27 August 2021
27 August 2021, Comments Comments Off on Knaus Tabbert shows its first electric motorhome at Caravan Salon 2021
Knaus Tabbert shows its first electric motorhome at Caravan Salon 2021

The first fully electric motorhome from Knaus Tabbert is being shown at the Caravan Salon 2021.

The “KNAUS E.POWER DRIVE” – its first fully electric motorhome produced, has been developed in cooperation with HWA AG – a leader in the motor sport and engineering field and an experienced, internationally renowned development partner.

The vehicle study “KNAUS E.POWER DRIVE” is based on a KNAUS Van Ti 650 MEG Vansation. Visually, it still resembles a conventional, partially integrated motorhome. But the complex technology of the KNAUS study can be seen in the cockpit. There is no need for a gear lever since you can dispense with the propulsion engine as well as the six-speed manual gearbox. In its place Knaus has installed “push button automatics” with a system known from automatic transmission: P (Park), R (Reverse), N (Neutral), D (Drive).

A further two buttons on the panel turn on the vehicle heating (also heats up the traction battery when outside temperatures are low) or turn off the recuperation during adverse driving conditions such as ice or packed snow. At the same time the six buttons show the charging status of the traction battery, which has a capacity of 35 kWh.

Also in the cockpit: The innovative HMI concept consisting of two large displays. The aim here was to develop the best possible solution for an optimum human-machine-interface. The 12 inch touch screen also enables you to manage the infotainment but can also display additional information about the driving mode. A second display shows the operating status of the motorhome, the speed or currently requested driving performance.

Even more was going on hidden away behind the bodywork. In place of the familiar diesel engine with transmission, an intelligent combination of electric motor and reduction gearbox comes into operation.

The e-motor performs at up to 180 kW and enables this fully equipped, four-seater motorhome to travel at over 110 km/h. It can, however, also recuperate during manual mode, meaning, it can produce electric energy which is stored in the high voltage battery installed close to the axis in the rear floor of the motorhome. At best, the lithium-ion cells of the front-wheel driven “KNAUS E.POWER DRIVE” can be recharged within around three hours at a public wallbox charging point. The Range Extender reduces the charging time to approx. 35 minutes.

The range of the “KNAUS E.POWER DRIVE”in purely electrical operation was determined at 90 kilometres in a WLTP test procedure. At the latest when the battery has reached its threshold level, but usually before then, the Range Extender starts up automatically during drive mode, which is coupled to a generator, eradicating the need for less convenient and time-consuming charging stops.

The REX’s main job is to charge the traction battery but it is also able to supply electricity directly to the drive motor. At the same time the REX also supplies energy to the living space of the recreational vehicle. The installed DC/AC converter (direct current/alternating current) provides the living space with normal household 230 volt and in doing so increases the self-sufficiency of the motorhome. 

The KNAUS Research specification sheet expressed its aspirations as follows: “During normal weather conditions it should be possible to live in the caravan independently for up to five days (lighting, cooking, heating).”

An essential component of the Range Extender is the state-of-the-art rotary engine, installed during the survey, which operates in the optimum rpm range and efficiently powers a flange- mounted generator. The benefits of this three-disk rotary piston engine from the KNAUS survey are clear: compact dimensions, easier assembly and less components than a reciprocating piston engine (no camshaft, no valves, no cam chain), smooth and quiet operation, can be used at an ideal rev range. But conventional combustion engines (petrol or diesel) are also an option, which drive the generator efficiently and with low emissions.

However, the long-term goal of Knaus Tabbert Research is to, in future, install a fuel cell in place of the rotary piston engine, which produces the required energy in an even more clean manner because it only emits water. The required hydrogen is then stored (crash-proof) in a special pressure tank instead of the conventional diesel tank.

In addition, in future, the vehicle will be “gas-free” and therefore exclusively operated in full electric mode, offering additional potential to save on weight. When the vehicle range is manufactured a variety of weight-saving measures will further optimise the weight balance. The aim of Knaus Tabbert Research and Development is to provide a basic motorhome in the popular 3.5 tonne class, approved for operation with four people, with a reasonable, useful vehicle load capacity.

Driving into designated green zones with the “KNAUS E.POWER DRIVE” will also be possible without restrictions in future. And so that other road users can hear the super-silent motorhome, Knaus has installed a sound generator for safety purposes, which produces a modern driving sound. With a full battery the vehicle can thus provide a very long period of self-sufficient, comfortable living when caravanning – even when there doesn’t happen to be an external charging point around.

The study presented on the KNAUS electric motorhome represents an awakening into a so far unknown freedom, flexibility and independence for modern caravanners – and that in a sustainable way – thus in harmony with an ecological responsibility for our environment.