2018 Subaru Crosstrek Battery Size & Group

Quick Answer

Here’s a quick rundown of the 2018 Subaru Crosstrek battery specifications:

• BCI Group Size: 25 or 35
• CCA Rating: 550–640 CCA (minimum recommended)
• Reserve Capacity: 90–100 minutes
• AGM vs. Flooded: Either is acceptable, but AGM is generally recommended for its longevity and performance benefits, especially with modern vehicle electronics.
• Terminal Layout: Top Post; usually B with positive on the left when facing the battery.
• Physical Dimensions: Approximately 9.06" L x 6.89" W x 8.86" H (varies slightly by group size and manufacturer)
• Dual-Battery Setup: Not applicable; the 2018 Subaru Crosstrek uses a single 12V starting battery.

Replacement Battery Options

When it's time to replace the battery in your 2018 Subaru Crosstrek, you have a variety of excellent choices. Here are some popular options, keeping in mind that part numbers can vary by retailer and specific model:

• Interstate: MT-25 (Flooded), MTZ-35 (AGM) or MTZ-25 (AGM)
• Optima: YellowTop DS46B24R (Group 35, often fits with minor modifications for height) or RedTop 35
• DieHard: Platinum AGM Group 35 or Gold Group 35 (Flooded)
• Odyssey: 35-PC1400 (AGM)
• ACDelco: 35AGM (AGM) or 35P (Flooded)

Always double-check the BCI group size and terminal layout against your existing battery and vehicle specifications before purchasing.

AGM vs. Flooded — Which Does This Vehicle Need?

The 2018 Subaru Crosstrek can utilize either an Absorbed Glass Mat (AGM) or a traditional flooded lead-acid battery. Both will work, but there are distinct advantages to choosing an AGM battery.

Flooded batteries are the more conventional and often more affordable choice. They have been the standard for decades and provide reliable starting power.

AGM batteries, while typically more expensive, offer several benefits: they are maintenance-free, more resistant to vibration, have a slower self-discharge rate, and are less prone to sulfation. Crucially, AGM batteries are better suited to handle the demands of modern vehicles equipped with more sophisticated electronics and start-stop systems (though the 2018 Crosstrek does not have a conventional start-stop system, it still benefits from the higher electrical load capacity of an AGM). Their ability to deliver consistent power over a longer period and withstand repeated deep discharges makes them an excellent upgrade for your Crosstrek.

Post-Installation Relearn / Reset Procedure

After replacing the battery in your 2018 Subaru Crosstrek, it’s a good idea to perform a basic relearn or reset procedure to ensure all systems are functioning optimally. While not always strictly necessary for basic operation, it can help prevent minor drivability issues or warning lights.

1. Idle Relearn: After connecting the new battery, start the vehicle and let it idle for 10-15 minutes without touching the accelerator. This allows the Engine Control Unit (ECU) to relearn the idle parameters.
2. Window Auto Up/Down: The one-touch auto up/down feature for the windows may need to be reset. For each window, fully lower it, then fully raise it and hold the button for an additional 2-3 seconds after it's closed.
3. Radio Presets: You will need to reprogram your radio stations and clock settings.
4. Steering Angle Sensor (if applicable): While less common on a full battery disconnect, some vehicles may require a steering angle sensor reset if traction control lights illuminate. This often involves driving the vehicle straight for a short distance at a low speed.

If you experience any persistent warning lights or unusual behavior, it's best to consult your owner's manual or a qualified technician.

Signs of a Failing Battery

Catching a failing battery early can save you from being stranded. Here are some common indicators that your 2018 Subaru Crosstrek’s battery might be on its way out:

• Slow Cranking: The engine turns over sluggishly when you try to start the car.
• Dim Headlights or Interior Lights: Especially noticeable when the engine isn't running.
• Warning Lights: A battery warning light on your dashboard.
• Corrosion: Visible white or blue powdery residue around the battery terminals.
• Swollen Battery Case: A bulging or cracked battery case can indicate internal damage or overcharging.
• Electrical Issues: Problems with power windows, radio, or other electronic accessories.
• Frequent Jumps: Needing to jump-start your vehicle regularly.

Common Battery Issues for This Generation

While the 2018 Subaru Crosstrek generally has a reliable electrical system, a few common battery-related issues or considerations are worth noting for this generation:

• Parasitic Draws: Aftermarket accessories or sometimes even factory components can create a "parasitic draw," slowly draining the battery when the vehicle is off. If your battery dies prematurely, especially after sitting for a few days, investigate potential draws.
• Short Trips: Frequent short trips where the engine doesn't run long enough to fully recharge the battery can lead to premature battery wear. This is a common issue in many vehicles, not just the Crosstrek.
• Cold Weather Performance: As with all batteries, extreme cold can significantly reduce performance. Ensure your battery is properly sized and in good health before winter hits.
• OEM Battery Lifespan: While some factory batteries last longer, many original equipment batteries provide around 3-5 years of service. If your Crosstrek is nearing or past this age, consider proactive replacement.

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