The 2008 Scion xB uses a standard 12-volt automotive lead-acid battery.
In practice, replacement batteries for this model are commonly found in Group 51R formats, which are compact 12V units, but some early production runs or regional specs use Group 35. Check the label on your current battery or refer to the owner's manual to confirm the exact Group size. When shopping, look for a battery with suitable cold-cranking amps (CCA) and reserve capacity (RC) for your climate.
Battery size options for the 2008 Scion xB
Common replacement sizes you’ll see for the 2008 xB include the following:
- Group 51R — 12V lead-acid battery, compact size; fits most standard engine bays and provides adequate cold-cranking amps for most climates.
- Group 35 — larger footprint used by some Toyota/Scion models; may be required in colder climates or for upgraded electrical loads.
Remember: exact size depends on production date and regional variant. When replacing, ensure the battery fits your vehicle’s tray and terminals, and that the CCA meets or exceeds the OEM specification. If uncertain, consult a dealer or auto parts professional using your VIN.
How to confirm the correct battery
Check the current battery label
Look for the group size printed on the battery case (e.g., 51R or 35), along with CCA and RC ratings.
Use the owner's manual or VIN lookup
Refer to the manual or use a VIN-based parts lookup to identify the exact required battery specification for your trim and production date.
Maintenance considerations
Most 2008 xB batteries are 12V lead-acid flooded or maintenance-free units. If you experience frequent drains or hot-start issues, you may consider monitoring battery health or upgrading to a higher-CCA option suitable for your climate, while ensuring it physically fits the engine bay and terminal configuration.
Summary
For a 2008 Scion xB, you’re looking at a 12V automotive lead-acid battery. The most common replacement group sizes are Group 51R or Group 35, with the final choice depending on production date and climate. Always verify the exact specification via the battery label, the owner's manual, or VIN-based parts lookup to ensure a proper fit and reliable performance.