Wh/mile vs. riding range for a battery

raylo32

100 kW
Joined
Jan 4, 2019
Messages
1,084
Location
Frederick, MD USA
I am a retired engineer, not electrical, so while I am not an expert I do understand the basics and the math. One thing I am struggling with is how to determine the ultimate range I can get out of my battery that I of course know depends a lot on speed, assist, terrain, etc.

I have a bike with TSDZ2 running OSF that graphs out running Wh/mile on the display. My battery is 14s/52v, 12 Ah which equates to 625 Wh. On a recent ride I started out with a 85% soft charge to about 56.6V, rode about 35 miles and finished with an unloaded voltage of about 43V. I repeated the soft charge and my Grin reported putting in 8.1Ah which equals about 420Wh. The Wh/mile graph varied from zero to a peak of 8 and guestimating the overall average might have been ~4. So if I was really only using 4 Wh/mile that 400 Wh should have taken me 100 miles... which I know is never gonna happen. What am I missing here? Is the display under reporting Wh/mile, or what?
 
I found this info at tha internet

"recreational riders: 8-15Whr/mile
sport riders: 15-25 Whr/mile "

There is also other info at tha web

"On our folding bikes, 20 x 2.0" tires, at 132-13 mph, I burn 9-10 WH/mile while my wife uses 6 WH/mil. I'm 195 vs her 135 pounds/ I pedal continuously, while she goes on for a few seconds, off for a few seconds, so that duty cycle probably works in concert with the weight difference."

have uR own conclusions..
 
I am definitely in the sport category and I find myself having to throttle myself and/or the assist level back to keep the motor at a reasonable power and to save battery. Even in assist 2 (of 5) I can push the motor to its limits if I want to, especially on climbs, and at 185# I am also no skinny minnie. But I am certainly riding as a "recreational rider" some of the time. The Wh/Mile numbers you cite make a lot of sense. I am just tying to reconcile what I see on the display that is calculating the Wh/mile supposedly based on real time motor amps and such. It reads much lower. Might just be a quirk of the firmware... I dunno.


batteryGOLD said:
I found this info at tha internet

"recreational riders: 8-15Whr/mile
sport riders: 15-25 Whr/mile "

There is also other info at tha web

"On our folding bikes, 20 x 2.0" tires, at 132-13 mph, I burn 9-10 WH/mile while my wife uses 6 WH/mil. I'm 195 vs her 135 pounds/ I pedal continuously, while she goes on for a few seconds, off for a few seconds, so that duty cycle probably works in concert with the weight difference."

have uR own conclusions..
 
raylo32 said:
I have a bike with TSDZ2 running OSF that graphs out running Wh/mile on the display. My battery is 14s/52v, 12 Ah which equates to 625 Wh. On a recent ride I started out with a 85% soft charge to about 56.6V, rode about 35 miles and finished with an unloaded voltage of about 43V. I repeated the soft charge and my Grin reported putting in 8.1Ah which equals about 420Wh. The Wh/mile graph varied from zero to a peak of 8 and guestimating the overall average might have been ~4. So if I was really only using 4 Wh/mile that 400 Wh should have taken me 100 miles... which I know is never gonna happen. What am I missing here? Is the display under reporting Wh/mile, or what?
Something's not calibrated. Speed, current sensor, something like that.

I vary between 12 and 30 watt-hours per mile depending on how much I assist. 12 comes from just maintaining 20mph and using only PAS (no throttle.) Sounds like you are closer to 10 wh/mi, which is completely reasonable.
 
Sounds like that might be the problem but I am not sure what to check. I guess I need to dig back into this settings again and see what I can adjust... already have wheel diameter and battery voltage and capacity set. On the ride above I had to back off a lot the last 7 miles or so because I was running out of juice. Next time I do a test like that I need to start with a full battery.

The reason for my wanting to get a better handle on the range is I want to take this bike out on a club ride with my pedal bike buddies. Not to push the pace but just to do a longer fun ride. It's too hot to hammer here right now. We typically do about 50-60 miles at about 17 mph avg depending on the hill factor which is a goodly pace since we are old. I am not sure this bike will do 50 without a backup battery... although at that slow a pace it might... but then I might have to leave it in assist 1 and pedal this beast as hard as if I was on my pedal bike, which would defeat the purpose.

Something's not calibrated. Speed, current sensor, something like that.

I vary between 12 and 30 watt-hours per mile depending on how much I assist. 12 comes from just maintaining 20mph and using only PAS (no throttle.) Sounds like you are closer to 10 wh/mi, which is completely reasonable.
[/quote]
 
JackFlorey said:
I vary between 12 and 30 watt-hours per mile depending on how much I assist. 12 comes from just maintaining 20mph and using only PAS (no throttle.)

