The ground-breaking Porsche Taycan seems to have hit a small road bump in its success story after the US National Highway Traffic Safety Administration (NHTSA) recently received complaints from owners, prompting further investigation. The governing body has received nine complaints regarding “a loss of motive power while in motion at any speed without warning to the driver”, which depending on the gravity of the problem – could spell a recall for the Taycan in the US market.
For now, at least, the complaints seem to be isolated to the US market, where Porsche has delivered over 6,500 units and counting, approximately half of the 12,000 odd units believed to be delivered worldwide between 2020 and 2021, according to MotorBiscuit. However, seeing as how all Porsche Taycans are produced at Porsche’s new cutting edge facility in Zuffenhausen – where it assembles the body, electric-motor(s), transmission and drive axles before final assembly – suggesting that it might be a problem that could afflict more than just the US market cars.
While both the NHTSA and Porsche are understandably tight-lipped over the issue, AutoNews reports that cars suddenly losing power could be caused by the 12V lithium-ion phosphate (LiFePO) battery in the Taycan. According to them, Porsche still uses a 12V battery in the Taycan for greater parts commonality with other models and to power common systems of the car such as the door locks and interior lighting which doesn’t require power from the car’s main 800 Volt battery system that drives the car.
Due to the Taycan’s complex recharging and energy recuperation system, the 12V battery is understood to be also charged while the main 800V battery is topped up, however, if the 12V battery is drained or isn’t charged as intended, the central control systems of the car shut down or lose power, thus rendering the car undrivable.
A cursory look at the TaycanForum page also turns up a number of posts where Taycan owners have not been able to open their vehicles because the car’s security system will not work. Even if they manage to use the physical keys to open up the car, the car's main functions such as the instrument cluster and electronic gear selector will not work.
Image credit: Taycan Forum
One comprehensively written post by a Taycan owner (in the US) describes a similar problem, which was solved when the Porsche engineer managed to get the 12V battery charged up, allowing the car’s major control systems to fire up and bring the car back to life.
Image credit: Taycan Forum
Problems with 12V batteries shutting off the control systems of EVs are not something new, and afflict other EVs too such as Teslas according to certain forums. For now at least, it’s pretty certain that Porsche will be trying to understand the issue which could be isolated to just the 12V batteries, the power electronics that decide what to charge when or even the software then controls the hardware in the Taycan.