Anyone who drives an electric car always has one thing with them: plenty of electricity. Used for the drive, it is reserved for the vehicle itself and can hardly be used for other things such as bidirectional applications. Of course, USB ports and cigarette lighter sockets are also basically small sockets, but their 12 volts are poorly suited for larger consumers such as coffee machines or notebook chargers. But that can be changed, as the YouTube channel Batterista shows – from 200 euros and with a little tinkering. With a little more money, even quite professional.
Large Tesla battery recharges the small one
The basic idea is that every Tesla has a 12-volt supply battery on board, which is constantly being recharged by the drive battery – so you can use it intensively. This is where the YouTuber’s idea comes in: An inverter is connected to the small battery, which converts the available 12 volts direct current to 230 volts alternating current. That is the basis for operating larger consumers. The necessary steps are basically incredibly simple: Find the battery (in Model 3, for example, in the front of the Frunk under a simply clipped-in cover), loosen the plus and minus pole terminals, connect the inverter to it, done. Then it is ready for use and can, for example, provide electricity for the coffee machine shown in the video.
With the idea shown, it should be noted that the converters must be suitable for the devices to be operated. On the one hand there are so-called sine-wave converters, which provide a pure sine wave alternating current with 50 Hz; on the other hand, cheaper variants are available that only roughly pulse the alternating current. Such inverters are not suitable for sensitive power supplies. The pure sine converters are quite expensive, but another factor must be taken into account: their performance. Smaller devices create around 500 watts and are quite affordable. Larger ones with up to 1200 watts can quickly cost 1000 euros, but are then also extremely high quality and provide an absolutely pure sine wave.
The YouTubers use an interim solution that also delivers a sine wave, but relies on much simpler technology. The inverter they use comes from Novopal and costs around 350 euros. The connection to the 12 volt power source of the Tesla was implemented with two simple cable clamps. The two of them dismantled the paneling of the Frunks in the Model S.
However, the two Tesla drivers in the video commit a dangerous mistake: They do not install a fuse. This is a gross blunder, which in extreme cases could lead to a fire in the electric car. Flat fuses are common and have to be adapted to the cross-section of the cable. They secure the cables and prevent them from melting or fires. If there is a short circuit, only the fuse blows and nothing else happens.
In general, however, it should be noted that the 12-volt battery in the Tesla models is usually quite small. Maybe 40 Ah it will provide. Inverter manufacturers such as IBS (a quality supplier) state that inverters with almost 1200 watts require more than 100 Ah, at least when stationary. The reason: The original areas of application are in the camping area, where the vehicles are and the alternator (for combustion engines ) does not reload. The large capacity is intended to ensure that the inverter can be operated without problems for a certain period of time. The video on Youtube does not show how the small battery in the Tesla performs in the long term.
Cybertruck power for Cyberquad
Bidirectional applications are useful features, especially in electric vehicles. With the recently introduced MPDV electric car from Canoo, the possibility of connecting large consumers such as hammer drills is even aggressively advertised. The Tesla Cybertruck should also come with a powerful socket, even for charging the Cyberquad that is based on it. Tools are more demanding, however, because devices with motors sometimes require high starting currents in order to overcome the magnetic fields. The inverter therefore needs more power than the continuous demand of such consumers would suggest. However, this plays a subordinate role for pure heating consumers such as coffee machines.