2018 Subaru Outback Battery Size & Specs

Quick answer

• BCI Group Size: Group 25
• Cold Cranking Amps (CCA): 355-390 A
• Reserve Capacity (RC): 90 minutes
• AGM vs Flooded: Flooded (standard); AGM (optional upgrade)
• Terminal Layout: Left-hand positive
• Physical Dimensions (approximate): 9.1 in. L x 6.9 in. W x 8.9 in. H

Replacement battery options

• Interstate: MT-25
• DieHard: Gold 25
• ACDelco: Gold 25
• Optima: YellowTop DH6

AGM vs flooded — which does this vehicle need?

The 2018 Subaru Outback comes standard with a conventional flooded lead-acid battery. This is a reliable and cost-effective option that will perform well for several years. However, for drivers in extreme climates or for those who make many short trips, an Absorbed Glass Mat (AGM) battery can be a worthwhile upgrade. AGM batteries are more resistant to vibration, have a lower self-discharge rate, and perform better in cold weather. They are also spill-proof, making them a safer option. While an AGM battery is not required for the 2018 Subaru Outback, it is a recommended upgrade for improved performance and longevity.

Post-installation relearn / reset procedure

After replacing the battery in your 2018 Subaru Outback, you may need to perform a relearn procedure to ensure all systems are functioning correctly. The most common issue is with the power windows. To reset them, simply roll each window down and then up again, holding the switch in the "up" position for a few seconds after the window is fully closed. You may also need to reset the clock and any saved radio presets. In some cases, the vehicle may need to be driven for a short period for the engine computer to relearn its settings.

Signs of a failing battery

• Slow engine crank: If the engine turns over more slowly than usual when you try to start it, this is a classic sign of a weak battery.
• Dimming lights: If the headlights or interior lights dim when you start the car or when you are using other accessories, the battery may not be able to provide enough power.
• Warning light: The battery warning light on the dashboard may illuminate if the battery is failing or if there is a problem with the charging system.
• Corrosion: If you see a white, powdery substance on the battery terminals, this is a sign of corrosion, which can interfere with the flow of electricity.

Common battery issues for this generation

The 2015-2019 generation of the Subaru Outback is known for a parasitic drain issue that can cause the battery to die prematurely. This is often caused by a faulty DCM (Data Communication Module). If you are experiencing frequent dead batteries, it is a good idea to have your vehicle checked for this issue. Additionally, the original equipment battery that comes with the Outback is often criticized for being undersized and not lasting as long as it should. Upgrading to a higher-quality AGM battery can help to mitigate this issue.

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