Background: I had the opportunity to sit down with Julian Seume, Chief Marketing Officer from Wiferion, and learn more about his company and their wireless battery charging solution for autonomous mobile robots (AMRs) and automatic guided vehicles (AGVs).
Editor’s Note: This interview has been edited and paraphrased for clarity and length. The content represents the intent of the speakers interviewed.
Mobile Robot Guide (MRG): Can you give our audience an overview of Wiferion, who you are, and how you got started?
Julian Seume: Let’s start from the beginning. We are a small company of roughly 40 people based in a very small town in Germany called Freiburg. It’s on the borders of Switzerland and France. If you drive 30, 40 minutes in either direction, then you’re in another country, which is of course one of the loveliest parts of Europe.
This area of Germany is known as the most sunny place in Germany. It has one of the biggest research institutes for solar power, called the Fraunhofer Institute for Solar Energy Systems (ISE) <https://www.ise.fraunhofer.de/en.html>. The Fraunhofer Institute is a huge institution and organization that has many, many different locations and different topics of research.
The Fraunhofer Institutes, for example, were heavily involved in the development of the MP3 file format or high efficient solar power inverters. They invest in research and development, and the idea is to transfer these solutions into businesses.
In our case, there were four people actually working on optimizing solar energy converters. For example, how to optimize the transfer of DC current to AC current and how to get the best energy out of sunlight. Two other guys were working on a project doing an inductive charging solution for an electric vehicle. During their research, they actually found a solution to transfer 22 kilowatts of power over a gap of 20 centimeters, with an efficiency of 95%.
This was some kind of a world record and an official start of the whole Wiferion story. Electromobility (e-mobility) was the first real application market because that was where they were working and researching.
However, as we all know, e-mobility in cars, besides Tesla, is still on a very small market. The four founders found actually that there is a business, or there is actually an industry, that is transitioning to electrical power and that’s, the industry of industrial forklift e-vehicles.
Automatic Guided Vehicles (AGVs) and Autonomous Mobile Robots (AMRs) mainly run on batteries. They are also changing from the old traditional lead acid batteries into lithium batteries. This is a perfect match because lithium technology is also much more convenient and better suited for fast and powerful charging cycles. Lithium is also much better for short, intermittent charging cycles without ruining completely the battery life.
So the founders of Wiferion developed a battery charging system not for cars, but especially for AGVs or AMRs or industrial trucks (fork trucks and tuggers). This industry segment is ready for the adoption of high energy charging solutions.
So the first product we developed is a three kilowatt system, that is already on the shelf for almost two years now. It’s been in production since the middle of 2018.
MRG: Are you selling your solutions in North America yet?
Julian Seume: So, COVID is of course not a full showstopper, but it’s made the show not so much fun at the moment. We are looking to come to the U.S. market quite soon. And of course, as a European manufacturer, it’s most important to get the certification for FCC and UL.
So that’s something where we’re working on. And I cannot tell you but we have some systems already running on-premises in the U.S. which are of course testings. They of course are highly confidential at the moment, but hopefully that’s going to be successful and then there’s going to be a good opportunity for us to go to the North American market.
MRG: Can you give us an overview of wireless charging? How does it work?
The system basically consists of two parts, or coils. One coil is stationary, and one coil is mobile (on the vehicle). The stationary part consists of a wall box that’s connected to the facilities power.
The wall unit contains a control unit and the power coil is placed either on the ground (embedded in a mat) or affixed to a wall in the facility. The mobile unit is attached to the vehicle, on the side or on the bottom (so that it can align with the stationary coil). The most common scenario is to place the (receiving) coil on the bottom of the vehicle. On the vehicle is a second charging control unit that manages the transfer of power from the coil to the battery. The two control units (one stationary, one mobile) talk to each other in order to control the flow of electricity.
As soon as the two plates (or pads) are aligned with each other, the systems start talking with a wireless signal. They exchange information like: How full is the battery? How warm is the battery? How warm is the vehicle? Depending on the status of the battery, and how much energy the vehicle still has, the process of charging immediately starts by energizing the magnetic field in the charging pad.
Energy transfer happens simply by creating a magnetic field in the bottom coil that transfers the energy to the receiving coil on the vehicle without a physical connection. Nikola Tesla invented this inductive transfer process in 1888, so it’s been around quite a long time. The real breakthrough by Wiferion is in improving the efficiency beyond 90+ percent. You likely have already experienced this wireless charging technology in your smartphone or your electric toothbrush.
In the smartphone example, efficiency is around 60%. This is not a big issue at lower energy levels of your smartphone battery. However, at higher energy levels, small losses become significant, and that’s what we’re solving.
