I have today.New Yuasa 12V Aux battery fitted by me. My 2015 Lexus CT200h Aux battery was flakey, I needed a jump start from a friend. Just enough to boot the computers to start the car. The aux battery is charged from the Hybrid battery via a DC to DC buck converter ie 210V DC to approx 14.5V DC to charge the aux battery. I added a direct connection to my new Aux battery, to be able to charge in car downtime, using NOCO Genious 2 charger. A NOCO spade connector adaptor connected directly to my new aux battery. I can now easily connect my NOCO Genius 2 charger directly to the aux battery. I find owning a car without an alternator and starter motor a new experience. I have now read up on hybrid cars and how they work. Very interesting.