Battery range, understanding the “tuning” parameters.

[Ngnear]

I have a Creo and the motor is rated for a maximum output of 240 watts, while the battery is rated at approximately 330 watt-hours. I was trying to make sense of the tuning parameters (Eco/Sport/Turbo and the associated values) as described within the Specialized literature and how the various settings impact range (miles) on the bike. There are two values for each setting, Support and Peak. Specialized described how these “work”, but it just wasn’t making perfect sense. The Peak setting is easiest for me to understand, it is the most power produced by the motor and is found by multiplying the setting value by the maximum output rating of the motor. In the case of Eco with the default setting of “35”, 240w times 0.35 = 84 watts. When on the 35%setting, the motor has a ceiling output of 84 watts. However, to get the motor to put out the maximum 84 watts, you (the person) must pedal and generate 240 watts. If the person generates 240 watts, then the motor adds and additional 84 watts for a total power of 324 watts. If a person generates more than 240 watts, the motor is capped at 84watts (in the Eco setting of 35). The Support value is a bit more confusing, but this is how I interpreted it to work. If the person generates 100 watts of power, and the support setting is 35 (again the default setting for Eco), the motor provides 35 watts of power (100w times 0.35). This provides a total power of 135 watts. Here is a table for the default 35/35 Eco Setting:

Power Meter (legs) Motor Power (machine) Total Power
100w 35w 135w
150 52.5 202.5
200 70 270
240 84 (max) 324
300 84 384

I am assuming the Power value that is being shown on my Garmin head unit data field is the power being generated by me and does NOT include the additional power from the motor.

Getting to the range issue. The battery is rated at approximately 330 watt hours. With a peak output of 84 watts at the Eco setting of 35, second value in the 35/35 setting), the battery would last 330/84=3.9 hours. This assumes a full charge with a linear discharge, and the person generates at least 240watts on their own. If all of this is correct, the question is how far can I go? That depends on the average speed over that 3.9 hours. If the average speed is 20 mph, then the range would be 78 miles. If the power is held constant, the speed would vary due to headwind, gradient, etc.

With the maximum output limited to 35%, you should be able to get nearly 4 hours of riding. Does this make sense? Sorry for the long and maybe confusing post, just trying to make sense of the tuning settings and how they impact range.

 

[landonphd]

I have a Creo and the motor is rated for a maximum output of 240 watts, while the battery is rated at approximately 330 watt-hours. I was trying to make sense of the tuning parameters (Eco/Sport/Turbo and the associated values) as described within the Specialized literature and how the various settings impact range (miles) on the bike. There are two values for each setting, Support and Peak. Specialized described how these “work”, but it just wasn’t making perfect sense. The Peak setting is easiest for me to understand, it is the most power produced by the motor and is found by multiplying the setting value by the maximum output rating of the motor. In the case of Eco with the default setting of “35”, 240w times 0.35 = 84 watts. When on the 35%setting, the motor has a ceiling output of 84 watts. However, to get the motor to put out the maximum 84 watts, you (the person) must pedal and generate 240 watts. If the person generates 240 watts, then the motor adds and additional 84 watts for a total power of 324 watts. If a person generates more than 240 watts, the motor is capped at 84watts (in the Eco setting of 35). The Support value is a bit more confusing, but this is how I interpreted it to work. If the person generates 100 watts of power, and the support setting is 35 (again the default setting for Eco), the motor provides 35 watts of power (100w times 0.35). This provides a total power of 135 watts. Here is a table for the default 35/35 Eco Setting:

Power Meter (legs) Motor Power (machine) Total Power
100w 35w 135w
150 52.5 202.5
200 70 270
240 84 (max) 324
300 84 384

I am assuming the Power value that is being shown on my Garmin head unit data field is the power being generated by me and does NOT include the additional power from the motor.

Getting to the range issue. The battery is rated at approximately 330 watt hours. With a peak output of 84 watts at the Eco setting of 35, second value in the 35/35 setting), the battery would last 330/84=3.9 hours. This assumes a full charge with a linear discharge, and the person generates at least 240watts on their own. If all of this is correct, the question is how far can I go? That depends on the average speed over that 3.9 hours. If the average speed is 20 mph, then the range would be 78 miles. If the power is held constant, the speed would vary due to headwind, gradient, etc.

