Key locking AUDI A6 Avant (4B5, C5)

For the key locking battery in an Audi A6 Avant (4B5, C5), the typical car battery specifications depend on the engine variant, but common characteristics for the main battery include:

- Voltage: 12V
- Capacity: Around 70-80 Ah (Ampere-hours)
- Cold Cranking Amps (CCA): About 640-760 A
- Size: 278-315 mm length, 175 mm width, 190 mm height
- Battery type: Lead-acid, AGM, or EFB depending on model and year
- Hold-down type: B13 is common

Brands like RIDEX, BOSCH, EXIDE, VARTA, and Continental are known to supply suitable batteries for this model.

If you mean the small battery inside the key fob (for keyless locking), that is usually a button cell battery, most likely a CR2032 or similar.

If you want the exact battery needed for the car itself or the key fob, please specify which battery you're referring to: the main car battery or the key fob battery.

For the main car battery, a common example for a 2.5 TDI engine Audi A6 C5 Avant is:

- Capacity: 75-80 Ah
- Cold Cranking Amps: 680-760 A
- Size: 278x175x190 mm
- Voltage: 12V
- Hold-down type: B13

For the key fob battery, check the key fob case for the button cell type (often CR2032).