Carver is a manufacturer of smart mobility for three-wheel vehicles. It is headquartered in Netherland. It was founded in 1994. It is located in Leeuwarden, Netherland. The key people in the company are Anton Rosier (CEO), Chris Van den Brink (CTO), and Harry Kroonen (Engineer).
The company is focused mainly on one person or one plus one person.
An interview was conducted by the TU Delft, with Chris Van den Brink. It has been edited as per the required need. Read about his perspective on an electric vehicle.
From the perspective of technology and as an electric vehicle manufacturer, what makes an electric vehicle better than a fossil fuel-powered vehicle?
Very good question I think in the future we should all drive electric and the main reason is that we got a big CO2 problem. We take oil out of the ground and burn it and it will take us back to the dinosaurs’ age when we got too much co2 in the air. So if you want to save the world we have to drive electric because with electric you can use any source of energy. You can use water energy, power energy, you can use windmills, can use solar panels and we even can do everything.
Reasons to buy an EV?
Now I mean electric is the future. It’s not that we have to go a step down it’s a step up the driving behaviour. You get a lot of torque so it’s very comfortable to drive you don’t have to shift it’s very compact so it’s the way for the future.
The decision to make the Carver a fully electric vehicle rather than a plug-in hybrid?
The basic idea with this car concept is that we wanted to make a city vehicle which, what, price concern is between a scooter and a car so. And because it’s very aero-dynamical so we need not as much energy to propel it. So with a quite small battery pack, we can already achieve two and a half hours of driving with this vehicle. And that’s for one day more than enough for the use
Which parts of the electric car have huge potential for improvement, both technology-wise and cost-wise?
Of course, the batteries, I mean, for the electric vehicle is the most expensive part of the vehicle, and had to make it for large volumes you need to bring the price down as much as possible. So that’s why I think that electric vehicles should be very light, it should be very aero-dynamical because yeah, the battery is the most expensive part of the vehicle.
Compared to a conventional car, which parts of an electric car are maintenance-free, and which parts still require maintenance?
Almost everything is maintenance-free apart from the brakes, okay we still break with regen so we use fewer brake pads but eventually the brakes wear out. And second the tires they wear down as quickly as normal so it’s brakes and tire. And all the other things, I think so, are maintenance-free.
With the increasing availability of charging infrastructure, is a long-range EV with a big battery needed?
Well you see more and quicker charging, to be honest for a normal vehicle, this is a city vehicle it’s low-speed but for normal high-speed vehicles depends on how fast you charge
Would we see the AC onboard charger of EVs being completely moved out, like what we see in laptops?
Well, to be flexible I think you both need the DC fast charger and AC slow charger, for instance at my house there is no charging station so I have to do with the AC charger.
Technical advantages and disadvantages of a Carver compared to a conventional family electric car and compared to the other two-seater electric vehicles?
It is the way around the main reason why we see a lot of four-wheelers and drive four-wheelers is they don’t use this tilting technology. With the carver, we can make a very narrow vehicle. If you normally would make the four-wheel not tilting vehicle and if you take a corner too fast you will flip over to the outside. Because of this invention which we use in the Carver through the automatic tilting system it tilts like a motorbike, it drives like a car and that makes a very stable concept even when you make a corner very fast that’s why we can make a vehicle less than one meter wide.
I’ll start with the advantages. Personally, my biggest advantage is that so much fun to drive but that was not the reason why we developed it. We developed it because we’re going to have an aero-dynamical footprint of one person wide. We specifically developed this for one or two persons but they are sitting behind each other so there’s a very less aero-dynamical drag. But then I come to the disadvantage: if you are with four persons, you should take a normal car which is suitable for four persons if you drive alone or with two, you should take this type of vehicle…yeah.
Range anxiety in Carver users. Target customer base and reasons to pick Carver over competitors?