With the maximum output limited to 35%, you should be able to get nearly 4 hours of riding. Does this make sense? Sorry for the long and maybe confusing post, just trying to make sense of the tuning settings and how they impact range.

Been wondering about this and other similar things. Thanks for making this post.

 

[Stefan Mikes]

If the person generates 100 watts of power, and the support setting is 35 (again the default setting for Eco), the motor provides 35 watts of power (100w times 0.35). This provides a total power of 135 watts

Not.
The SL Boost Factor is 1.8x (mechanical).

Input 100 W at 100% Support and the motor will respond with 180 W. At 50% Support, the response will be 90 W (mechanical).

Your interpretation of Peak is correct. Whenever the power output = rider's input * current Boost shall be greater than the defined Peak, the motor output power will stay at Peak.

Besides, the SL battery is 320 Wh. Now, you can calculate the ride time. And... Hills are a significant game changer as you and the motor have to input work to gain the potential energy.

 

[Ngnear]

Not.
The SL Boost Factor is 1.8x (mechanical).

Input 100 W at 100% Support and the motor will respond with 180 W. At 50% Support, the response will be 90 W (mechanical).

Your interpretation of Peak is correct. Whenever the power output = rider's input * current Boost shall be greater than the defined Peak, the motor output power will stay at Peak.

Besides, the SL battery is 320 Wh. Now, you can calculate the ride time. And... Hills are a significant game changer as you and the motor have to input work to gain the potential energy.

Thanks Stefan, I didn’t realize the support value was discounted from the full value. That makes more sense with my real experiences in battery range. I feel I can achieve a longer trip than 78 miles on the 35% Eco setting and the discounted factor will push it further than the 78 miles. Besides, I also do not believe I average 240 watts myself for the entire 4+ hours, thus stretching the battery even further. I would think the motor would be at the maximum the entire time on the hills (longer steeper hills) and the battery drain wouldn’t be any greater than if the rider pushes the bike beyond 240 watts on the flats, the battery still peaks at the maximum output. I just assume you would go slower up the hill than on the flat. Anyway, great conversation, much appreciated!

 

[mschwett]

Thanks Stefan, I didn’t realize the support value was discounted from the full value. That makes more sense with my real experiences in battery range. I feel I can achieve a longer trip than 78 miles on the 35% Eco setting and the discounted factor will push it further than the 78 miles. Besides, I also do not believe I average 240 watts myself for the entire 4+ hours, thus stretching the battery even further. I would think the motor would be at the maximum the entire time on the hills (longer steeper hills) and the battery drain wouldn’t be any greater than if the rider pushes the bike beyond 240 watts on the flats, the battery still peaks at the maximum output. I just assume you would go slower up the hill than on the flat. Anyway, great conversation, much appreciated!

That’s in fact the exact reason for the “max” output parameter - if it were solely a scaled factor of your power, the harder you pedaled the LESS range you’d get, as the motor output increased and the physics of drag exponentially increased the power required of you and the motor to go each extra MPH.

as Stefan pointed out, at 100% support factor it takes a human input of around 130-150w to get 240w of motor power, which corresponds to a 300w battery draw. beware that the 1.8x or 2.0x referred to by specialized are not exact - my experiments show that they tend towards providing more power rather than less, so leave yourself a little cushion in the math.

you may be an incredibly strong cyclist, but 240w for 4 hours is A LOT - that’s competitive racing territory for an average sized human.

 

[Ngnear]

That’s in fact the exact reason for the “max” output parameter - if it were solely a scaled factor of your power, the harder you pedaled the LESS range you’d get, as the motor output increased and the physics of drag exponentially increased the power required of you and the motor to go each extra MPH.

as Stefan pointed out, at 100% support factor it takes a human input of around 130-150w to get 240w of motor power, which corresponds to a 300w battery draw. beware that the 1.8x or 2.0x referred to by specialized are not exact - my experiments show that they tend towards providing more power rather than less, so leave yourself a little cushion in the math.

you may be an incredibly strong cyclist, but 240w for 4 hours is A LOT - that’s competitive racing territory for an average sized human.