30Wh/mile is playin strong at a ebike!

I calculated now a citycoco 1500W scooter with 12,5Ah (12,5x60V=750Wh ) high drain battery ridding @40Km/h will go 30Km flat.
need to do crazy conversions to USA system.. soo 25mph will go 18miles, this means 41,7Wh per mile..

Tesla Model 3 Standard Range Plus - 253 Wh/mile(157 Wh/km) Tesla Model 3 Standard Range - 257 Wh/mile (160 Wh/km) (what speed?)

Tesla weight--> 4,323–4,960 lb (1,961–2,250 kg) + user..
Citycoco wight --> 60Kg + user
ebike weight --> 20Kg + user

no more conversions from EU to USA metric..
 
I use at least 40 Wh/mi just riding normally in city conditions. But that's with about 500 lbs GVW.
 
batterys are measured from 4.2v to 2.5v
you started at 4.04v and ended at 3.1v

my 30q-4p packs are rated at 12ah but i run them from 4.05v to 3.0v and thats 10.5ah

what cells are they

did you enter the correct resistance for the controller in the ca3
 
Good topic, I play with getting low watts per mile. Short runs can get some low numbers, the long rides are never the lowest numbers. Hills and fatigue.

It's really basics but your limited with what you ride. 15 mph is the best speed, faster your just pushing air. leave the throttle alone, watt sucker. Get more watts from a battery if the amps are kept low. peddle more at first use more assist later. air tires up to max, road tires are better, few miles per ride. brakes waste watts.

I do a 50 mile ride on a trail system if I follow the rules 500w per 50miles if not it's more like 1000w. The trail system is twists and turns and small hills never get above 15mph. Do out of town rides but it's more about a balance of speed and distance. 20-30mph last ride was 58 miles and used 1200w. If you notice I could get my watts per mile lower on the hwy than the trail system. Don't use brakes on the hwy.

Trike and I are 350lbs, recover about 5-10% of watts used thru regen.
 
I don't have time to do standard formalized tests of this but I rode my CYC bike yesterday... about 25-30 miles (forgot to reset the trip odo and didn't have my Garmin) and it seemed to be more efficient than the TSDZ2. Only used about 5 amp hours as indicated on the Grin after charging. Heading out today for a longer hiller ride...
 
Just did another ride on my CYC bike, almost entirely on assist level 2 (out of 9) with a few miles of level 1 and a few miles of level 3. On these sorts of rides on my road bike I typically average about 180 human watts input and I believe I did about the same on this ride. IOW, no loafing just because I am on an e-bike.

Started with a fully charged 12 Ah 52v battery, charge terminated automatically on the Grin to 58.8v. I took the Garmin today and it reported that the ride was 33.5 miles, 2450 vertical feet of climbing, 18.0 mph average. No load battery voltage at the end of the ride was 49.3v. I am not sure how that 49.3v equates to the final SOC... I need to look into that... and use that to extrapolate how much farther I could go under similar assumptions. Or how much faster I could go by running more assist on a ride of this length! This bike is a fully suspended Specialized Stumper, weighs about 45 pounds with motor and battery, and is running 2.3" tubeless MTB knobbies @28psi. I suppose to get max road ride range I could swap those tires for some thinner and higher pressure commuting or gravel type tires.
 
raylo32 said:
OK... I gotta ask... are you delivering refrigerators?? ;)

Chalo said:
I use at least 40 Wh/mi just riding normally in city conditions. But that's with about 500 lbs GVW.

No, not yet anyway. Lately I weigh about 375 pounds (at 6'8"), and my cargo bike weighs close to 100 pounds with the battery mounted (X5305 motor is over 22 lbs, battery is about 26 lbs in its bag). I'm almost always carrying something or another in the cargo box.

My other e-bike isn't quite as heavy, but it goes a bit faster, and that uses more juice.

Markz is in the same general weight class and runs similar powered hub motors. I wonder what his average Wh/mi consumption is?
 
Wow... and I thought I was a big guy for a cyclist... at least for a semi serious pedal cyclist... at 185! You guys stress testing the equipment and motors has got to make it get better and stronger over time.


No, not yet anyway. Lately I weigh about 375 pounds (at 6'8"), and my cargo bike weighs close to 100 pounds with the battery mounted (X5305 motor is over 22 lbs, battery is about 26 lbs in its bag). I'm almost always carrying something or another in the cargo box.

My other e-bike isn't quite as heavy, but it goes a bit faster, and that uses more juice.

