Flywheel | November 01, 2022
Exploring the current state of batteries in micromobility with Shyam Srinivasan and featuring the top 5 vehicles of the week
Welcome to Flywheel, a weekly exploration of the used side of owned micromobility. Each newsletter will highlight an observation of trends emerging in the industry and feature five of the most interesting used vehicles being sold in the secondary market.
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The observation of the week explores the current state of batteries in micromobility with Zitara CEO/Co-Founder Shyam Srinivasan. This week’s featured vehicles are an ebike-emoped hybrid, a hubless urban commuter, a treat for F1 fans, a utility courier ebike, and the gold standard for bakfiet cargo bikes.
Observation of the Week
The Current State of Batteries in Micromobility with Shyam Srinivasan
Batteries are one of the most complex aspects of micromobility and arguably the most critical to get right. In addition to making up the majority of an ebike or scooter’s BOM, making a mistake with how you design, operate, or maintain a battery can have significant safety implications. To unpack all of this, I chatted with Shyam Srinivasan, CEO/Co-Founder of battery management software startup Zitara. It was an incredible conversation packed with so much information that I’ll be breaking it up into two parts. Here’s Part 1, which establishes the current state and challenges of batteries in micromobility:
What is the current state of batteries in micromobility?
“We’re still in the early days of adoption. Every industry goes through a learning process when adopting new tech like batteries. The Li-ion cells and control strategies used for micromobility were developed in the consumer electronics industry, which historically expects ~2 year lifespans. Ebike owners, especially those looking at the 2nd life market, want 5-10 year or longer lifespans. The industry hasn’t learned how to deliver that reliably yet.”
What does it mean to for a battery to be reliable?
“In mature industries like consumer electronics and automotive, reliability tests are designed in a multi-year process that apply statistical analysis to large data sets and expensive experiments to define tests that are predictive of real field failures. Standards organizations develop to drive adoption of best practices.
For ebikes, this should look like all kinds of vibration and shock testing, exposure to extreme temperatures, water, sand, and other challenges while treating the battery pretty harshly, rapid discharges at low temperature, overcharging, storage at full charge, etc.
There are some basics standards (i.e. UN 38.3 & UL 2271), but they are very general and not comprehensive. Because there’s such a wide variety of cells and pack architectures out there, the standards organizations leave it up to the manufacturers to do a lot of the lifting in terms of figuring out how to ensure reliability in their particular application.”
Why are ebikes the harshest consumer use-case for batteries?
“A big part of the problem is that it’s still a relatively new industry. An ebike needs to meet many of the same challenges as a car (i.e. riding across bad roads in bad weather) without the century of institutional expertise and large budgets for engineering and testing.
Thus, ebike OEMs are all making up their own internal standards, and approaches vary wildly. If you are a budget OEM, you might only test to the bare minimums required by the standards. If you are a premium OEM, you might be doing much more rigorous testing, but maybe not – it all depends on the in-house expertise in accelerated life reliability testing, which is a difficult science. Often in an effort to compete on cost, manufacturers select cheap battery management systems that allow packs to degrade much faster than necessary.
This is a solvable problem. The industry needs to get smarter about the trade-offs between price and quality. They need better tools, to understand the capabilities of the battery during design and operation with ability to prevent failures before they happen.”
What are the most common types of failures for ebikes?
“Water ingress is by far the biggest issue. There’s a design tension between great waterproofing and managing the heat of operating a battery. Engineers make careers out of solving this kind of problem well, and it doesn’t appear that many of them have come to the micromobility industry.
Mechanical damage is the 2nd most common. Dropping a bike, or just a big pothole, can create issues with connections in the pack, which then causes a short that leads to excess heat generation. When something in the pack gets hot enough, it starts a thermal runaway event that leads to failures.
Cell manufacturing issues are actually quite rare for cells from reputable suppliers, it’s much more likely a problem with the design of the battery pack, enclosure, or controls.”
How does the way people charge their batteries impact battery health? Why do OEMs not control this by software?
