Specs and Upgradeability

[Scott]

This is a very helpful forum and thanks to all for the responses to my earlier question. I was really close to making a decision to purchase a BH Easy Motion for me, my wife and son but I started focusing more carefully on the specs. I was looking at the Easy Motion (Carbon, Jumper, City), Volton (Alation 500), Pedego (Interceptor/City Commuter) and Motiv (Spark). All use Lithium Ion batteries. Volton uses a Lithium Polymer, but my research indicates that it is not a significant difference. The battery configurations are different, however.

• Pedego City Commuter; 48V 10ah = 480 watt hour = roughly 15 miles
• Volton Alation 500; 36V 11ah = 396 watt hour = roughly 13-14 miles
• Volton Alation 500; 48V 11ah = 528 watt hour = roughly 17 miles
• Motiv Spark; 48V 10ah = 480 watt hour = 15 miles
• Motiv Spark; 36V 15ah = 540 watt hour = roughly 17-18 miles
• Neo Jumper/Carbon; 36V 9ah = 324 watt hour = roughly 11-12 miles

Now, each of these manufacturers advertise varying distances, all of which are more than the mileage noted above, which came from here http://www.electricbike.com/lithium-battery/ If you pedal, you'll of course get more distance, but I'm just trying to determine what you'll get if you don't pedal, for comparative purposes (I'm sure Court and Ravi will pedal much more vigorously than me given my age and cardio).

The other thing is that each of these bike manufacturers has a 500 watt motor, except Easy Motion. Easy Motion only has a 350Watt motor. Therefore, I am concerned that the Easy Motion will not give me the battery output the other bikes will so I am now leaning toward one of the other three. I guess the other question is upgradeability. If you buy any of these bikes and the manufacturer upgrades the battery in a newer model (more volts or more amps or both), can I upgrade the battery without upgrading the bike? Will it depend on the size of the bike motor? In other words, is the Easy Motion necessarily limited in terms of upgradeability because it only has a 350Watt motor?

 

[Admin]

Hi Scott! Thank you for producing the specs for comparison here and articulating your point so well. In essence, watt hours are how many "watts" you will use up in one "hour" when riding at full speed. So if you have a 350 watt motor and a 350 watt hour batter pack then you could ride for exactly one hour (at full speed but in optimal conditions) before the battery would be completely tapped out. So the one thing missing from your list is motor size (and indeed you call it out in your comments). Let me just add motor size below and let's assume that top speed for each bike is 20mph even though some of the 2013 Neo bikes can reach ~27 in pedal assist mode...

• Pedego City Commuter 48V, 10ah: 500 watt motor, 480 watt hour battery = 480/500*20 = 19.2 miles
• Volton Alation 500 36V, 11ah: 500 watt motor, 396 watt hour battery = 396/500*20 = 15.8 miles
• Volton Alation 500 48V, 11ah: 500 watt motor, 528 watt hour battery = 528/500*20 = 21.1 miles
• Motiv Spark 48V, 10ah: 500 watt motor, 480 watt hour battery = 480/500*20 = 19.2
• Motiv Spark 36V, 15ah: 500 watt motor, 540 watt hour battery = 540/500*20 = 21.6 miles
• Neo Jumper/Carbon 36V, 9ah: 350 watt motor, 324 watt hour battery = 324/350*20 = 18.5 miles

The reason that estimates from electricbike.com and some other critical sources may be lower is due to the bob of suspension, girth and tread of tires, wind, rider variability and other environmental factors along with the imperfections of each battery pack... that will continue to degrade over time as electrons are lost. One of the biggest factors in extending battery life is keeping them from getting too hot (this is why laptops seem to die early, because they heat up as they are used and charging at the same time... being plugged in).

Now here's the kicker, if you weigh a lot and are straining the motor and battery pack in your ebike, you're going to discharge and degrade the battery more quickly because it will be heating up. Also, keep in mind these distance specs that I've computed above are at "full power" and most people don't ride like that so ebike companies take some liberty when quoting distance specs on their websites. So, with all of this in mind, if you weigh over 180lbs, I'd recommend going with a 48 volt battery vs. a 36 volt version... even though the math says the 36 volt 15 amp hour version will go further (on the Spark for example). It will actually probably go close to the same distance but struggle more to get there and be less satisfying. All of this gets even more complex when you throw in pedal assist, higher top speeds and the mechanical makeup of each bike (wheel size, tire size and tread, suspension lockout etc.) everything matters.

