7) Amped Bikes 15/22Amp controller

Dewalt A123 battery pack (28V packs, 2s4p) 53Volt 9.2AH

This is with about 70% pedaling only, I have found I can use the motor to get up to speed and carry it just pedaling, and minor hills I usually just pedal, but my battery is mainly my "get home happy" device, meaning I get a good work-out, sweat a bit but still can walk when I get home!

[skeetab5780]

that's slightly scary....that's exactly my best run also....same mileage, stats, hills and pedaling.

except i use a 48v 10ah lifepo4