System (U, Motor, Controller) Efficiency

[aaronski]

here's some interesting stats: 9c 20" wheel, 10 ah lifepo batt. 12 fet Lyen controller. commute is 7 miles.

average with controller set to 24A is 3.1 AH per ride
Average with controller set to 70a is 5.7 AH per ride

average speed is the same. 17 MPH.

[DAS100]

This is my first post, and I’m glad I could contribute. I recently completed building my first electric bike, and last Saturday went on a 45 mile trip with it. The bike has a Cycle Analyst and I confirmed the speed and mileage the CA displayed using a GPS. The following information is based on the 45.37 mile trip I took.

Facts about the trip:
The trip started in North Phoenix. I rode to the middle of downtown Phoenix, then to downtown Scottsdale, and then back to the location I started from (using a different path). I used Bike Paths as much as possible. There was a moderate amount of stopping and starting for street signals & signs, traffic etc.

1. Efficiency 22.6 wh/mi
2. Speed: I cruised generally at 15-18 mph, occasionally slower 7-12 mph (~7% of the time) when going over rough terrain, or sight seeing. (I did a speed run, and reached a top speed of 27.2 mph on flat terrain). CA indicated an average speed of 12.1 mph for the entire trip (CA does not include the time when the bike isn’t moving, but does include anytime the bike is moving, (even if walking it across a crosswalk).
3. Gradient: Flat
4. Pedaling: None
5. Bike: Inexpensive Mongoose XCom 700cc Men’s Bike with thorn resistant tubes, and tire sealant. Total Weight of Bike, Equipment, and Rider is 335 lbs.
6. Motor: 9C 2807 (ebike.ca)
7. Controller: Infineon Controller 25Amps (ebike.ca)
8. Battery: 48 volt 20 Amp V2.5 Ping Battery


Total Amperage drawn from the battery during the trip was 19.95 amps. I stopped at about 35 miles and charged the battery with a 5amp charger for 55 minutes, just to make sure I had enough juice to make it home.

Cruising on level smooth ground at 16-18 mph (no stops) and no pedeling, I’m averaging about 17-19wh/mile.

Hope this helps.

[kentlim26]

hi minde28383,

I pedal almost nothing, max is 5%. my this throttle is 3/4 Plus ( but will not hit full throttle), the speed will run easily 42km/h. Im weight only 65kg ~ 68kg. Most of road is very flat, if there is slop, the slop will be less then 10degree, >200meters. PSI air pressure on tyre is 50 ( i think this helps too ) most of my time, i am taking 12+ watts/ km. 9C magnet size i heard is 28mm, for this CHM motor is 32mm. I think it makes a different. I have open up hub motor once to repair the hall sensor, so at the same time i also measure the magnet size.

The most interesting discovery for this efficiency, i had also compare with cammy_CC 48v 500watts kit. I plug in my Turnigy meter and do a testing for full throttle is 40km/h max, but it will takes 15.44watts/ km at least. said to be a small motor, should be taking lesser in watts/ km but it didn't. i also wondering what is the watts/ km for 36v 200watts kit ? im living in singapore, land is almost 75% - 80% flat.

cheers
kentlim

[pcarlson79]

Hi Well I have 2 eBikes. One for everyday work commuting, must be silent and reliable, and a FUN bike

Work Commuter:
1. Efficiency: 19-21 watts/km
2. Speed: 31kph coast up to 40kph peddling
3. Gradient: very small hills
4. Pedaling effort: Moderate
5. Bike Type: Giant Mountain bike, hard tail, steel front forks with no suspension. 21speed
6. Golden motor 36v 500w
7. Controller: Kelly KBS72121 (24v-72v 50A controller)
8. Battery: Ping 36v 30Ah. Gives about 70Km range



FUN eBike:
1. Efficiency: 28-35 watts/km
2. Speed: 55kph coast up to 75kph peddling
3. Gradient: ANYTHING
4. Pedaling effort: None, peddles spin too fast
5. Bike Type: Dual suspension mountain bike 5 speed rear de-reullaeur (spelling?)
6. Cyclone 1200w 3 chainring kit. Draws 1800watts constantly
7. Controller: Standard Cyclone 1200w controller
8. Battery: Conhismotor 48v 25Ah. Gives about 40Km range at full throttle

[Cold-E-Commuter]

Here is the spreadsheet I have created. Hope this is helpfull. Let me know what you think.

