Ultracapacitors

A few weeks ago Motoring Weekly wrote an article about Lynk & Co and the Compact Modular Architecture that they were using in conjunction with their parent Volvo under the Geely group ownership. One of the components in that architecture has been provided by Maxwell Technologies: ultracapacitor modules.

Maxwell have been supplying battery and electrical equipment for years, however they have been typically embedded in another set of components. Earlier this year, Maxwell signed a deal with Geely – their first direct deal with a car manufacturer and this was important for Maxwell as it meant that they have taken a big step forward in their business.

What is an Ultracapacitor?
They are some times called supercapacitors and are another form of energy storage. They are able to recharge and hold more power volume than a rechargeable battery and importantly, they can take many more cycles than a battery can. Like the classic car battery that has risen to 48-volts and are now being fitted to many high-end vehicles, and like rechargeable batteries that are improving in leaps and bounds for extra vehicle range, ultracapacitors are also now in a fast evolution for more usage.

The origin of the capacitor goes back to the 18th century when European scientists figured out how to hold an electric charge for later use and they used a wide variety of materials – both for the conducting and insulation parts of the unit. The technology is now getting faster and more powerful with each year passing and one important area that they are now being used in is stop-start functions for petrol or diesel powered vehicles. Normal lead-acid batteries take a big hit when this function is used in traffic and I have read reports that suggest that this type of battery could be worn out in under two years if used regularly. Some 12-volt batteries fitted in the factories are also only lasting this long – in normal usage without stop-start functions. An ultracapacitor can last up to ten years (with today’s designs) and cope with 250,000 or more starts.

Maxwell Technologies
This is a company that not many people would know about even though they have been around to fifty years – especially as their technology is embedded in someone else’s kit. Over six million cars already use Maxwell’s ultracapacitors in some form. They are typically used in hybrid cars to provide a sudden boost when the vehicle switches from electric power to petrol power. This can be done by holding a bigger charge in the ultracapacitor to fire the motor and keep the vehicle moving safely. This is the first implementation in the Geely architecture with a group of ultracapacitors connected to a power conversion board that provides enough power to get the internal combustion engine into a spin and ignition cycle.

What Maxwell have now achieved is to “black box” their systems so that they can be plugged into the architecture that underpins the Volvo and Lynk & Co vehicles. That means designing and building all the circuit boards, software, casings etc, so that when it reaches the production line, it can be installed quickly. This is something that now puts them in direct competition with others such as Continental in Europe, however by signing the agreement with Geely, they have tapped a very large vehicle manufacturer and as such their technology is likely to spread further through that group.

The Geely group is focused on hybrid and full electric cars for their future and they have realised that the way to reduce rolling emissions is to have systems that use less fuel. With ultracapacitors, more power can be stored than batteries and can be charged quicker. This means that a combination of battery and capacitor could well extend the range of electric vehicles – and hybrids for those drivers who want a boost of power from a smaller motor. They recognise that even the Lithium-ion battery has limitations and currently, to get more power or more range, you need a bigger battery. Vehicle manufacturers are focused on lightweight designs to reduce power consumption. This is where ultracapacitors can help – they are lighter and rapidly becoming much more powerful. Geely and Maxwell have come up with a system that utilises both technologies, however I would expect that the rechargeable battery will also be gone within a couple of decades as development continues on with ultracapacitors.

Maxwell Technologies are now at the forefront of this evolution.