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Flywheel: Making batteries safer with Zitara | Vehicles from VanMoof, Cowboy, Aventon, Ride1Up, & Sondors

Exploring how Zitara makes micromobility batteries safer & featuring the top 5 vehicles of the week


Welcome to Flywheel, a weekly exploration of the owned and used 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 how battery management startup Zitara makes micromobility batteries safer with their CEO/Co-Founder Shyam Srinivasan. This week’s featured vehicles are two software-enabled commuters, a compact cargo bike, a scrambler with emotorcycle-esque power, and an all-terrain SUV of ebikes.

Observation of the Week

How Zitara makes micromobility batteries safer with Shyam Srinivasan

We’ve talked time and time again about the importance of batteries in micromobility. They are the biggest safety risks, the core economic drivers for the residual value of a vehicle, and the core UX drivers for customers. I interviewed Shyam Srinivasan, CEO and Co-Founder of Zitara, back in November 2022 about the current state of battery systems and the unique challenges they face in micromobility. I’m excited to have him back on Flywheel today to talk about how his startup Zitara helps tackle them. Please welcome back Shyam:

“Hey Shyam, it’s great to have you back. As per our previous chat, can you recap some of the most serious challenges facing ebikes today, and how the software Zitara is building addresses them?“

“We started Zitara to help customers design and operate battery systems safely and profitably. Ebikes, and micromobility broadly, are still young industries. OEMs are figuring out how to develop products through complicated offshore supply chains without the established best practices and regulations available to more mature markets, all while facing stiff economic headwinds. Our customers, like most of micromobility, rely on outsourced battery pack engineering and manufacturing that can vary dramatically in quality. These dynamics result in a few clear problems we see across the ebike world that Zitara can help with:

We aren’t surprised by any of these challenges in an emerging industry. Zitara helps manufacturers and fleet owners navigate these issues by bringing certainty to battery design and operation through software.”

“When should a company think about bringing Zitara into the loop to address these problems?”

“We are able to support customers across the product lifecycle, under a variety of constraints. The great thing about our software solution, compared to a hardware system, is that we can engage anywhere from the initial design to retrofitting existing fleets on most BMS configurations. 

We find that companies that have shipped more than 10K vehicles have encountered the problems we’re talking about. Zitara can work with these customers to quickly get a handle on safety and performance issues. It is rarely too late for Zitara to make meaningful improvements to the operation of a battery pack, even when the hardware design is fixed.

For customers that are designing a new vehicle, there are more options, and Zitara can help companies better understand the levers they have to get the most from a battery system. That can include services like subscription testing to develop a robust supply chain and simulation tools to balance accuracy and cost in a pack design.”

“What are the Zitara product offerings, and how do customers engage with it?”

"We have two core products: Zitara Studio and Zitara Live. Zitara Studio is our service for helping customers characterize, qualify, and simulate batteries so they can design the best possible packs. Zitara Live is our real-time solution that provides precise monitoring for every vehicle, reporting range, health, and safety feedback through the embedded and cloud software that best suits our customer. 

Both products are built on top of high-quality models. You can only measure the voltages, current, and temperatures in a battery pack, everything else is a model. Zitara makes high-performance models and transparently reports the validation performance in use cases that matter to our customers. To make these models, a customer sends us samples of their cells and packs which we will characterize for their application in our lab. The process of testing and building models is part of the Studio subscription; the models are then available in our simulation tools. 

Zitara Live combines the same models with control software to deliver actionable feedback to the vehicle control systems and fleet management dashboards. To run embedded, we need a modest amount of compute and access to sensor readings. We support a wide range of onboard processors, including those that are often built into the pack BMS or popular vehicle IoT modules. This flexibility allows Zitara Live to be retrofit onto fleets with a straightforward software update.”

“Could you talk a bit more about Zitara Studio?”

"Zitara Studio is our design-time software, which helps OEMs characterize cells and packs, qualify cells, and leverage simulation to build the right pack for their application. Our ebike customers use it to qualify the large stream of cells and packs they must qualify and continue to monitor in a mature supply chain. Zitara Studio also offers tools to analyze the lifespan of their batteries and understand performance from beginning to end of life. We help answer critical questions around predicting heat generation, the impact of electrical parasitics, and how range and power may degrade across use cases.