Ride Log.xls

(3.2 MiB) Downloaded 226 times

You will need to unhide rows and columns as needed.

[Cold-E-Commuter]

Speadsheet downloaded 8 times! No comments? Wow, is it that bad?

[edcastrovalley]

Speadsheet downloaded 8 times! No comments? Wow, is it that bad?

Actually this is a really nice spreadsheet. It's a good snapshot of winter riding with lots of information here. I especially like the cost per mile column. You would have to go 100 miles to rack up 2 cents in electric costs. I'm curious as how you are measuring your charger kwh to get charger efficiency.

[Cold-E-Commuter]

I am measuring the charger in two ways. I have it plugged into a Kill-O-Watt from the wall and a Watts-Up going into the battery. That is where the info comes from. A bit intensive to keep all the data updated after each ride, but worth it to me.

[Cold-E-Commuter]

Wow, now 25 downloads but only one comment. I hope this wasn't a waste of time for everyone.

[Cold-E-Commuter]

edcastrovalley, I have recently reviewed a post viewtopic.php?f=14&t=14934 and think that my calculations for charger efficiency are wrong. Doctorbass brings forth the "PF" indicated factor and this charger appears to be only 35 or 36 % according to the PF on the Kill-O-Watt. I have been calculating it based upon Kw used (via Kill-O-Watt) compared to input into the battery (via Watt's Up). For example, line 50 of the spread sheet shows .69 Kw used (or 690 watts) and 547.2 watts input into the battery. Yes this appears to be 79% but I am sure there is more to it than that. Here is a pic of the charging station.

100_1428.JPG

(190.29 KiB) Downloaded 3 times

As you can see, the Kill-O-Watt measures from the wall to the charger and the WU measures from the charger to the battery. Hope this helps.

[LI-ghtcycle]

I think I might have something worthy of contribution here, no idea what the margin of error might be with the Turnigy Power & Watt Meter, but yesterday I hauled a kiddy trailer behind the bike using a Amped Bikes 9 x 7 DD rear hub motor to go 30 miles with an average speed of about 13 MPH according to the trail tech, I was shooting for about 18MPH most of the time just my eye-ball, lots of hills, some up to 10% grade, most closer to 4-5% and I had about 50lbs of gear + the kiddy trailer to haul my newly built nuvinci wheel.

I went really conservative since I had no idea what my range would be with this set-up, and pedaling was about as much as I can on a long trip with this kind of weight (amazing how much difference that trailer makes, with this same weight on my back it wasn't half as difficult! ) so I tried my best to keep the draw around 200 - 250W most of the time, and for the hills I had a peak of 1000W, but most of the time just 400-700W was enough to go up the hills, but I was beat after this trip, not so much hard pedaling, as marathon moderate pedaling.

Here are the basics:

1. Efficiency: 13 Watts/Mile
2. Speed average 14 MPH on the computer (my normal cruising speed was about 18MPH, pedal starts only, no power used until up to 10+ MPH)
3. Gradient 4 - 10% with lots of small hills in-between with a coulple 2 - 3 mile long moderate hills, and the big momma, about 2 miles of 5 - 12% at the end.
4. Pedaling Strenuous, moderate pedaling, but for 35 miles
5. Bike Type: Tidal Force frame with Rigid Big Dummy Forks, Schwalbe Big Apple Tires, 18Speed standard gearing with an extra low gear (28T) up front.
6. Amped Bikes 9 x 7 DD Rear hub motor (Very Early 2007 model, still has the "9C" logo on the controller)
7. Standard 9C 20A controller that came with the kit circa 2007
8. Battery: 12s (45V Nominal) Turnigy Nano Tech 25 - 50C 12AH size. Used just 7 almost 8 AH's of the 12AH pack for this trip.

P.S. this is with a 170lb rider, 80lbs of cargo (30lb trailer and 50lbs cargo on it, and the drag added by the trailer .. HATE trailers ... ) and 63lb bike.

[montyp]

Here is the spreadsheet I have created. Hope this is helpfull. Let me know what you think.

Ride Log.xls

You will need to unhide rows and columns as needed.