Markz is in the same general weight class and runs similar powered hub motors. I wonder what his average Wh/mi consumption is?
[/quote]
 
All I can say is I get about ~25km on a 52V 14.5Ah (750wh) new'ish battery on a 36-48V 35A Greentime controller. 30wh/km

I use 2 batteries on my bike, the second is an old 36V with unknown Ah that I figure now has 500wh based on 22km range.

I can tell you that I do get 55km on both batteries.

328lbs 6'6"
1x7, fat bike cruiser with 26x4 rear tire, 26x2.25 front tire hub, both smooth tread, back pack 10-20lbs, casual cruising speeds ~32kph, few steep hills.
 
Here's another data point:

I have a 1500W leaf motor rear hub motor on a 26" mountain bike. Total weight of me + bike is probably around 300lbs. When I keep it to ~20mph top speed I would say I average just shy of 25wh/mi in the city. I use a throttle, but usually pedal when accelerating from dead stops and when going uphill. This is of course an estimate, its based on the read out on my Nucular controller.
 
were not serious pedal cyclist, just e-bikers. So now you know the bigger guys have bigger batteries. My battery was 1800w when new.

I would not change your bike all around just get more battery.
 
raylo32 said:
I am a retired engineer, not electrical, so while I am not an expert I do understand the basics and the math.

What am I missing here? Is the display under reporting Wh/mile, or what?

I seem to remember reading in one of the giant TDSZ2 thread about some versions of the OSF and displaying in imperial units and some potential problems.

It might be worth trying a ride with the display set to show in metric units as a test.

If it said you were doing roughly 4 Wh/mile, it should show 2.5 Wh/km for the same ride (1 mile is approx 1.6km). If the average seems to be higher than 4 then the problem is in the display firmware not correctly converting to miles in the Wh/miles calculation, knowing that the OSF natively uses metric. If for example the Wh value gets divided by the 1.6 conversion factor instead of multiplied as it should be, then if the calculation was correct it would have shown something averaging just over 10Wh/mile for your ride (4 x 1.6 x 1.6) - which is not too far removed from 35 miles using about 400Wh, certainly not for an estimated average from a smallish graph.

I wish I could remember which thread had the discussion. Depending on what version you have it might have been resolved - assuming that is the problem.
 
Just some thoughts. If you are getting under 20w/m on an upright bike that is good. 10w/m is in the recumbent area.

As far as batteries, I might charge mine to 90-100% just before the ride and never plan on using all the battery. 750w battery I would never use more than 5-600w. I would try not to go below 46-47v or use more then 70-80%. I plan to use my batteries for +5y's. Smaller batteries can be replaced more often.

I ride a trike and look just over my toes while riding so don't compare yourself to me. Don't get to hung up on weight, which matters taking off and climbing hills. Going down the heaver the faster. Road riding it's about pushing the wind and rolling resistance.

If you want to get into the low watt per mile get a bike that can do it. upright big soft tire bike needs power.
 
I am a serious road pedal biker so I understand all too well what it takes to go fast efficiently. Aerodynamics, rolling resistance, etc. ​Yup, pushing air is the biggest problem, but here also we have long tough hills where weight comes into play. I am not so much interested in simply maximizing wh/mile as just seeing if it would be possible to do some of our group rides on one of my e-bikes with one battery. With these rides being in the 50-60 mile range that is looking unlikely. Now I may be able to pull it off on my TSDZ2 bike with the 12Ah shark battery supplemented with one of my EGO 5 Ah tool batteries on the rack mounted socket I made. It also has 26" wheels but narrower and harder tires than my CYC MTB. I do these rides on human power alone on my 18 pound road bike so I suppose I would need just enough battery to make the 50 pound bike feel like the 18 pound bike. Well, more really since the 18 pound bike also has a more aero riding position and much lower rolling resistance. But really I want the motor to do more to make it easier still or why even take the e-bike?

46-47V sounds like a prudent cutoff.


ZeroEm said:
Just some thoughts. If you are getting under 20w/m on an upright bike that is good. 10w/m is in the recumbent area.

As far as batteries, I might charge mine to 90-100% just before the ride and never plan on using all the battery. 750w battery I would never use more than 5-600w. I would try not to go below 46-47v or use more then 70-80%. I plan to use my batteries for +5y's. Smaller batteries can be replaced more often.

I ride a trike and look just over my toes while riding so don't compare yourself to me. Don't get to hung up on weight, which matters taking off and climbing hills. Going down the heaver the faster. Road riding it's about pushing the wind and rolling resistance.