I want to emphasize the supply chain point. My background is in consumer electronics, where the ongoing reliability testing processes are firmly established. Zitara Studio gives micromobility companies an opportunity to apply this approach by continuing to test cells throughout the product life cycle and give apples-to-apples comparisons they can’t get from battery manufacturers.”

“Does the importance/effectiveness of these tools vary with off-the-shelf packs vs. in-house packs?”

“There really is no such thing as a true off-the-shelf battery pack at the volumes an OEM needs to hit to be successful. Even something as simple as a screw is effectively custom made to a specification in production settings. Bosch may be the only exception here serving companies that are differentiating their products on something besides range and powertrain (and can command the premium price point required to incorporate Bosch components profitably). Anyone that has sourced more than 10K packs knows that every design and supplier is a snowflake and the OEM is responsible for driving quality through good specifications and continuous monitoring. Zitara is the expert partner here.”

“How does Zitara Live build on the modeling you do in the lab?”

“Zitara Live creates the feedback loop between sensor data and those high-performance models. The really critical take-away is that there is no ‘typical’ battery pack. Each vehicle experiences different riding styles and environments. This variety isn’t addressed by most BMS monitoring solutions on the market. They are static, and don’t change with the asset as its capabilities degrade over time. Zitara Live is always learning and fine-tuning the model from its laboratory defined initial parameters to reflect the health of each specific device. It provides accurate, predictive signals for the vehicle controls to accommodate the battery state of health and anticipate risks that require safety shutdown.

Zooming out from the individual vehicle, these unique model evolutions can be aggregated into fleet level insight about battery performance that can drive better operational decision making and inform future design iterations.”

“You mentioned earlier that Zitara Live can be a retrofit, are the sensors that are already on a pack sufficient for the modeling and monitoring that you do?”

“The models that we develop in the lab are based on the same types of sensors that are in every pack today: current, voltage and temperature. So our models are already designed to be compatible with hardware that is in every battery pack across industries. That said, the quality of these sensors will have an impact on observability – basically the upper limit on accuracy in state of charge or state of health estimation that is possible for a given sensor array. We can show designers and OEMs precisely what the observability limits are for their existing hardware as well as the incremental gains they could see with improved sensing.

For example, many 48V battery-makers for LEVs have converged toward three inputs for temperature measurement and few customers have questioned whether that is adequate observability for catching thermal anomalies. Zitara gives our customers a clear picture of how well the temperature sensors can work for safety applications (the observability of a safety event) and how additional sensors could make the pack safer.”

“When companies are considering Zitara, what are their biggest sticking points or concerns? Is it that they already get a BMS from their suppliers, a false sense of comfort around battery health, or something else?”

“There are three key customer concerns we’ve encountered:

First, exactly what you’re alluding to, many customers ask: ”isn't my vendor doing this for me today?” The unfortunate, blunt answer is no. We started Zitara because BMS and pack vendors aren’t keeping up with innovation in battery applications. The incumbent technology is rooted in managing a laptop or cellphone, not an ebike that has replaced a family car.

Today’s BMS hardware is still doing important work, primarily making sure the operating voltage, current, and temperature ranges are enforced. But they also provide a state of charge and often state of health number, which are typically generated from rudimentary software algorithms and don’t come with any guarantees about their accuracy. As a pack ages, these estimates get worse as each unique device degrades differently. This uncertainty forces operators to retire vehicles early, leaving significant value on the table, or risk safety events by keeping vehicles in service too long. Zitara guarantees our algorithm performance across the life of an asset under management because we’ve built a system that is tailored to each application and device, not some hypothetical lowest common denominator.