“It isn’t just charging, there are many complex trade-offs between battery longevity and performance. In general, charging or discharging quickly (covering the full capacity well under an hour), especially at extreme temperatures, degrades the battery faster than more gentle use. Storing a pack at full charge (or leaving it plugged into the charger) for extended periods is also bad. It is great as a user to have the battery full when you’re ready to ride, to go fast, and to recharge in 15 minutes, but these experiences have a cost in battery health.
OEMs do control the battery use with software, but often with bad software. Their interests are not well aligned with secondary market buyers. OEMs typically compete in the new market on range or power (and price), and therefore have to make trade-offs for battery life, which is not well measured in the market.
OEMs are incentivized to advertise a large riding range – it's a big consideration in a competitive market. It's often a more important selling point than battery life, which is often ill-defined, rarely even tested, and never warrantied beyond a couple years anyway. With intelligent software, most OEMs could strike a much better balance, getting optimum energy and power from their battery system while minimizing degradation.”
For ebikes that are already out there, what can people do to maximize the health and safety of their batteries? How can people evaluate the health and residual value of their batteries?
“As a used ebike buyer, you really need to get as much information as you can:
Inspect for any signs of physical damage to the vehicle, especially its battery system. If it looks like it has been dropped or has visible water damage anywhere, walk away.
Ask about how the owner used, stored, and charged the bike. Where did they keep it, did they leave it plugged in overnight, what was their usual or favorite ride.
As an owner, you have to deal with the really poor information you get about the battery – often just a few indicator lights for the state of charge. Without OEMs designing better controls and information systems, you’re stuck following general tips:
Store the bike indoors, unplugged.
Don’t operate it all the way to empty, try to complete your ride with 20% capacity or more.
Don’t charge it to full. You’ll need to wing it, but try to only charge enough for the trip you’re planning and some reserve.
Discharge the bike to 30-50% and keep it in a cool, dry place (unplugged) for any long term storage.”
Consumer electronics have set a cultural behavior where you charge devices to 100%, keep them plugged in overnight, discharge to 0%, etc. Since ebikes aren’t like other consumer products (larger MSRP and bigger consideration of residual value), will customer behavior around caring about battery health and how they charge change? Or is this just something ebike OEMs will have to design around?
“You’re absolutely right that there is a residual value problem for micromobility and other long-lived, battery-powered assets that requires a different approach than we see today. A used ebike buyer can’t easily and confidently determine the health of a battery, and can reasonably assume that the battery will need to be replaced soon after purchase. That justified skepticism (adverse selection for the economists) is why the automotive industry has lemon laws and ultimately slows the adoption of micromobility.
The core of the problem is that there isn’t a standard definition for state of health (SoH). This is a pet peeve of mine. SoH is presented by OEMs and “battery analytics” companies as an arbitrary % score. It’s often not actually based on any real measurement and is just a pre-programmed value that counts down based on how much the bike has been used. Today's SoH estimates have little, if any, correlation with the actual battery performance. It is possible to accurately estimate a battery’s capabilities with better modeling and software, but this is extremely difficult to do and it’s what Zitara specializes in. In the case of an ebike, this means measuring things like real range, speed, torque, hill-climb, and charge time. It also means being able to adjust battery operating parameters dynamically to balance immediate performance and long-term health at every stage of the battery’s life.
In order to continuously optimize batteries for performance and profitability and enable safe and productive 2nd life batteries, Zitara believes that OEMs must use software that automatically keeps track of what's happening inside their batteries - everything from SoC/SoH, to live and predicted behavior, to degradation, and to detection of safety risks and abnormalities.”
Keep an eye out for Part 2 of this interview, which will dive deeper into the ways in Zitara solves these challenges and optimizes safety, performance, and profitability for batteries in micromobility.
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Top 5 Vehicles of the Week
The Onyx RCR is an ebike-emoped hybrid that blitzed the market by providing motorcycle-like performance at the price of an ebike. Powered by a monstrous 182Nm, 3kW rear-hub motor and 1.66kWh battery pack, the RCR can hit 60mph and a range of 75 miles. A front suspension fork and dual rear coilover suspension system help temper these speeds and make the RCR surprisingly stable. The RCR is technically classified as an ebike due to its pedals and a street-mode that limits the powertrain to class 2 or class 3 speeds and throttle functionality. However, the RCR is one of many scrambler ebikes in a regulatory and UX gray area that blurs the lines of ebikes. They hit motorcycle-level speeds and torque without requiring a motorcycle registration or license (in most US states), and they are frequently misused (ridden above 28mph) and make others in the bike lane feel uncomfortable. From my friend David Moll that recently experienced this:
“One of those ebikes with “there for decoration” pedals just blew past me in the bike lane. New rule of thumb - if you’re wearing a motorcycle helmet, you’re definitely no longer on a bike lane bike.”