There are already competing solutions on the market, but from our experience, we are maybe one and a half to two years ahead of the competition. This is especially true at higher energy levels. Wiferion is able to transfer energy at levels constantly 5-10x higher than the current competing solutions.
For the European market, our initial approach was to help AGV manufacturers where the value is clear and simple. A typical AGV has to spend one-third of its life standing idle on a charging station. That’s inefficient. On the other hand, it’s not efficient to have a person dedicated to just managing the AGV charging cycles, swapping batteries or plugging and unplugging charging cables. So our solution actually fits very well into that story of being more autonomous and more flexible.
The other option for solving automatic charging is to use contact-based charging stations, but there is still some big differences compared to inductive charging. If you have a self cleaning robot in your house, it will roll around by itself and go back in the evening to the little charging stations. If the robot mis-aligns on its charging station, it may not be recharged. Dirt and other debris can collect on the contacts and reduce charging efficiency. Lastly, contact based charges are uni-directional, the contacts always have to align properly to put the positive and negative contacts together without shorting out the system.
Inductive charging solves many of these issues. Dirt and debris aren’t an issue. The coils have no directional requirements – they just need to be close to each other.
It also doesn’t matter if the system is charging a 24 or 48 volt battery. For example, with one charging pad we can charge a 24 volt lead acid battery and then, and then, immediately afterwards, charge a 48 volt lithium ion battery vehicle. The system automatically realizes what kind of battery is coming and how much energy it will need. This means that a single charging station can be used by any type of electric vehicle in the facility.
Finally, there’s no “getting hot phase”. This means that in less than a second, full power can be transferred to the magnetic field. Other solutions have a ramp up time of five or 10 seconds. In a 30 second charging cycle, this wastes 25% of the charging time.
This is important because we think that the process of charging should be not a process that needs to be separate from the daily operations of the AGV. The vehicle should just go through its normal motion and the charging cycles should be integrated into those normal operations. This brings us back to the idea from the beginning. The main issue is: it’s not about the battery size or how good the battery can store the energy, it’s how easy and fast we can transfer the energy from one point to another.
MRG: When you talk about a 30 second charging cycle, how much energy in terms of milliwatt hours or watt hours, are you talking about can be transferred in that short period of time.
Julian Seume: I want to quickly explain that now. It’s important to understand that inductive charging can be done in most of the cases, but it’s not always a perfect business case.
Let’s assume you have a certain route for your tugger train. Starting from a pickup point for the materials it makes a route to five other locations (stops) in the factory. At each stop it delivers two packages. The tugger might stop 25 times in an hour as it waits for material to be loaded or unloaded.
If we place a charging pad at each stopping location, we can transfer three kilowatt power in 30 seconds. From there it’s just a matter of the “C” rating of your battery [Editors Note: C Rate is derived from Coulomb’s Law developed by French physicist Charles Augustin de Coulomb. The C-rate is the governing measurement of what current a battery is charged or discharged at. For example, the posted mAh of the battery is the 1C rating. If a battery is labeled 2000mAh, then its 1C rating is 2000mAh.] If we charged with, for example, 60 amps, and then it’s just math, how long it will take and what kind of C rate you have on your battery side? So, if you have a one C or a two C of course, we talk about a good lithium ion technology. They are either LTO, which is even higher five and four C’s or LFP where you can easily get to one C or one and a half. It then really depends how the system is being designed, but we try to optimize together with the AGV manufacturer or OEM that they can combine the perfect battery match with our fast charging wireless charging pad.
This is called in-process charging, and it enables the AGV or tugger battery to remain near fully charged during the majority of its work day. We really believe these kind of technology innovations will change the way electric vehicles will be used and charged in the future.
This is a game changer for the electric vehicle market. At the moment, most of our customers are AGV manufacturers who see the advantages of opportunity charging.
One of our customers in Spain is an AGV/AMR company called ASTI. They have implemented the first European, outdoor, fully automatic tugger train for car manufacturer SEAT. They have a fully autonomous AMR that brings parts from the logistics center to the production line. These AMRs drive outside of the buildings a lot, because it’s a huge plant. What we have implemented is an outdoor charging point that’s IP65/IP68 rated. This means that it is waterproof and dust proof so it can stay outside regardless of the weather. It has no contacts to corrode. The magnetic field is transferred even through plastic and other materials.
MRG: Interesting. So you’ve created a charging solution for any industrial electric vehicle, whether it is an AGV, AMR, tugger or fork truck?