Wow - that is a lot of data. I really like how your listed *all* the costs of building the bike. I think I have overlooked a couple :p

In the cost comparison are you showing the purchase price and operatering cost will break-even with just the gas from operating the car, correct?

I've been trying to convince

[Cold-E-Commuter]

Yes, the comparison is offset cost off gasoline only for a vehicle getting 19.5 mpg. The mileage and cost of gas will of course affect the mileage required to reach break even. I hope all of the data makes sense and is somewhat accurate. I have not heard anything other than maybe the PF is causing a false reading in the actual charging cost. I felt it necessary to include all of the costs because, well, I am anal about that sort of thing.

[motornews]

from the other posts i think that my numbers will be very good.

1.dont know how to calculate
2.48,5 kmh top speed on flat(on downhill just 53kmh???strainge)
3.97% flat
4.pedalling-non
5.mtb average
6.chinese gm(advert--1000w)
7.controler from golden motors cn(has cruise control-very enjoyble)
8.batt-48v 9 ah -sla-

doing 19-20 kmh on charge,with the slas think its nice
bike weights 35kg+78 FRESH MEAT total -113

how can i measur the -efficiency-?

[Scottyf]

1. Efficiency 8-10 whrs per mile
2. Speed (15-18 mph)
3. Gradient mixed
up to 10%
4. Peddling effort always moderate
5. Bike Type road
6. Motor Model bafang 250watt front driving
7. Controller Model universal 15amp peak

8. Battery panasonic cell 36v 9amp hr

[Bike_on]

1. 20 whr/mi
2. 24-25mph
3. mixed grades, 1300 ft gain.
4. moderate-hard
5. Optibike 850
6. Motorized bottom bracket
7. Optibike proprietary
8. 36V, 20 ahr LiCo

Stats
Giant Lite Optibike Optibike Optibike
2007 2008 2009 2010
Total Bike Miles 3231.8 4016.0 3661.8 4975.2
Total Bike Hours 197.0 185.3 159.7 233.8
Total Average 16.4 21.7 22.9 21.3

Commute miles 2398.5 3087.7 3452.65 4510.0
Commute Hours 139.4 134.2 147.33 198.4
Commute Average 17.2 23.0 23.4 22.7

Total Commute Days 87.0 88.0 92.0 115.0
Estimated Working Days 235.0 230.0 230.0 230.0
% Commuted 37.0% 38.3% 40.0% 50.0%
% bike miles for Commute 74.2% 76.9% 94.3% 90.6%

Equivalent FULL Commutes of 42+ miles 45 59 75.75 100
Equivalent commute rides of 21+ miles 90 118 151.5 200
Actual commute rides of 21+ miles 48 98 130 172
Actual commute rides of 15+ miles 5 4 4 0
Actual commute rides of 10+ miles 42 24 33 55
Actual commute rides of 5+ miles 68 20 8 2

Number of weeks of 100+ miles 14 19 16 37
Number of weeks of 200+ miles 0 5 2 0

Savings: per round trip $22.3 $21.4 $21.3 $21.3
Total Savings $1,001 $1,261 $1,613 $2,130

[FFR Trikes]

1. 20.6 wh/mi
2. 30.5 mph average speed on a 16 mile ride
3. rolling with some moderate hills in western North Carolina
4. Medium-heavy
5. KMX Tornado
6. Astro 3220
7. CC HV160
8. 44.4V 25 Ah LiPo

This was on my personal FFR Transition One.

Upgrades: Schlumpf HSD, 6T Astro 3220, prototype tailfairing

The tailfairing made a pretty significant difference. I do almost all of my riding at full throttle, which is 31-32 mph. Typically I see efficiencies around 25 wh/mile. The tailfairing dropped that number to 20 wh/mile on it's first run. We'll be doing more development with carbon tail fairings in the future.


-Tommy

[Skippic]

Very interesting stuff. Maybe we could do another thread setting as many parameters as we can, so as to restrict the number of variables.

For example:
Constant speed
No wind
No hills
No pedaling

1. Instant watts used at 10, 15, 20... [mph]
2. Bike Type (roadster, MTB, trike, others)
3. Motor Model
4. Controller Model
5. Battery (Voltage/Capacity)

I understand this is only for people with a CA or a watt meter, but it would provide a way to compare the efficiency of different setups.