Totally agree, I didn’t mean to suggest I produce 240watts over such a long ride. On a good ride, 2 hours long, I may average 180 watts, but most times around 160-170.

 

[Stefan Mikes]

as Stefan pointed out, at 100% support factor it takes a human input of around 130-150w to get 240w of motor power, which corresponds to a 300w battery draw. beware that the 1.8x or 2.0x referred to by specialized are not exact - my experiments show that they tend towards providing more power rather than less, so leave yourself a little cushion in the math.

Let me explain the confusion there. It is because of the difference between mechanical output power (1.8x) and electrical motor power (2x), the latter translating to the battery draw. The SL 1.1 motor efficiency is roughly 80%. When the motor delivers the mechanical output of 240 W, it also draws as much as 304 W from the battery (and the latter value is easy to document).

On a good ride, 2 hours long, I may average 180 watts, but most times around 160-170.

As you @Ngnear say your legs are strong, you should dramatically reduce the Peak for your lower assistance modes, that is, Eco and Sport. That will put the cap on the battery draw. Let me give an example:

The usable battery charge is 95% of 320 Wh, or 304 Wh. As we know the approximate maximum electrical power of the motor is 304 W, riding at the full motor power allows just an hour of riding. But you need to ride assisted for 4 hours. Just use the Peak % of 25% and your first chore is done.

What to do with the Assist %? Let us find the setting with makes your motor work at the Peak with your 180 W leg input. The available battery power draw will be 304 Wh / 4 hours = 76 W. The motor output will be 76 * 0.8 (motor efficiency) = 60.8 W. Assist % = 60.8 W / 180 W / 1.8 = 18.7%. Meaning, the 20% of Assist will keep your motor saturated at 25% Peak with your leg input of 180 W.

The proper setting:
Assist % = 20
Peak % = 25.

If you reduce the assist to 15%, expect even longer ride but with yet less support.

@mschwett: Am I correct?

 

[mschwett]

Let me explain the confusion there. It is because of the difference between mechanical output power (1.8x) and electrical motor power (2x), the latter translating to the battery draw. The SL 1.1 motor efficiency is roughly 80%. When the motor delivers the mechanical output of 240 W, it also draws as much as 304 W from the battery (and the latter value is easy to document).

...

yes, but 1.8 is 90% of 2.0 ... and although the motor may be a bit better than 80% it's not 90%! as i said, not exact. the difference between the 1.8 and 2.0 figures referenced in various times and places is not entirely clear. completely agreed on the 300w battery draw, which probably corresponds to 230-250w of mechanical power. the question is whether the assist algorithms are looking for 130w of leg power (240/1.8) or 150w (300/2) or 120w (240/2) or ...

add to that the power "meter" being off by 5-10% and it's definitely not an exact science, other than the 300w part!

 

[Stefan Mikes]

yes, but 1.8 is 90% of 2.0 ... and although the motor may be a bit better than 80% it's not 90%! as i said, not exact. the difference between the 1.8 and 2.0 figures referenced in various times and places is not entirely clear. completely agreed on the 300w battery draw, which probably corresponds to 230-250w of mechanical power. the question is whether the assist algorithms are looking for 130w of leg power (240/1.8) or 150w (300/2) or 120w (240/2) or ...

add to that the power "meter" being off by 5-10% and it's definitely not an exact science, other than the 300w part!

Mark,
Let us leave the marketing crap of "It's 2x you!" behind, will we?

I absolutely trust Specialized about 240 W max motor power. They could brag it was more. No, they stay with the 240 W which is less than the EU nominal limit of 250 W. You know the 300 W figure by heart. The efficiency such as 79% is reasonable. So basically, we both understand the technology and figures very well.

You seem to be an engineer to me?

 

[mschwett]

Mark,
Let us leave the marketing crap of "It's 2x you!" behind, will we?