Julian Seume: For us, it doesn’t really matter. It comes along with the evolution from lead acid batteries to lithium ion batteries as well. We can perform any charging cycle, including the older battery chemistries.
With the adoption of lithium ion batteries comes the opportunity for the short burst opportunity charging processes. There will be of course, many lead acid applications, but we can see more coming of that smarter battery long life and being able to get fast and powerful energy at once.
That’s actually where wireless charging comes into place. And for us it doesn’t matter if it’s smart robot or if it’s an AGV, as long as it uses some kind of electricity. As I said, there’s many applications where wireless charging is possible, but not everyone has the use case where it’s really needed. The system itself has still a higher CAPEX, which is a little bit more front up investment. But there’s no wear and tear. You can have one system that is able to charge multiple battery types and therefore multiple vehicles. Lastly, the charging pad can be placed in areas with multiple approach paths, allowing you to optimize the operations.
Lastly, not only do we sell the wireless charging system, but we’re also a battery supplier. This means that we can source batteries that we know are optimal for the charging system and the application. We can validate the quality of the batteries/suppliers and ensure that the batteries don’t fail during charging cycles.
We’re also managing all of the data about the charging cycles for all of the vehicles. This data is communicated between the onboard vehicle chargers and the stationary charging stations every time the vehicle stops for a recharge. For example: What’s the status of the battery? What’s the status of the vehicle. This data is consolidated in the cloud and can be used for conditional monitoring, fleet management, predictive maintenance. So you actually reduce again, stopping times and breakages of your vehicle fleet, because you are always on top of what’s happening.
MRG: Can you clarify this? Are you using wifi to do that? Are you doing that over the power signal?
Julian Seume: It’s an RFID signal actually. We don’t use wifi because wifi is always difficult to use in industrial environments. Some of our competition actually use wifi or even Bluetooth, and struggle to get good communication.
MRG: RFID. Okay. So the signal is not coming over the inductive connection?
Julian Seume: No. The RFID has no interference. The other special thing is that communication starts even before the vehicle arrives at the charging pad. This allows the charging unit to immediately setup the specific charging cycle that the vehicle requires without delay. The system continually adapts to needs of the vehicle and the condition of the batteries at that moment in time.
MRG: So as I understand it, you sell more than just a wireless battery charging system. You’re selling a complete power solution that includes everything from the batteries to the charger.
Do you see a business opportunity to retrofit tuggers or other industrial trucks that use lead acid batteries with lithium ion batteries? Their batteries are going to have to be replaced at some point in the lifecycle of the vehicle.
Julian Seume: Currently, they do battery swaps on these types of vehicles, so that they can keep the vehicle in continuous production. That may happen twice a shift or it may happen every other shift. It requires someone to physically do the battery swaps and manage the charging cycles. This can be retrofitted with newer battery technology and these are the types of applications that we have stumbled into as we have deployed our solutions.
Initially, we never thought there would be a use case for industrial trucks. We thought it was AGVs and that’s what we designed for. But, we now see the opportunity for retrofits where we can deploy lithium batteries and wireless charging.
MRG: And now I see the other opportunity is when you’ve got so many different vehicle types and vendors in your facility that you can unify the charging solution. So you don’t have to have a specific charger platform for each of the different manufacturers, right?
Julian Seume: So that’s of course our goal as a startup to set the standard for this kind of inductive charging. And then I don’t care who manufactures it in the end. There will be one way how we transfer energy in 10 years and it’s going to be inductive. Right now, the difficult thing is explaining how it works and what the advantages can be. That’s our biggest problem. Once someone understands how it works and why it is better, they can see the advantages for their operation.
MRG: And then at some point this could be extended to electric automobiles on the road, right? If you’re stopping at a stoplight, why couldn’t your Tesla just connect wirelessly and say, “Hey, give me 30 seconds worth of charge” or let the system automatically charge for the length of the stop light?
Julian Seume: That’s the vision. We have to grow into the mobility market. But actually there’s one more thing that is over the top. This technology is bi-directional. So it means it can supply energy in both directions. We know how to do this, but we have not implemented it because there’s not really a use case in intralogistics. But if you go to the mobility market then it’s not only charging at a stoplight.
At some point it will be possible for electric vehicles to exchange energy while driving. Imagine a highway with swarm intelligence, driving autonomously. They could form up and drive close enough such that a vehicle with a high charge could share energy wirelessly to a vehicle that is running low on charge.
So, of course this is still in the far future but it’s just one example of what’s possible with inductive charging. And that’s why I’m so excited to be with the company, because I really think that it’s going to change how we are going to transfer energy in the future!