As well as Start-Stop and ICE vehicles, nearly all xEVs (BEV, PHEV, FCEV, Hybrids) require a 12 Volt power supply. 

Although these vehicles drivetrain may be powered by high-voltage Li-Ion batteries, a 12 volt system is still for comfort and critical safety features, not only while driving but also whilst parked. Safety features like lane assist, power steering and the brake booster are handled by onboard smart systems which also draws power from the 12V system. The same goes for most of the car's monitoring functions. 

Lead-acid batteries are favoured because they are known reliable and affordable technology. However, with any 12 Volt battery, there is a finite lifespan and once used, a replacement should be fitted. 

VARTA always recommend testing the 12 Volt battery of any vehicle when it enters a garage and the same applies to any type of xEV. VARTA offers the following testing advice: 

When it comes to testing on an xEV:
The battery cables for the High Voltage battery are all Orange in colour – Do not touch these.
The 12 Volt battery cables are standard and the same as ICE cars in size and colours.
The 12 Volt battery testing method is the same as a standard ICE vehicle, however on Full Hybrid & BEV cars, the alternator and starting tests cannot be carried out as there is no starter motor or alternator fitted. Charging is completed via the inverter / converter, and starting is achieved using a motor generator in the gearbox.
Ensure the battery tester you are using is capable of reading results from AGM, EFB AND sSLI batteries. 

VARTA also provides the following advice on the replacement process on xEV’s:
Ensure the vehicle ignition is completely switched off.
Remove the key and place it at least 2 metres away from the vehicle to prevent accidental ignition power up, of the smart entry / start system.
Use the VARTA Partner Portal to identify the vehicle and the location on board of the 12 Volt battery.
Disconnect the 12v battery as per manufacturers’ instructions (There may be a High Voltage ‘power-down’ waiting period).
When the 12 Volt battery is disconnected, the High Voltage side of the vehicle is also powered down and cannot be powered up again until the 12 Volt battery is installed.
The installation process is the reverse of the removal, the VARTA Partner Portal will be able to advise if recoding of systems or components is required.

Clarios is the number one supplier to all renowned Original Equipment Manufacturers with its VARTA brand with 60% of new vehicles in Europe being factory fitted with a VARTA, including Mercedes, Volkswagen and BMW. 

The VARTA team support garages and motor factors with face to face training, Battery E-Learning, which is now live in the VARTA Partner Portal which also has access to the Battery Finder, Fitting Instructions and Technical Articles

Customers can sign up for free at https://varta-partner-portal.com/