Range: Fact vs. Fiction

[Rick Speicher]

When shopping around for an Ebike, one of the main concerns is range. Running out of power several miles from your recharge site is a bit of a pain, and for some with disabilities, it is simply not an option. I work with a lot of different Ebikes, from high end European makes to lower priced Asian makes, and a lot of DIY stuff. And what I see is a lot of exaggerated range claims by all, some extremely exaggerated! Most folks I know state there range in terms of Watt Hours per mile, Wh/m. This seems to be a good way to compare all Ebikes, no matter the make, battery voltage or motor power. On average, I have found that I typically get about 1 mile per 20 Watt hour, 20Wh/m. This is a classic case of 'less is more', in that, 15 Wh/m is better milage than 20 Wh/m, so a lower Wh/m number is a good thing! I commute daily about 50 miles, and try as I might, being an athletic peddler, I have never gotten better than 18.7 Wh/m. Yet I see some new European makes claiming less than 5 Wh/m!! This totally pegs my BS meter! So my question to all of the good and knowledgeable people here at EBR is, What kind of range do you get? Please share your range numbers, and please be honest, as this is an effort to help others, some with disabilities, to choose a bike that will truly deliver the range they have to have to make it home safely. For those who do not understand the math, here is how it works. Multiply the battery capacity which is usually stated in Amp Hours, Ah, by the battery voltage in volts V, to get Watt Hours, Wh.
For instance, my battery is 52v x 11.5Ah = 598 Wh. Then simply divide Wh by your mileage, 598Wh / 32miles = 18.68 Wh/m, which is my personal best. Keep in mind that this number will vary based on terrain, load and speed. I live in a steep hilly area, weigh 200+ and like to go 20mph on average, so the same setup will yield better mileage on the flats with a lighter rider going slower. What's your best ?

 

[Amanda]

I have short commute, but got 80km (best guess based on the fact I've only ridden the past month or so with winter weather permitting) on my Surface Rook 604.

If you can explain how to calculate the watt hours I can try to figure out the metric you've adopted

 

[Rick Speicher]

I have short commute, but got 80km (best guess based on the fact I've only ridden the past month or so with winter weather permitting) on my Surface Rook 604.

If you can explain how to calculate the watt hours I can try to figure out the metric you've adopted

Well, 80 Km = 49.7 miles. What is your battery voltage and capacity?

 

[Ravi Kempaiah]

When shopping around for an Ebike, one of the main concerns is range. Running out of power several miles from your recharge site is a bit of a pain, and for some with disabilities, it is simply not an option. I work with a lot of different Ebikes, from high end European makes to lower priced Asian makes, and a lot of DIY stuff. And what I see is a lot of exaggerated range claims by all, some extremely exaggerated! Most folks I know state there range in terms of Watt Hours per mile, Wh/m. This seems to be a good way to compare all Ebikes, no matter the make, battery voltage or motor power. On average, I have found that I typically get about 1 mile per 20 Watt hour, 20Wh/m. This is a classic case of 'less is more', in that, 15 Wh/m is better milage than 20 Wh/m, so a lower Wh/m number is a good thing! I commute daily about 50 miles, and try as I might, being an athletic peddler, I have never gotten better than 18.7 Wh/m. Yet I see some new European makes claiming less than 5 Wh/m!! This totally pegs my BS meter! So my question to all of the good and knowledgeable people here at EBR is, What kind of range do you get? Please share your range numbers, and please be honest, as this is an effort to help others, some with disabilities, to choose a bike that will truly deliver the range they have to have to make it home safely. For those who do not understand the math, here is how it works. Multiply the battery capacity which is usually stated in Amp Hours, Ah, by the battery voltage in volts V, to get Watt Hours, Wh.
For instance, my battery is 52v x 11.5Ah = 598 Wh. Then simply divide Wh by your mileage, 598Wh / 32miles = 18.68 Wh/m, which is my personal best. Keep in mind that this number will vary based on terrain, load and speed. I live in a steep hilly area, weigh 200+ and like to go 20mph on average, so the same setup will yield better mileage on the flats with a lighter rider going slower. What's your best ?

I get 12-15 Whr/mile.
So, anywhere from 25miles to 35 miles per charge on Bosch 400Whr powerpack or 50-60 miles on Stromer ST2 with ~800Whr battery.
This is mostly city and on long traffic-free trails, the consumption stays at 15-16Whr /mile because of higher speed/drag.

 

[harryS]

I use a wattmeter that I'll occasionally hook up between the battery and the controller to check my "mileage". It's all about how fast you go, and how much weight you push.

My geared hub motor bikes will burn 10 wh/mile if I keep my speed below 14mph in the lowest PAS levels. Same speed at higher PAS will take me up to 14 wh/m.

My Bafang BBS02 mid drive is about 15 wh/m at 14 mph, and 20 wh/m at 18 mph.

I run one of my ebikes on various batteries ranging from 36V tool batteries to a 52V mini. If the speed is kept the same, the wh/m is about the same.

