Start with make, model, year — and key type
Car key fobs are not one battery per brand. The same make can need different cells by model year and by key style (smart / push-button vs remote / flip / keyed).
Use the car key fob battery finder for a US model year we have verified from the owner’s manual. If your year isn’t listed, we don’t invent a code.
Brand-wide rules are wrong
Toyota Camry smart keys and Toyota Corolla smart keys are not the same cell in every year — Corolla smart keys moved to CR2450 while Camry smart keys can still be CR2032.
Ford F-150 Intelligent Access switched from two CR2025 cells to one CR2450 across generations. Saying “F-150 = CR2450” without year and key type is how people buy the wrong pack.
What we publish — and what we don’t
Answers cite the OEM battery section for that key style. We only list years with an explicit CR (or equivalent) code in our sources.
This site covers the replaceable coin cell only — not key programming, cutting, shells, or immobilizer work.
Quick takeaway
Pick make → model → year → key type. Then buy the battery code page — not a “universal key fob battery” listing.