Car Parts Guide
BATTERY Mazda 6 · PARTS GUIDE

Mazda 6 Battery: Specs, Fitment & Common Faults

On the Mazda 6, leaving the car unlocked, even in your own garage, can genuinely drain the battery faster than keeping it locked.

Illustration of a 12V car battery Illustration for editorial purposes

OEM Part Number: KJ01-18-520B

Genuinely important to know, 2015-2017: models with i-ELOOP (Mazda's regenerative braking system) use a specific Q85-type battery that's genuinely different from standard variants — confirm whether your car has i-ELOOP before ordering.
Current/recent generations, genuine referenceMazda OEM: KJ01-18-520B (also referenced as KJ01-18-520A, 0000-80-0035-WB)
2009-2013, genuine referenceMazda OEM: 0001-80-6096-WB
2015-2017, with i-ELOOP, genuine referenceMazda OEM: PE1T-18-520 (also referenced as PE1T18520B, PE1X18520, PE1T18520A) — Q85 type, Japan-built

A Genuinely Distinctive, Real Behavioural Finding Worth Knowing — Mazda 6 Battery

Multiple documented cases on related Mazda models point to the car needing to be genuinely, fully locked to avoid faster-than-normal battery drain — even when parked inside your own garage. The suspected cause is the car continuously searching for and pinging a key fob left nearby while unlocked, which draws more power than when properly locked.

Worth knowing about a confirmed Mazda Special Service Program affecting related models: Mazda has officially acknowledged a Remote Tuner Module software fault on several 2023 models that can drain the battery if the car sits unused — worth asking a dealer whether this applies to your specific car and build date.

It's also worth knowing a genuinely useful technical benchmark: normal parasitic drain on a healthy Mazda while parked has been documented and calculated at around 55 milliamps, meaning a healthy battery should reasonably last around a month to six weeks before needing a recharge.

The Part Everyone Blames First, Not Always Correctly

A car that won't start gets blamed on the battery more often than any other component, and it's right often enough to make that assumption a reasonable first check. But it's not always the actual cause, which is worth knowing before spending money on a replacement that doesn't fix anything.

Mazda 6 Battery reference plate
Before you buy: battery size, capacity and type (standard vs AGM/EFB for stop-start systems) vary by trim and engine. Always confirm against your VIN before ordering.

What It Does

The 12V battery provides the power needed to start the engine and runs electrical systems when the engine isn't turning. On cars with stop-start technology, the battery works much harder than on older designs, since the engine switches off and restarts far more frequently — which is exactly why these cars need a specific AGM or EFB battery type rather than a standard unit.

Shop for This Part on eBay

Battery fits MAZDA MX5 1.5 1.6 1.8 2.0 048 340A 45Ah 4Yr Warranty New Battery fits MAZDA MX5 1.5 1.6 1.8 2.0 048 340A 45Ah 4Yr Warranty New GBP 48.28 Battery fits MAZDA 6 GG, GH, GJ, GY 2.0 2.0D 2.2D 249 780A 80Ah Quality Battery fits MAZDA 6 GG, GH, GJ, GY 2.0 2.0D 2.2D 249 780A 80Ah Quality GBP 69.18 Battery fits MAZDA MX5 1.5 1.6 1.8 2.0 Bosch 048 330A 45Ah 4Yr Warranty Battery fits MAZDA MX5 1.5 1.6 1.8 2.0 Bosch 048 330A 45Ah 4Yr Warranty GBP 57.53 EFB Car Battery fits MAZDA 6 GG, GH, GJ, GY 2.0D 2.2D Stop Start Bosch EFB Car Battery fits MAZDA 6 GG, GH, GJ, GY 2.0D 2.2D Stop Start Bosch GBP 118.70 AGM Battery fits MAZDA CX30 6 CX5 2.0 2.5 2.2D 2008 on Stop Start 027 AGM 680A AGM Battery fits MAZDA CX30 6 CX5 2.0 2.5 2.2D 2008 on Stop Start 027 AGM 680A GBP 72.23 Mazda 6 Battery Start Stop 80ah 12V Car Battery Mazda 6 Battery Start Stop 80ah 12V Car Battery GBP 51.66 AGM Battery fits MAZDA 6 GJ 2.2D 12 to 20 Stop Start 020 AGM 950A 105Ah Quality AGM Battery fits MAZDA 6 GJ 2.2D 12 to 20 Stop Start 020 AGM 950A 105Ah Quality GBP 145.30 Starter Battery 249 95Ah 780A CCA 12V T1 Terminal D31 For Mazda Mazda6 2.2 D AWD Starter Battery 249 95Ah 780A CCA 12V T1 Terminal D31 For Mazda Mazda6 2.2 D AWD GBP 113.59

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Warning Signs, DIY Difficulty & Aftermarket Advice

These are the same regardless of make or model — see our full Battery Guide for warning signs to watch for, confirming fitment against your VIN, and matching the right technology (standard, EFB, AGM) when buying aftermarket.

More Mazda Battery

The same part, covered across other Mazda models.