I absolutely trust Specialized about 240 W max motor power. They could brag it was more. No, they stay with the 240 W which is less than the EU nominal limit of 250 W. You know the 300 W figure by heart. The efficiency such as 79% is reasonable. So basically, we both understand the technology and figures very well.

You seem to be an engineer to me?

welll... stefan, i won't debate this any further beyond this post, i will simply state that 1) specialized still calls it "2x you," 2) it is referred to in many, many places as "2x you" beyond specialized's website etc, and 3) the data from my creo sl, at least, clearly shows that it's 2x or more, not 1.8x. if i compare the rider input and motor power input from my rides, adjusted to reflect 80% motor efficiency shows that the assist factor is 2.0, or even higher, not 1.8. in other words, at 100/100, on my creo, it only takes 120w of rider power to get the motor to draw 300w from the battery, resulting in 240w of mechanical power from the motor. at 50/100, 240w of rider power causes a 300w battery draw and 240w of mechanical power. the data does not lie.

the fat gold line is [motor draw x .8]/[rider power.] you see that it is in all cases more than twice the mission control assist setting. 2x. not 1.8x. and that is all i have to say on the subject!

 

[Stefan Mikes]

2x. not 1.8x. and that is all i have to say on the subject!

I cannot deny the outcome of your careful experiments Mark, so let it be 2x from now on!

 

[Stefan Mikes]

2x. not 1.8x. and that is all i have to say on the subject!

I have found something interesting for you

The Specialized description of the 1.2s motor used in my big Vado...

All good, only the Type Approval document for that e-bike clearly states the amplification factor is 3.2x... (Did I say anything about the marketing?) You cannot tell lies in the Type Approval paper: it is serious.

And now, the best of all:

SL Motor

support.specialized.com

Even the Protection Rating is mismatched here...

 

[Richard Stallard]

I don’t disagree with the figures, but with the (mis)use of words like amplification and factor.

The way of measuring amplification is to divide the output by the input, and this is the “amplification factor”.

If the SL motor contributes 1.8x rider input power, then the amplification factor is 2.8 because the output power is the sum of rider power plus motor (mechanical) power.

The above corresponds with basic mathematics, in which a factor is something that is used to multiply something else to get a result. So, if the result is the original + [1.8x the original] then the multiplication factor is 2.8.

I agree that the terminology used by Specialised is confusing and somewhat surprising as 2.8x sounds more impressive from a marketing viewpoint compared to 1.8x or 2x.

 

[mschwett]

I have found something interesting for you

The Specialized description of the 1.2s motor used in my big Vado...

All good, only the Type Approval document for that e-bike clearly states the amplification factor is 3.2x... (Did I say anything about the marketing?) You cannot tell lies in the Type Approval paper: it is serious.

And now, the best of all:

SL Motor

support.specialized.com

View attachment 132456
Even the Protection Rating is mismatched here...

lol, that’s really funny - 180% = 2x

add to it the fact that the measurement of rider power isn’t actually all that accurate compared to a strain based power meter and the whole thing is quite fuzzy. however, i will say … it works extremely well. immediate assist from a stop but extremely smooth and natural feeling!

 

[mschwett]

I don’t disagree with the figures, but with the (mis)use of words like amplification and factor.

The way of measuring amplification is to divide the output by the input, and this is the “amplification factor”.

If the SL motor contributes 1.8x rider input power, then the amplification factor is 2.8 because the output power is the sum of rider power plus motor (mechanical) power.

The above corresponds with basic mathematics, in which a factor is something that is used to multiply something else to get a result. So, if the result is the original + [1.8x the original] then the multiplication factor is 2.8.

I agree that the terminology used by Specialised is confusing and somewhat surprising as 2.8x sounds more impressive from a marketing viewpoint compared to 1.8x or 2x.

yes, i totally agree. to your point but also the silent omission of the motor multiplication factor in the apps “support factor.” i understand why they’ve done it, so all the bikes of various power levels have a 0-100 scale, but it leads people to believe much less power is available or being used than really is.

but again… from the riding standpoint, it works exceptionally well.

 

[Stefan Mikes]

I don’t disagree with the figures, but with the (mis)use of words like amplification and factor.