Also, rolling resistance will affect power consumption. If the bike is harder to pedal, with knobby tires and higher weight, it should use more power.

 

[J.R.]

I regularly do 40 mile rides with another member here, on my Easy Motion 29'er with 417 wh battery. We will also do some 50 mile rides, but planning is all important to have the power left to complete the ride. Keeping average speeds at 15-16 mph, 10 wh/mi. 12 mph, 8 wh/mi. And if I go for speed 20-22 mph, 15wh/mi.

I'm not entirely sure all manufactures are lying, they're likely giving best case stats in most instances. With a regular push bike on a commute I can average 13-14 mph, and if I keep an ebike at that speed I can get sub 10 wh/mi.

 

[mrgold35]

I have a Radrover 4" fat tire eMTB with 750w hub motor. My specs are: 48v X 11.6Ah = 556.8Wh

I went on a 25 mile ride on Sunday at PAS-3@350w max power (556.8Wh / 24.5 miles = 22.72 Wh/m). My speed varied between 12 -16 mph at PAS 3 depending if I was on single track trail (hard pack to loose sand) or paved roads during my ride. I was still at a solid 1 bar (around 20%) of power when I got home a few hours later.

I tend to use more power than most because:
- my weight at 270lbs
- 4900ft to 5400ft elevation during ride
- mid 30s temps in the morning during ride
- usual head wind of 5-8 mph 1/2 of my ride
- +70lbs of bike, rack, rack bag, lights, suspension seat post, extra gear
- extra weight of cold weather riding gear
- took the wife's Radrover battery just in case @ 7 lbs
- Knobby off road MTB tires on asphalt/concrete 90% of the time

I like the Radrover as my weekend fun ride and weekday commuter bike because it can transition from anything like loose sand, mud, hard pack trails, asphalt roads/bike paths, concrete side walk, jump up/down curbs, and ride over most obstacles without missing a beat. The fat tires adds to the suspension to help smooth out the ride along with adding a supension seat post. Might come in handy for a handicapped person if they need to ride in different types of terrain during their commute.

 

[Alan Acock]

I have a Trek XM700+. I did a 50 mile ride using a 400 watt battery. I was in the ECO mode (lowest level) for 90%+ of the ride. The loaded bike weighs just under 50 pounds and I added 210 pounds. I still had an "estimated" 10 miles left on the battery.

 

[John French]

I exhausted my Bosch Powerpack 400 at about mile 38.5 a few months ago. That would be 396 wh/38.5 = 10.3 wh/mile. Haibike XDuro Race, total weight about 300 lbs (bike plus rider), hilly ride, maybe 60% Eco mode, average speed about 14-15 mph. Just got a Powerpack 500 and used about 1/2 of it on a similar 25-mile ride yesterday (which would also be about 10 wh/mile), and it does appear that the Powerpack 500 does give me 20% more range, for what it's worth.

 

[JRA]

I have tried to introduce this equation here a few times, glad to see it finally become part of the conversation. The reality is that your wh/mi depends solely on you and your bike and the terrain and surfaces you ride. If you take the time to understand this then your range anxiety issues should be put to rest. Range estimates by the manufacturers are best case scenario and if you know how many wh/mi you ride at then it is easy to calculate how much battery Wh you will need.

I find that knowing the Ah's used during the ride is key to my getting home with the batteries energy all but depleted. By monitoring it I can closely estimate my range on the fly and although I have arrived back with very little battery left, I have never come back having a completely dead one.

I live in the country and ride a variety of road surfaces, pavé, gravel and trail, and conditions (hills and headwinds). I also ride in a city and achieve similar wh/mi figures. 15 mph in the city is my average, stopping and starting a lot does eat at your Ah's though. Also I use a throttle only and have a cruise control function that I can set when cranking out the miles.

These are some examples of my ride data as provided by my Cycle Analyst:






The last one was strictly pavement, mostly level rough country type road, with a light tailwind using as low a wattage as possible (around 250w IIRC) set on cruise control and pushing the appropriate gear to maintain 20ish mph. At speeds above 20 mph I find that even with the same amount of pedaling effort wind resistance plays a big factor, but one you can also factor in to your equation based on your riding.

 

[Luv2ride]

I rode 71 miles using two batteries this past XMAS. Here is a link to my ride.
The harder I work the more range I can get.
https://www.strava.com/activities/811296956

 

[Peter Polling]

Interesting! I am Dutch, so I use the metric system.
I make 55 km with my Bulls Lacuba EVO E45. 648 Wh, and I use mostly mid-level (2 of 3) support.
My weight: 95 kg. Bike: 28 kg. Holland, so very flat surface. Temp: around 0 Celsius.

 

[EddieJ]

For my use, battery range is an impossible thing to gauge, as my terrain and riding conditions are never really the same, and my bike set up is often changing.