The second hurdle is about how Zitara proves our claims. This is where testing batteries in our lab and running onboard packs comes into play. We test across a variety of conditions, including application specific aging, to gather the data necessary to train models and validate them against ground truth cycles developed in coordination with our customers. We do this transparently–customers have full access to the raw test data and validation performance reports. If a customer has a concern about a specific failure mode, we can also induce the failure and demonstrate our ability to identify and react to it safely. Outside the lab, Zitara Live can monitor the quality of the algorithm's predictions on an ongoing basis by comparing a Lookahead prediction (ex. after discharging for two minutes, the pack voltage will be X) to the actual sensor values over time. Even better, we can close the feedback loop by aggregating the device level insights in the cloud to support operating decisions and informational dashboards.

The third sticking point is around integrating Zitara. I’ve already mentioned Zitara Live can be retrofitted onto a wide range of systems, but we find that the least vertically integrated customers are the most intimidated by introducing customized software. We help them understand that, as long as they have control of some onboard software, or do sufficient volume with a supplier (≥10K vehicles / year), they have the power to integrate Zitara. We have a fantastic applications engineering group to help customers realize the most value from Zitara Live. We find this concern is mostly about doing something unfamiliar. OEMs need to remember that the battery pack is a critical part of the system. Its health drives the residual value of a vehicle, the user experience relies on predictable power availability, and a poor safety record is an existential threat to any business in this space. If they need to be controlling any part of their design tightly, it is the battery pack.”

“It feels like the lifetime analysis you do is auto grade. The problem I’ve heard time and time again with ebikes is that most OEMs don’t really know what their vehicles will look like when they’ve been used for 1000s of miles, so they can’t engineer around it. It sounds like Zitara provides the data they need to be able to do that?”

“That’s a great way of putting it. To give you some context though, ebike OEMS are generally not even meeting a mass production consumer electronics standard for understanding their warranty risk. While I was at Apple and Google, we used to test batteries for a year and a half before even beginning the development cycle for a new product. We’d have the battery design close to locked before we began a 12-18 month design cycle for the end product, and even small changes to the battery could drive a full program reset. In the ebike world, many OEMs begin testing batteries within a few months of a product launch. By that time the first production orders are already due to pack suppliers, there is no runway left to respond to what the tests reveal, especially with the typical BMS. 

Our Head of Applications Engineering, Daniel, led the battery team at Gogoro (a pioneer in battery-swapping in Taiwan). During his tenure he set an extraordinarily high bar for safety and pushed the lifetime of their battery packs from a year or two to over ten years. He likes to point out that the algorithms and analytics were the key to realizing the value from all the investment in mechanical, electrical, and supply chain design aimed at improving quality, safety, and profitability. Zitara is making the critical algorithms and analytics available and easy to integrate for our customers, so that they can focus on designing the products that their customers need.”

You can learn more about Zitara here.

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Top 5 Vehicles of the Week

S5 Foam Green

Released just this past Tuesday (March 9, 2023), the VanMoof S4/X4 is a class-1 commuter that aims to be a simplified and more affordable version of its $3,998 S5/A5 sister series. The S4/X4 sticks to the basics and provides an uncomplicated, elegant ride suited for the average commuter while still maintaining many of the iconic design aesthetics and features VanMoof has come to be known for. Its powertrain features a 250W (~59Nm) front hub motor and a 478Wh battery pack, which is controlled by a cadence sensor vs. the S5/A5’s torque sensor. While the S4/A4 retains the popular boost button and the rear wheel kick lock and alarm system featured on other VanMoof’s, it eliminates Apple Find My integration as well as the three-speed automatic e-shifter transmission. The S4/A4 actually also doesn’t have an integrated display, and instead comes with a detachable phone mount so that riders can use the VanMoof app on their phones as the UI for the vehicle. In addition to lowering the vehicle cost, one of the main reasons VanMoof seems to have simplified the vehicle and included fewer complex components/features is to reduce maintenance issues. From CEO and co-founder Ties Carlier: “We spend a lot of time listening to our prospective rider. And what we heard clearly was the desire for our key features and iconic VanMoof design — in an ebike that was even more simple, more accessible, and more reliable.” Listing can be found here.