This specific listing was bought less than 6 months ago and has ~600 miles of usage. It was recently inspected/serviced by Onyx and comes with proof of purchase. Listing can be found here.
Thee Beno Reevo is a futuristic class-3 hubless ebike. Launched on Indiegogo in late 2020, the Reevo has been one of the most anticipated crowdsource ebikes. The powertrain features a 750W hubless motor custom designed by Beno and a removable 504Wh battery pack. The motor actually drives the hubless wheels with directly coupled gears, which is a much more efficient system than the friction drive many other hubless wheel concepts use. There’s also a number of impressive software innovations on the vehicle, from a three-stage theft prevention system (fingerprint biometric key, invisible wheel lock, and GPS tracking) to front and rear lights/turn signals that are directly integrated into the wheel frames. The Reevo’s Indiegogo campaign has been met with lots of skepticism, due to previous undelivered and underwhelming hubless ebike concepts like Cyclotron and significant shipping delays. However, Beno has just recently started shipping Reevos a few months ago and initial rider reviews have largely been positive. This listing has <100 miles of usage and has a 1-year transferable warranty. Listing can be found here.
Although it’s a departure from the usual Flywheel feature, this is a bit of a treat for my fellow F1 fanatics. This listing is a Go-Kart styled after Ayrton Senna’s 1987 Lotus 99T. Bought about 30 years ago by the original owner, the vehicle features yellow fiberglass bodywork sporting the iconic blue Camel livery. It’s powered by a 5HP Briggs & Stratton Single gas engine, which is an engine typically used for medium-duty industrial/commercial applications like tilling or snow blowing. This listing is found on Bring a Trailer, “a digital auction platform for classic, collector, and enthusiast vehicles,” and one of the original inspirations for Flywheel. My favorite comment from a potential bidder on this vehicle’s auction site: “I would actually HAVE A KID just so I could drop him (or her) in this kart.” Listing can be found here.
The Zoomo Zero is a class-3 delivery ebike. Designed for couriers and other high-utilization urban use-cases, the Zero is optimized for easy maintenance and high reliability. The powertrain features a strong 80Nm front geared hub motor that is paired with a 628Wh battery pack that is neatly integrated into the downtube. The rear rack comes standard with the vehicle and is also directly integrated into the vehicle frame. This listing is in like-new condition with a Flywheel estimated ~800 miles of usage, and is a retired “Certified Refurbished” vehicle sold by delivery ebike subscription service Zoomo. As outlined in a previous edition of Flywheel, Zoomo is one of the most interesting sellers of used ebikes in the US and a great case study in how regular diagnostics and maintenance of vehicles in their first lives massively improves their residual value and reliability in their second lives. Listing can be found here.
The Riese & Müller Load 60 is a class-3 cargo bike and the ultimate minivan replacement for families. It sets the standard for bakfiet cargo bikes due to its impeccable rideability and premium componentry. The vehicle is powered by Bosch’s 85Nm Performance Line CX mid-drive motor and 500Wh Bosch PowerPack, and the full-suspension frame has a front cargo box that is incredibly versatile and easily customizable with accessories (from R&M and other aftermarket suppliers). Bakfiet cargo bikes are typically more comfortable to ride and easier to load with cargo than long-tail bikes, but their larger size means that they’re more difficult to store and park. As such, they’re great for families with garages in more suburban/less busy areas. Although a new Load 60 costs more than most used cars, a used Load 60 with relatively low usage (~1400 miles) selling for $3K less than the Flywheel Vehicle Value is an excellent option. Listing can be found here.
That’s it for this week. Thanks again for joining, see you next Monday!
- Puneeth Meruva
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