As examples though, the 10.4 mile long climb as shown below which covered an elevation gain of 6,428ft, required a battery change at 9.5 miles. The climb was tackled using a Bosch CX motor, and 50owh battery. I weigh 75kg and used a mix of tour with a couple of short dips into sport and turbo. https://www.strava.com/activities/658404106





Then another day I could just as easily go out and tackle a ride such a this one, which required a battery change at roughly the 45 mile point. This would have been ridden using a mix of eco and tour.




Perhaps as a yearly average, I would say the overall figure might come out 28 miles. That is purely a guess though.
At the moment, riding conditions are deep mud with forward momentum sometimes difficult, and range is down to about 18 miles using tour.

What I will say though in relation to the Bosch system when used for European off road conditions, the Performance Line motor with a 400wh battery, gives better range than a the CX motor with 500wh. That statement is based upon owning both systems and even swapping the drive unit between bikes.

I now run two CX drive units with 500wh batteries, but I do miss not having a Performance Line motor.



.

 

[Trail Cruiser]

the Performance Line motor with a 400wh battery, gives better range than a the CX motor with 500wh. That statement is based upon owning both systems and even swapping the drive unit between bikes.

I can understand how the performance line provides better range over the CX motor. The performance line is geared for speed (high cadence) and less torque. The rider tend to pedal faster and contribute more to the total output (more workout for the rider). The CX line has higher torque but the cadence support is not that high as in the performance line. The rider settles at a slightly lower cadence and the motor contributes more to the total output (less cadence equals slightly less workout for the rider).

 

[Rick Speicher]

This equation assumes you used 100% of your battery's capacity. Perhaps that is why you are getting high watt-usage numbers. You need to divide by actual battery watts used, not total capacity. Your equation is analogous to driving various distances in your car and assuming each trip used a entire gas tank.

So if you have a 598 Wh battery and finished with 20% left, then you used 80% of your battery. Therefore 598 Wh * 0.80 is 478.4 Wh used. Then divide actual watts used, 478.4, by 32 miles and you get ~15 Wh/m.

Here is a real world example. I rode my Stromer's 983Wh battery 39 miles using 85% of capacity, leaving 15% unused. So 983Wh * .85 is ~836Wh / 39 miles = 21.4 watts per mile. Terrible! But my son finished the same ride with 30% reserve on my wife's ST2 for 16.8 watts per mile. The difference? I used ludicrous mode the final 10 miles home. I was cold and hungry. He stayed in mode 2 of 3 and peddled harder. That final 10 miles using ludicrous boost made for a whopping 22% difference in total watt mileage.

This is an interesting and useful statistic. Thanks for starting the conversation.

Well, in part your absolutely right! I don't use all of my battery and I don't adjust for the small amount remaining. I have my low voltage cut of set fairly high (45v) so I don't hurt my battery, and so there is a good amount remaining when I switch to my reserve. I think though that my prodigious girth and the fact that I like to travel at about 20mph has more to do with it!

 

[Rick Speicher]

Thanks to all for your posts! I think that you have all proved what we already knew to be true, that there are a number of different factors that effect mileage, and that the same bike will produce different results based on how it is ridden! Thanks again!

 

[Trail Cruiser]

Thanks to all for your posts! I think that you have all proved what we already knew to be true, that there are a number of different factors that effect mileage, and that the same bike will produce different results based on how it is ridden! Thanks again!

Rule of thumb is you can divide the watt-hour rating of the battery by a factor of 20 to get the reliable minimum range (20 wh/mi). A 400 watt-hour battery can confidently carry you to a minimum of 20 miles, 500wh=25mi, 600wh=30mi, 700wh=35mi, and so on...

 

[Roxlimn]

I use the Giant Dirt-E 2. Yamaha mid drive + Giant components. It's still on the stock Energypak 400, which I assume has about 418 Wh of electricity, though I usually just use 400 Wh. Could be less. I usually get 80km (about 50 miles) taking the bike generally from 90% ish to 30% ish on Normal mode in rolling terrain. I've ridden it up a 634m volcano ridge on asphalt and back and still got about 80 km since the way back was almost completely downhill and used nearly no battery. Rider weight 95kg, usual cruising speed is 15 mph.

While riding, I notice that on Eco mode (lowest setting), I get about 1.8-2km per percent battery drain, so I presumably can get up to 120km range using 60% battery or thereabouts. On Normal, I get from 1.1km to 1.3 km per percent drain. On Sport, I get about 0.8-1km per percent drain. The reason Sport is so close to Normal is that it usually just accelerates you to 15 mph in a few seconds, and then it's mostly just you pedaling the bike, so the battery gets a rest. I don't see getting 32 km on 60% of the 400 Wh battery unless I was really going to abuse it. I'm expecting at least 40 km, even on Sport assuming normal use.

I got panniers and a rack so I just carry the charger with me. Charging is pretty fast - I get 20% charge in 40 minutes, so I just nip into a coffee shop for a snack and get maybe 25-30 km additional range. I've done over 100 km on the bike in a day and got home with 70+% left in the tank (recharged over lunch and coffee).