So the way I position my reviews and advice on the site is qualitative because hopefully it reflects the real world ambiguity of this technology. We haven't even talked about battery chemistry yet but that also matters. For example, Lithium Iron Phosphate is known for having good throughput which means it can charge and discharge quickly but it also tends to heat up more. By comparison, Lithium Cobalt is more steady but has lower throughput and thus is used almost exclusively now in laptops, phones and many of the top ebikes. Lithium polymer has a lower energy density and lacks some of the longevity (number of battery cycles before fading) that these other Lithium chemistries offer.

So all of this said, I like the Neo bikes (even with their smaller motors) because they have a seamless drive system that is light weight and high quality. They do offer replacement battery packs (all of their bikes use the same exact battery configuration) and they are even offering a 12 amp hour pack on their new 650B cross country ebike. It's not a bike that is limited in terms of upgradability when talking about batteries but you will always be stuck with the motor you get with the bike, that's much harder to upgrade. Another big consideration here is maintenance since most people ride ebikes faster, harder and more often than regular bikes. I tend to lean towards buying an ebike from a company I trust or that has a dealer nearby. This strategy just came in very handy for James who bought a Stromer from a local dealer who saved the day when his charger broke.

With Motive and Volton you will save money on the initial purchase, get excellent support and have the option of getting a strong 500 watt geared motor with 48 volt pack that will work great if you're a heavier rider. I do question the Lithium Polymer chemistry that Volton is using (and I know they have also used Lithium Iron Phosphate) but my experience has still been really good with their bikes. With Pedego you'll get the same strong 500 watt geared motor and 48 volt pack option but pay more doing it. The upside here is that depending on where you live, you'll end up with a dealer that can help you with any support issues, maintenance and repairs on a regular basis. I already called out Easy Motion and even though they seem like the under dog here with a smaller motor and battery, if you want a more agile bike these things are certainly capable.

Please let me know your thoughts on all of this, I can't claim to be an expert as I have never manufactured an ebike but this information is accurate to the best of my knowledge and I'll ask a few of the other guys to chime in on the discussion.

 

[Scott]

You are the Master Yoda of E-bikes! Very knowledgeable, you are. ;-) Thanks!

 

[Admin]

Thanks Scott, I hope this helped a little bit. There are lots of variables to consider with this kind of sophisticated product (both mechanical and electrical) but getting a solid foundation in electric bike theory can at least provide some guidance. On the flip side, there is an artistic quality to these things and I've always felt that a product I love from an aesthetic standpoint tends to satisfy me and I tend to take more pride in it and care for it better as a result. The higher end ebikes are like that because they will all perform pretty well but if there is one that you fall in love with, it might be worth trading one optimization or another for the joy that bike brings you... It's why I often buy red bicycles and add my own white pedals, it just feels right

 

[Scott]

Court,

I've been thinking about these numbers and, to be honest, it seems counter-intuitive to me that a smaller motor with a smaller battery can get greater distances, holding the speed constant.

• Pedego City Commuter 48V, 10ah: 500 watt motor, 480 watt hour battery = 480/500*20 = 19.2 miles
• Volton Alation 500 36V, 11ah: 500 watt motor, 396 watt hour battery = 396/500*20 = 15.8 miles
• Volton Alation 500 48V, 11ah: 500 watt motor, 528 watt hour battery = 528/500*20 = 21.1 miles
• Motiv Spark 48V, 10ah: 500 watt motor, 480 watt hour battery = 480/500*20 = 19.2
• Motiv Spark 36V, 15ah: 500 watt motor, 540 watt hour battery = 540/500*20 = 21.6 miles
• Neo Jumper/Carbon 36V, 9ah: 350 watt motor, 324 watt hour battery = 324/350*20 = 18.5 miles

I'm not a math guy, but it seems like we may be missing a factor here, but I'm not sure. Under this formula, we will always achieve greater distances where the numerator equals or exceeds the denominator, regardless of motor size or wattage output. For instance, a 24V, 5ah battery (if there is such a thing and it could reach the 20 mph threshold), would give us a 120 watt hour battery. If you pair that with a 100 watt motor (again, if there is such a thing), then you get 24 miles out of that setup. Compare that to a 48V20ah battery (960 watt hours) with a 1000 watt motor (again, if there is such a thing), which would only get you 19.2 miles under that formula. If you put those two bikes side-by-side with Court1 (24V5ah) and Court2 (48V20ah) riding each at 20 mph without pedaling, it is hard to imagine that Court 1 would go further than Court 2. What am I missing?

