2017 Subaru Crosstrek Battery Size & Group

Quick Answer

• BCI Group Size: 25 or 35
• CCA Rating: 500-600 CCA recommended
• Reserve Capacity: 90-110 minutes
• AGM vs. Flooded: Either is acceptable, but consult your owner's manual or a Subaru specialist for specific recommendations if your vehicle has features like start-stop.
• Terminal Layout: Top post, standard (positive on the right when facing the battery with terminals closest to you)
• Physical Dimensions: (Group 25) 9.06" L x 6.81" W x 8.94" H; (Group 35) 9.06" L x 6.81" W x 8.86" H
• Dual-Battery Setup: Not applicable

Replacement Battery Options

Here are some popular replacement battery options. Always double-check fitment with the retailer:

• Interstate: MT5-25 (Group 25), MT5-35 (Group 35)
• Optima: YellowTop DS46B24R (fits some Subaru models, verify fitment for Crosstrek), RedTop 35
• DieHard: 38217 (Group 25 Platinum AGM), 38235 (Group 35 Platinum AGM)
• Odyssey: 25-PC1400 (Group 25), 35-PC1400 (Group 35)
• ACDelco: 25AGM (Group 25 AGM), 35AGM (Group 35 AGM)

AGM vs. Flooded — Which Does This Vehicle Need?

The 2017 Subaru Crosstrek typically came equipped with a standard flooded lead-acid battery from the factory. For most drivers, a high-quality flooded battery of the correct BCI group size and CCA rating will serve as an excellent replacement. These batteries are generally more affordable and have been the standard for decades.

However, if you're looking for enhanced performance, longer lifespan, or if your vehicle experiences frequent short trips, an Absorbent Glass Mat (AGM) battery can be a worthwhile upgrade. AGM batteries are sealed, maintenance-free, more resistant to vibration, and can handle deeper discharges better than flooded batteries. They also recharge faster. While not strictly "required" for a standard 2017 Crosstrek, an AGM battery is often recommended for its benefits and is perfectly compatible.

Always refer to your owner's manual for the manufacturer's specific recommendations, especially if your vehicle has any aftermarket electrical accessories or if you live in extreme climates.

Post-Installation Relearn / Reset Procedure

After disconnecting and reconnecting the battery in your 2017 Subaru Crosstrek, it's common for certain systems to lose their learned parameters. While there's no complex "relearn" procedure for the engine computer itself in most cases, you might notice some temporary changes that will resolve themselves with driving. Here's what to expect and what to do:

1. Idle Relearn: The engine idle might be slightly erratic or higher than usual immediately after battery reinstallation. Drive the vehicle for about 10-15 minutes, including some stops and starts. The engine control unit (ECU) will re-learn the proper idle parameters.
2. Window Auto Up/Down: The one-touch auto up/down feature for your power windows (especially the driver's) may need to be reset. To do this, roll the window all the way down, then press and hold the switch to roll it all the way up. Continue holding the switch for 2-3 seconds after the window is fully closed. Repeat for any other affected windows.
3. Radio Presets: Your radio presets will be lost and will need to be reprogrammed.
4. Clock: The clock display will need to be reset to the correct time.
5. Trip Odometers: Trip A and Trip B odometers will reset to zero.
6. Check Engine Light (CEL): In rare cases, a temporary check engine light might illuminate due to lost emissions monitor data. This should clear on its own after a few drive cycles, as the monitors complete their self-tests. If it persists, it may indicate another issue, or you may need to drive the vehicle more for the monitors to set.

No special tools are typically required for these minor resets on the 2017 Crosstrek. Drive the car normally, and the systems will adapt.

Signs of a Failing Battery

Don't wait until your Crosstrek won't start to replace your battery. Be aware of these common signs of a dying battery:

• Slow Engine Crank: The most obvious sign. The engine turns over slowly or with difficulty when you try to start it.
• Dim Headlights/Interior Lights: Especially noticeable when the engine is off or just starting.
• Battery Warning Light: If your dashboard battery light illuminates, it could indicate an issue with the battery or the charging system.
• Corrosion: Excessive corrosion around the battery terminals can impede current flow.
• Swollen Battery Case: A bulging or cracked battery case is a clear sign of internal damage and requires immediate replacement.
• Frequent Jumps: If you find yourself needing to jump-start your car often, it's time for a new battery.
• Age: Batteries typically last 3-5 years. If yours is older, it's living on borrowed time.

Common Battery Issues for This Generation

The 2017 Subaru Crosstrek, like many vehicles in its class, generally has a reliable electrical system. However, specific issues related to the battery itself or its performance can arise:

• Premature Failure in Extreme Climates: Batteries, especially flooded ones, can degrade faster in very hot or very cold climates. Heat accelerates fluid evaporation, while cold reduces cranking power.
• Parasitic Draws: While not unique to the Crosstrek, an aftermarket accessory or a persistent electrical fault can slowly drain the battery even when the car is off, leading to unexpected dead batteries. This is often harder to diagnose.
• Start-Stop System Strain (if equipped): Although less common on the 2017 model, if your Crosstrek were equipped with a start-stop system (common in later generations), these systems put added strain on the battery. Using a standard flooded battery in a start-stop vehicle not designed for it can lead to premature failure.

Regular battery testing, especially as your battery ages, can help you avoid being stranded.

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