The way of measuring amplification is to divide the output by the input, and this is the “amplification factor”.

If the SL motor contributes 1.8x rider input power, then the amplification factor is 2.8 because the output power is the sum of rider power plus motor (mechanical) power.

The above corresponds with basic mathematics, in which a factor is something that is used to multiply something else to get a result. So, if the result is the original + [1.8x the original] then the multiplication factor is 2.8.

I agree that the terminology used by Specialised is confusing and somewhat surprising as 2.8x sounds more impressive from a marketing viewpoint compared to 1.8x or 2x.

Guys,
The matter is not as simple as you might think. I could read a paper (long time ago) about the e-bike "assistance factor"; it looks like an established industry standard. At some time, politicians and manufacturers agreed that the "maximum assistance factor" shall not exceed 4.0. I'm sure the definition was put into the European automotive law discussing "L" classes.

I keep the EU Certificate of Conformity for my 45 km/h Vado 5.0. Note the "maximum assistance factor" is written there, meaning, it is a mandatory and legally necessary value.

Interestingly, the latest 2.1 motor used on Levo achieves the factor of 4.1, which just means that the agreed industry value of 4.0 was just a recommendation.

 

[Ngnear]

You guys are truly experts and I find this conversation very educational and downright interesting, I have learned a ton! I have had my Creo for a little less than one year and can’t tell you how much I enjoy riding it! Since I am relatively new to the Ebike, I was naturally curious about the range with the given main battery and then with the added Range Extender. You all have provided the insight to make some excellent choices on tuning the bike in Eco/Sport/Turbo modes to maximize the battery(s) to the condition (ride). I just finished my longest ride on this bike a few moments ago. At 101 miles, my battery % was down to 45% (that’s the Main and the RE). The climbing was about 2,800’ and my average speed was 17 mph and I was in Eco (35/35) for the first 101 miles. I actually finished with a little over 105 miles as I used the Turbo mode for the last 4 miles home. The last 4 miles was relatively flat and I was ready to get home. The range is what I expected based on all the information you provided. Thanks again!

 

[Richard Stallard]

Guys,
The matter is not as simple as you might think. I could read a paper (long time ago) about the e-bike "assistance factor"; it looks like an established industry standard. At some time, politicians and manufacturers agreed that the "maximum assistance factor" shall not exceed 4.0. I'm sure the definition was put into the European automotive law discussing "L" classes.

I keep the EU Certificate of Conformity for my 45 km/h Vado 5.0. Note the "maximum assistance factor" is written there, meaning, it is a mandatory and legally necessary value.

View attachment 132480

Interestingly, the latest 2.1 motor used on Levo achieves the factor of 4.1, which just means that the agreed industry value of 4.0 was just a recommendation.

I don’t have a problem with “assistance factor”. That is different from amplification.

Amplification = output/input = (rider power + assistance power) / rider power.

As documented in Wikipedia (https://en.wikipedia.org/wiki/Electric_bicycle_laws#European_Union_definition) the EU rules for pedal assist bikes are much simpler, based only on power output and speed. The ”SL” bike fall under the simpler rules.

The rules which Stefan is referring to only apply to the higher power/speed bikes which are classed as mopeds and therefore fall under motor vehicle design rules.

 

[Stefan Mikes]

Amplification = output/input = (rider power + assistance power) / rider power.

For the industry the amplification factor = motor output power / rider's input power.

The rules which Stefan is referring to only apply to the higher power/speed bikes which are classed as mopeds and therefore fall under motor vehicle design rules.

It is never referenced for the "regular" e-bike legal definition but is often used by manufacturers for marketing purposes. Like, Giant/Yamaha PW-X2 motor of the amplification factor of 360% or Bosch CX with its 380%. It is, for instance, possible to tune the amplification factor of a Giant e-bike by selecting Amplification Factor % directly from 11 preset values spread over 5 assist levels. However, no e-bike I know (except Specialized) offers the capability to set the Peak Power. Therefore, Giant e-bikes always seem to be overpowered and battery hungry.

 

[Stefan Mikes]

105 miles

What a feat! You are in the @mschwett's performance region if we talk about Creo riders here