Also, in terms of upgradeability, if you have a 350 watt motor, are you limited to 350 watts or less of battery? In other words, could Easy Motion down the road provide a 48V20ah battery for its bikes with 350 watt motors? My sense is that that would be too much battery and it would burn up the motor without some sort of regulator to limit its output to 350 watts or less, but I don't know. If that was doable, then, under your formula above, you would be looking at a distance of roughly 55 miles. If that was the case, then the only question would be whether 350 watts of power would be sufficient in the relatively flat terrain of Florida. Just curious, on your Jumper, will it take off from a stopped position with the throttle alone (no pedaling) and, if so, what kind of surge is it and does that significantly impact your battery?

I appreciate your good thoughts.

Scott

 

[Ravi Kempaiah]

Just to reiterate Court's point, I would like to give an analogy;

For example, Apple computers have their own custom built UI and software and therefore they gel very well with the hardware and perform really smoothly without bluescreen shutdown or virus attack.
A PC for example might have top-of-the line Intel Processors, RAM etc but if the hardware and software do not match then it could still under perform. Also, having a seamless integration of electronics, battery and motor helps a lot.

There are different kinds of batteries and motors, for example, Prodeco Phantom X2 may have 500 watt motor and Pedego city commuter might have only 400watt motor but one is geared and the other is not. Therefore, Pedego City Commuter feels a lot more peppy and torquey..!

BMC or Dapu motors are highly rated compared to other ones, so what kind of motor, geared or not, what kind of controllers? and fine tuning? and how all of this is connected to the battery determines the range.

 

[FitzChivalry]

I would add (or, more accurately, reiterate what Court said) that range and power are only two factors to consider. For example, my wrist issues factored heavily into my decision to go with a cruiser style bike, and my shorter height of 5'7" pushed me toward a bike with a step-through (girl's) frame. These were more important to me than whether one bike gets me 2 miles farther than another, or gets me there 2MPH faster. My primary purchase incentive is to get to work, which is 19.1 miles from home. According to the review of the City Commuter, I should be able to get that far using only the throttle (without pedaling at all). I plan to pedal, so therefore the range issue wasn't as big a deal for me.

I totally understand the desire to compare bikes on the attributes that are measurable in a cut-and-dried fashion, but you really MUST consider other aspects, such as aesthetics, how a bike rides (such as whether the battery is in the middle of the bike or on a rack in the back), the number of gears, what type of propulsion the motor uses, and so on. Some of these really aren't quantifiable, and have to be gut-level decisions (how can you measure the aesthetics of one bike over another?).

Make sure you're weighting your results based on the aspects that matter the most to your planned use of the bike. In all likelihood, you're going to buy only one bike at a time, and as long as it performs well for you, you're not going to regret that you didn't go with Bike B instead. The guy I'd hate to be when deciding which bike to buy is Court, who has gotten to ride them all! Talk about being overwhelmed with too many choices!!

What I'd love to see compiled is one of those decision trees like they used to put in PC World magazine for laptop purchases. You'd decide what your most-important aspect was, your #2, and your #3, and it would make recommendations based on the order of aspects. If a longer battery life is more important than a fast processor, which is, in turn, more important than screen resolution, then go with Laptop A. Currently Court provides this on a case-by-case basis based on a few factors, such as rider weight, average terrain, and what you're using the bike for. Maybe we can come up with a decision tree one of these days!

 

[Admin]

Favorite quote of the day from Fitz "In all likelihood, you're going to buy only one bike at a time" unless you've got Baller Status!

Choice is such an interesting paradox because with it, we experience improved fit and efficiency but it also comes with regret. The more choices we have, the more possibility for fringe benefits at all angles which will never be satisfied perfectly for each unique individual. Awesome thoughts again Fitz, it ain't easy but with the right attitude any of these bikes are great, the technology is awesome it's just that there's always something "better" over that fence right.