Yes I know but as I already explained, this is a city vehicle which has a top speed just below 50 kilometers an hour so if you take Carver, you take something which is in reach, drive two hours and that’s a long time so you will not take Carver if you want to go from here to Amsterdam but you can take it, you’ll take a Carver if you go from here to Rotterdam them so yes and no. It depends on which kind of vehicle you compare it with. If you are four people, you have one family you got a budget of only buying one vehicle, and that people will buy a four-person vehicle. Specifically our target to people who are living alone or two o to be more flexible. You see a lot of people already have got a car for holidays and long distances and cities, they use Carver.
Design and safety?
Yeah, it’s not a car, it’s not a motorbike. The safety, we’ve got a very safe rollover cage that protects the person and gives you the maximum protection you don’t need to have and wear a helmet because all safety belts are tested. Again this is a 50-kilometer power vehicle that’s a different kind of standard and if you compare it with the machines with high-speed 200 kilometres an hour vehicles so it’s yeah you have to see the perspective.
Selection of the motor in the carver and the reasoning?
We use the wheel head motor which is inside the wheel and you can see these shaft bits each on the suspension this can turn and the rim is directly mounted on the motor. We use this kind of package because we wanted to place between the wheels our battery pack, low center of gravity, and then the wheel motors two of these, one on the left and one on the right.
Reasons for Li-Ion batteries and the type of cells?
We use Li-Phosphor cells. We use 16 of these. We chose this type of battery because basically, this is very reliable and safe, so it does not get punctured and catch fire which very important issue because we want this to be as safe as possible. Secondly and these kinds of cells were very easy to package, 16 so two rows of 8 cells in combination with our battery management system on top of it. So this is why we chose this kind of battery. They are cubes-wise so you can easily pack them.
Carver’s strategy to ensure battery longevity
We do both. We dump and do not take out 100% of the battery and we keep a big amount, we use less than maximum capacity. First of all, to ensure the lifecycle is, it’s good for the lifecycle. Second, as the battery is getting old, the maximum amount of energy starts getting less and less and less. So we start already with less, then battery capacity is getting less, and the range capacity will not kick in, because we cover a certain amount over in the beginning. So when a customer thinks, “Okay, I can always drive to work” and even when the car could be three years old, he can still have the same range, and not in the beginning too much and when the battery is getting older, the range is getting less and less and less.
Cooling of batteries in Carver is done. It also has to do with our legislation on the vehicle. We are only allowed to take two kilowatts of the motor. So we don’t need to cool the batteries.
What are possible battery chemistries being considered for future EVs and why?
We keep our eyes open. It’s always a combination of prices the availability because not everybody is willing to deliver your batteries and how it’s easily packaged in the vehicle. So a lot of reasons why we choose a specific type of battery.
Technological challenges when moving from a single cell to an EV battery pack?
That’s a good question single-cell is quite simple because you charge me so you know which kind of cut-off voltage you have to get out. Lithium cells are different, from lead acid batteries when you charge them and they tend that the voltage of both the cells get higher or lower with old school lead, the efficiency, and the charging but they all end up having the same State of Charge. With Lithium, you have to be careful and that’s why you have to use a battery management system, which measures the voltage of every cell individually and takes a look at them. See, “that one is too full, so we have to empty that one a little bit. That one is a bit too empty, so we have to charge that one up”.
How long does it take to charge the battery, ways to reduce the charging time, the lifecycle of the battery, and maintenance is needed?
Around four and a half five hours. Yeah, with the Carver we don’t have that quick charge so we have no DC charging. We wanted to make it as simple as possible it’s just like a vacuum cleaner you can put it into any socket. So if you want to increase the charging speed, or decrease the charging time we have to introduce the DC charger. It is at the moment 4000 cycles and that’s a long time and that’s what our manufacturer and supplier are guaranteeing us. But we have not reached that point at this moment you as you calculate four thousand times…it’s 4,000 days of riding.
Source:- Electric Cars: Technology