If you want to get into the low watt per mile get a bike that can do it. upright big soft tire bike needs power.
 
by raylo32 » Jul 15 2021 10:05am

I am a serious road pedal biker so I understand all too well what it takes to go fast efficiently. Aerodynamics, rolling resistance, etc. ​Yup, pushing air is the biggest problem, but here also we have long tough hills where weight comes into play. I am not so much interested in simply maximizing wh/mile as just seeing if it would be possible to do some of our group rides on one of my e-bikes with one battery. With these rides being in the 50-60 mile range that is looking unlikely. Now I may be able to pull it off on my TSDZ2 bike with the 12Ah shark battery supplemented with one of my EGO 5 Ah tool batteries on the rack mounted socket I made. It also has 26" wheels but narrower and harder tires than my CYC MTB. I do these rides on human power alone on my 18 pound road bike so I suppose I would need just enough battery to make the 50 pound bike feel like the 18 pound bike. Well, more really since the 18 pound bike also has a more aero riding position and much lower rolling resistance. But really I want the motor to do more to make it easier still or why even take the e-bike?

I figured you did!
I ride for my health and unable to push hard to pull hills. So the e-trike takes the strain away and lets me do long rides that I could not do with out it. There is just no magic. Let us know when you do the ride.
 
Chalo said:
raylo32 said:
OK... I gotta ask... are you delivering refrigerators?? ;)

Chalo said:
I use at least 40 Wh/mi just riding normally in city conditions. But that's with about 500 lbs GVW.

No, not yet anyway. Lately I weigh about 375 pounds (at 6'8"), and my cargo bike weighs close to 100 pounds with the battery mounted (X5305 motor is over 22 lbs, battery is about 26 lbs in its bag). I'm almost always carrying something or another in the cargo box.

My other e-bike isn't quite as heavy, but it goes a bit faster, and that uses more juice.

Markz is in the same general weight class and runs similar powered hub motors. I wonder what his average Wh/mi consumption is?
He ia a refrigerator ... or about the same size. :lol:
There used to be a professional football player that they called "The Refrigerator"
William Anthony Perry https://en.wikipedia.org/wiki/William_Perry_(American_football)

So to add a bit of light at the other end of the spectrum:
I am about about 135 pounds arranged over an old, worn out, six foot tall skeleton.
I contribute very little energy to the process of getting from point "A" to point "B".
As I live in Houston, there is nothing any reasonable person might call a hill.
On a recent trip to the grocery store I recorded the following:

Top speed = 20 miles per hour
Distance to grocery store = 2.4 miles one way
There are seven "complete stops" either direction.
To store = 57 watt hours used = 23.8 watt hours per mile
From store = 67 watt hours = 27.9 watt hours per mile
Ambient Temperature = 85 degrees
Motor Temperature = 94 degrees
Controller Temperature = 101 degrees

The trip back had an about 40 pounds of groceries in the Burley Travoy Trailer.
The energy readings were taken using an in-line Drock power meter (nominal 36 volt LiFePO4 battery).
The bike was the "Weight Weenie" (see below) recently upgrade to a ebikeLing 500 watt front geared hub.
 
LOL!! Looks like you have a great setup for a grocery go getter. Alls I have is a backpack.

LewTwo said:
He is a refrigerator ... or about the same size. :lol:
There used to be a professional football player that they called "The Refrigerator"
William Anthony Perry https://en.wikipedia.org/wiki/William_Perry_(American_football)

So to add a bit of light at the other end of the spectrum:
I am about about 135 pounds arranged over an old, worn out, six foot tall skeleton.
I contribute very little energy to the process of getting from point "A" to point "B".
As I live in Houston, there is nothing any reasonable person might call a hill.
On a recent trip to the grocery store I recorded the following:

Top speed = 20 miles per hour
Distance to grocery store = 2.4 miles one way
There are seven "complete stops" either direction.
To store = 57 watt hours used = 23.8 watt hours per mile
From store = 67 watt hours = 27.9 watt hours per mile
Ambient Temperature = 85 degrees
Motor Temperature = 94 degrees
Controller Temperature = 101 degrees

The trip back had an about 40 pounds of groceries in the Burley Travoy Trailer.
The energy readings were taken using an in-line Drock power meter (nominal 36 volt LiFePO4 battery).
The bike was the "Weight Weenie" (see below) recently upgrade to a ebikeLing 500 watt front geared hub.
 
I can still push pretty hard on hills but not like when I was younger. Just keep losing more top end VO2 with age. As you note the big difference is humping over the tough hills. In the past it was much easier and I had reserves left... now closer and closer to the margins, if not hitting the wall altogether on faster climbs. The e-bike is like magic to ease the load just enough to make it more fun... or totally if I get really gassed in this ungodly heat. These things are fun.

ZeroEm said:
I figured you did!
I ride for my health and unable to push hard to pull hills. So the e-trike takes the strain away and lets me do long rides that I could not do with out it. There is just no magic. Let us know when you do the ride.
 
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