Awesome thoughts on the decision tree, I've been thinking about trying to add filters to the website or some auto suggest tool but I enjoy helping one off like this (though you may notice slower responses at times due to the overwhelming nature of the job). Thanks again for chiming in Ravi and Fitz.

So Scott, I'm going to try and answer this for you elegantly: to achieve maximum enjoyment (power, speed) and range I suggest striking a balance between battery capacity and power and motor power. Indeed, I was not able to upgrade my older Pedego City Commuter to 48 volts after I switched to reviewing a 36 volt version. The motors and electronics were different. I'm not sure if this is the case for all ebikes but it seems like 36 volt systems work with 350 watt motors and 48 volt systems work with 500 watt motors... I know this isn't true of Optibike and Stealth models (which exceed 1000 watts) but maybe they have fancier controllers?

In any case, you've proved the many exceptions to the rule by sharing extreme examples of lower voltage motors paired with higher capacity batteries. I think what you'd find with one of these fictitious ebikes is that the motor would be strained and not perform optimally, potentially shutting off completely to avoid damage. This would certainly not reach the increased distances proposed through my formulas (which are just formulas passed along to me by bike company people).

My advice would be to compare the pros and cons of motors (geared = torque, lighter and smaller but not as durable over the very long term... I hate saying this because ebike companies always say their gears are bulletproof and don't want to spook people but really, gears vs. magnets? Magnets win over the long run) and then there is (gearless = bulletproof, heavier, may provide more friction when the bike is off as the magnets still repel each other with some designs, some of these motors enable regenerative braking) then assess your own needs on range and power and pick a size between 350 to 500 for most mainstream bikes and just double check the battery. Some bikes use their higher specs to sell a bike that is lower quality "cough ProdecoTech" but it will still work. My real complaints with their design is the battery mount anyway, the motor and battery cells are just generic.

What started as an honest attempt on elegance has become chaos clearly... So I'm going to try for your last question:

On your Jumper, will it take off from a stopped position with the throttle alone (no pedaling) and, if so, what kind of surge is it and does that significantly impact your battery?

My Jumper (and all of the Neo bikes) provide lots of torque, surprising get up and go with the twist throttle alone. It's really hard to tell what kind of impact that has on the battery but my guess (based on driving the Toyota Prius and watching the little animations) is that this uses a lot of power and also heats up the battery which decreases its life. Still, I rode my Jumper off road and zoomed all around town and it held up great! I'm going to quote an engineer from Currie Technologies (IZIP team) now to provide more technical feedback. This quote was taken from a response for the review I wrote about their 2014 E3 Metro but is applicable to most ebikes I would think:

On level ground at constant moderate speed, power demands are far less. Furthermore we strongly encourage pedaling [PAS mode] which further helps lessen power drain from the battery and judicially reserving throttle boost just for peak power needs, or when the legs need a break, so the ride is prolonged. Full throttle uses about 10A of power, but PAS consumes 2-5A depending on the mode.

 

[Scott]

Thanks much, Court, Ravi and Fitz. Hey Fitz, why did you go with the Pedego City Commuter over the Easy Motion City or Street? And I do plan to purchase three at once, which is, in part, why I'm being a little more deliberate, because I don't have baller status. ;-) Ha!

 

[FitzChivalry]

Scott, I ended up going with the City Commuter based on Court's assessment of my criteria. First, I have wrist issues, so I needed as upright a bike as possible. Second, I have a 21-mile-each-way commute to work, and can charge the battery at work. Third, my terrain is relatively level. Fourth, I'm 5'7" and so needed the step-through model vice the standard.

Court recommended that, based on my 172-lb weight, I go with the 48V model, which I did. There are no local electric bike dealers in the Charleston, SC area, so I had to rely greatly on research and advice from those in the know.

I've only gotten to ride my bike into work twice (a dry run on Sunday in which I rode 42 miles all at once... kind of a dumb idea, as my lumbar was killing me by the time I got home) and then again on Monday, but this time with 8 hours between riding in and riding home. Then the latest ice storm hit the South, and I've been sidelined by wooden shrapnel. I'm hoping to ride in again starting on Tuesday.

I still owe the site a write-up of my first commute on the bike. Look for that in the Pedego channel in the next day or two.

 

[Ray A Young]

Looking forward to your review.