Parts for your 2021 Lexus Is-Batteries

2021 Lexus IS batteries — what they do and how to look after them

Based on Lexus technical references — including the 2021 Lexus IS Owner’s Manual, Lexus IS300h New Car Features and Repair Manual, and the Lexus Service and Warranty guides for AU/NZ — batteries are absolutely relevant to the 2021 Lexus IS range. Every model uses a 12‑volt auxiliary battery, and the IS300h hybrid additionally carries a high‑voltage traction battery for propulsion and regenerative braking.

In everyday driving, the 12‑volt unit powers the computers, lighting, infotainment, locks and, on non‑hybrid IS models, cranks the engine. In the IS300h, the 12‑volt battery “wakes up” the hybrid system and closes the high‑voltage relays