[veloman]

1. Efficiency: 10-13 wh/mile
2. Speed: 15-18mph depending on grade, usually at 17.5mph on the flats
3. Gradient: 0-12%, varies much, but if hilly I pedal a LOT more, so it evens out.
4. Pedaling effort: moderate on hills and starts, none on flats
5. Bike Type: Mongoose Sycamore rigid mtn bike
6. Motor: cellman's MXUS 250w geared hub
7. Controller: 13.6amp peak 36v
8. Battery: 36v 11ah lifepo4 pouch (don't know name)

I've had as low as 6 wh/mile when pedaling about 50% of the time and nearly flat conditions. I think that was my first ride on it and I babied it since it was wet out. 12 wh/miles seems to be the standard. I use to get 16wh/mile on a completely different setup, 450w unite driving the cranks with barely any pressure on the pedals, averaging 22mph.

[GaryJS]

Time for me to clock in with my values from my first clocked ride

1. Efficiency: 11.16 wh/mile
2. Speed: average 16.3mph
3. Gradient: -14 to +13%
4. Pedaling effort: low to moderate (mixed)
5. Bike Type: Raleigh Mountain bike
6. Motor: vpower 24v 250w motor (unsure who actually makes it or real rating? - see pics in build thread)
7. Controller: Vpower 24v 250w controller (unsure who actually makes it or real rating? - see pics in build thread)
8. Battery: 36v 12ah SLA

Build thread: http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=30405&p=439497#p439497
Route: http://maps.google.com/maps/ms?ie=UTF&msa=0&msid=211150202879810676935.0004ad6e4540615caefe0 (had to stop a couple of times for my lycra clad friend to catch up

[Hugues]

my turn


1. Efficiency (Watts/mile) = 47 (that figure seems to be on the high side compared to other posts, )
2. Speed (mph ) = 16
3. Gradient (%) = 10
4. Pedaling effort light
5. Bike Type MTB
6. Motor Model Crystalyte HT (something)
7. Controller Model Infineon 40A
8. Battery 72 V 10 ah

[Danos]

Numbers from my short (4.7km) commute to work. Short steep climb then descent with some flat. Mostly WOT with moderate pedaling.

1. Efficiency (Wh/km) = 18
2. Speed (kph) = max 52kph
3. Gradient (%) = up to 10%
4. Pedaling effort: moderate
5. Bike Type: MTB hardtail Trek 4100
6. Motor Model: Mac 500w rear
7. Controller Model: Infineon 30A
8. Battery: A123 16s4p 58V 9.2ah

[LI-ghtcycle]

Just wanted to move some Efficiency info from my earlier build thread here:

http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=25082&hilit=mid+drive&start=45

And here is a basic thumbnail of the info:

Distance: 8 miles

Average slope: 3 - 12%

Watt Hours Per Mile: 10.75 (86 WH's for 8 Mi. )

Amped Bikes 9 x 7 DD rear hub motor used as mid-drive, using 1/8th bicycle chain from motor to NuVinci rear hub with a 3 to 1 single stage reduction (13T to 27T, using track a cog on hub motor and sprocket from Staton Inc.) with an effective gearing range for 7 to 30 MPH.

And now my latest build, I have done a longer trip to include the same hill with the exception of the few blocks of 10+ % grade hill (my gearing is too tall, have to wait to get proper gearing to get the full potential of this new motor) and using even less Wh/Mi.

Here are the stats:

Distance: 42 miles

Average slope 3 - 10%

Watt Hours Per Mile: 8.7

(This second test was on a day with virtually no wind, at at about 56F temperature)

[cwah]

I don't have a cycle analyst. But I manage to do that:
Max distance: 18 miles total distance on throttle only (mainly flat road)
Max speed: 23mph (but most of the time I'm between 15 and 23 mph)
Average: 14 mph.
Battery: 36V10A Li(NiCoMn)O2

Is it good efficiency?

[gartmu]

1. Efficiency (13Wh/mile)
2. Speed (16mph )
3. Gradient (total climb: 582 meters vertical; total descend: 597 meters vertical)
4. Pedaling effort (none)
5. Bike Type (MTB)
6. Motor Model (Bafang BPM 48V500W Code12)
7. Controller Model (KU123 500W 12Mosfets 48V 28A)
8. Battery (Headway 48V 9AH)

My bike weights 25kg and I weight 83Kg. My height is 1,82 meters.