The Cowboy C4 is a class-1 commuter that rivals VanMoof in the race for software-enabled ebikes. Like VanMoof, Cowboy employs a similar level of vertical integration that enables state-of-the-art software and electronics UX features like over-the-air updates (i.e. their recent adaptive power update), theft detection, GPS tracking, and an “integrated cockpit” that allows riders to dock their smartphone on the vehicle and use it as the vehicle’s UI. The C4 is one of the few ebikes to have crash detection, which is a notable safety feature particularly useful for people new to urban riding. Its powertrain features a 45Nm rear-hub motor and a 360Wh swappable battery pack, and is combined with a belt drive. This listing has never been ridden, has only been charged twice for firmware updates, and has a transferable warranty active until 4/15/24. The MSRP of a C4 was raised from $2,990 to $3,490 back in March 2022, so this listing for a brand new C4 for ~$1,500 less than the new MSRP and ~$400 less than the average resale price is a steal. Listing can be found here.

The Aventon Abound is a recently launched class-2 compact longtail cargo bike. Its powertrain features an 809Nm geared rear hub motor and a 720Wh battery pack, and is capable of a 440lb max payload capactiy. The motor is controlled by both a torque sensor and a throttle, which are both excellent additions to a cargo bike. Since cargo bikes are often heavily loaded and can be challenging to maneuver, the torque sensor and throttle help ensure that riders can maximize the utility of their vehicle and get smooth, instantaneous motor assistance that makes the ebike significantly easier to ride. This vehicle is cargo-optimized right out of the box, and comes standard with hydraulic brakes, a suspension fork, integrated rear rack, running boards, turn signals, and a dropper seat. The Abound is priced somewhere in between premium brands like Tern or Urban Arrow and the budget brands like Lectric and Rad Power, and as such provides a unique hybrid of the quality and service network of a high-end brand with the affordability of a budget D2C brand. This listing was bought 2 months ago and has a transferable two year warranty. It has been ridden for <175mi, and is being sold because the seller wants a larger longtail cargo bike like the Yuba. Listing can be found here.

The Ride1Up Revv 1 is a class 2/3 hybrid scrambler. While it may look like a Super73, the Revv 1 rides like a sturdy emoped or emotorcycle. Its monstrous powertrain features a 95Nm Bafang geared rear hub motor and a 1040Wh battery pack. The Revv 1 is limited to 20mph out of the box as per class-2 ebike regulations, but it can be unlocked to up to 37mph in off-road mode. Enabling off-road mode on the Revv 1 requires riders to contact Ride1Up directly to get unlocking instructions, which is a great safety feature that adds one extra step and friction point to help prevent just anyone from unlocking the vehicle and using it unsafely, in bike lanes, etc. To soften this massive powertrain, the Revv 1 combines excellent build quality frame with 20” by 4” fat tires, dual suspension, and hydraulic brakes. The Revv 1 is simply an incredibly solid ride. As Micah Toll puts it, “As someone who rides high-power electric motorcycles, this ebike gives me that [solid] feeling.“ Ultimately, given that this is an ebike built for 30mph+ riding, the Revv 1 feels exceptionally safe and sturdy when used as a class-2 ebike. This listing has been “ridden only a few miles” and is the best bang-for-your-buck scrambler with moped-esque performance out there. Listing can be found here.

The Sondors LX is a class-2/3 all-terrain SUV of ebikes. Its powertrain features the ultra-high performance 95Nm Bafang Ultra mid-drive (controlled by a torque sensor) and a 1008Wh custom battery pack made of LG cells. There’s also a 7-speed Shimano transmission which is protected by shift detection, which is a must-have given the power of the Bafang motor as well as the fact that mid-drives generally cause much higher wear-and-tear on the transmission. The vehicle is capped at 28mph out of the box, but it does have a 35mph off-road mode. It also features massive 26” by 4.9” fat-tires, a front fork suspension, and a suspension seat post, all of which help smoothen virtually any surface you may ride the LX on. All things considered, the LX is remarkably affordable despite its massive powertrain and excellent rider comfort features. It’s also one of the only mid-drives in the market with a throttle. As one of the only mid-drives that Sondors sells, the LX “is the most complete bike you can buy from them [Sondors] right now”. Listing can be found here.

That’s it for this edition. Thanks again for joining, see you next week!

- Puneeth Meruva

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