2015–2024 Subaru Outback

2015-2024 Subaru Outback — Battery Replacement

🔧 Easy 20-30 minutes $217 DIY

Save $72 by doing it yourself! Shop cost: $289

Quick answer: Battery Replacement on a 2015–2024 Subaru Outback is rated Easy and takes about 20-30 minutes. You'll need 4 tools for this job, and parts cost about $217. This guide walks you through the full job step by step, including the mistakes to avoid.

Quick Video Tutorial

Parts You Need

The options below are alternatives for the same part — you only need to buy one. Pick the one that matches your year and engine.

Part Name	Part Number	Price	Buy
12V Battery — Group 47/H5 EFB (2020-2024)	SOA821B900	$217.00	Amazon
12V Battery — Group 25 (2015-2019)	—	$160.00	Amazon

About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.

💡 Pro tip: Compare the options above and order the one that matches your vehicle — you only need one.

Step-by-Step Instructions

Follow these steps carefully

Park, shut down, and locate the battery

Park on a level surface, turn the engine fully off, remove the key or fob from the vehicle, and engage the parking brake. Open the hood and locate the battery in the engine bay.

Disconnect the negative (ground) terminal first

Using a 10mm wrench, loosen the nut on the black negative cable clamp. Twist and pull the clamp straight off the post. Tuck the cable aside so it cannot touch either terminal or any metal in the engine bay.

🔧 Mechanic's note — Tom Becker

If the clamp won't twist free, gently rock it side to side — never pry upward with a screwdriver, or you'll crack the post right off. I drape a towel over the tucked cable so it can't bounce back onto a terminal while I work.

Remove the terminal cover and disconnect the positive terminal

Lift off the red plastic cover over the positive terminal, then loosen its 10mm clamp nut with a wrench and remove the positive cable the same way. Keep both cables routed away from the battery.

Remove the battery hold-down

Unhook the battery cable holder from the battery rod, then remove the flange nuts on the hold-down rods and lift the battery holder bar off the battery.

Lift out the old battery and note the orientation

Carefully lift the battery straight up out of the tray. It is heavy, so lift with your legs. Before setting it down, note which side the positive post is on and the group size printed on the label.

Clean the tray and terminal clamps

Inspect the tray for corrosion and wipe or brush it clean. Clean the inside of the cable clamps with a wire brush so the new battery gets solid contact, then apply a thin coat of battery terminal grease to retard corrosion.

Choose the correct battery for your model year

2015-2019 Outbacks use a Group 25 battery. 2020-2024 Outbacks use a Group 47 (H5) battery in EFB chemistry, rated at 680 CCA, matching the factory specification. Match the new battery to your generation; the sizes are not interchangeable.

🔧 Mechanic's note — Ray Delgado

I've seen people buy a Group 47 that wasn't EFB for a 2020-2024 Outback — with start-stop, that battery dies in months. I check the label for EFB and 680 CCA, and photograph the group size on the old battery before going to the store.

Set the new battery in the tray

Lower the new battery into the tray in the exact same orientation as the old one, with the positive post aligned to the positive cable. Confirm it sits flat and flush on the tray.

Reinstall the hold-down and torque the rod nuts

Set the battery holder bar back on top of the battery and thread the hold-down rod nuts on. Torque the two holding-rod nuts to 3.5 N-m (2.6 ft-lb / 31 in-lb). The battery must not move in the tray.

Connect the positive terminal first, then the negative

Slide the positive clamp onto the positive post first and torque it to 6 N-m (4.4 ft-lb). Then connect the negative cable last and torque the terminal (and the battery sensor, if equipped) to 7.5 N-m (5.5 ft-lb). Replace the positive terminal cover.

🔧 Mechanic's note — Tom Becker

I've cracked posts by overtightening with a big ratchet — I use a small ratchet and snug it to spec. If the clamp spins on the post, the clamp is stretched, not too loose — squeezing it closed with pliers before tightening is the fix.

Let the throttle control relearn before starting

Turn the ignition to ON and wait at least 10 seconds before starting the engine. Subaru's service procedure calls for this pause so the electronic throttle control can perform its initial diagnosis after a battery swap.

Reinitialize the power windows and reset presets

For each window, turn the ignition ON, lower the window halfway, close it fully, hold the switch up about 1-2 seconds after it closes, then test auto operation. Reset the clock and radio presets, and return the old battery for recycling and your core charge.

All Done!

Test your repair before closing everything up. If something doesn't work right, double-check your steps.

⚠️ Common Mistakes to Avoid

• Buying the wrong group size for your generation: 2015-2019 Outbacks take Group 25, 2020-2024 take Group 47 (H5). The trays and cables are sized for one or the other.
• Putting a basic flooded battery in a 2020-2024 Outback that came with an EFB battery. These cars have auto start-stop and a charging strategy built around EFB; a cheap flooded replacement is likely to die early.
• Connecting the positive terminal last or disconnecting it first, risking a spark if the wrench touches ground.
• Forgetting to reinstall the battery hold-down bar, or leaving the rod nuts loose. An unsecured battery can shift, short against the hood, or spill.
• Replacing the battery a second time when the car keeps draining overnight without checking for the known parasitic draw. The DCM (Starlink telematics module) on 2021-2022 Outbacks is a documented cause of batteries dying repeatedly, even brand-new ones.
• Skipping the ignition-ON 10-second wait after install, which Subaru's procedure requires for the electronic throttle control's initial diagnosis.

Tools You'll Need

10mm socket or wrench (battery terminal clamp nuts) 10mm-12mm socket or wrench (battery hold-down rod nuts; carry both sizes) Ratchet with extension (hold-down rod nuts) Wire brush (terminal and tray cleaning) Battery terminal grease or anti-corrosion spray Safety glasses Gloves

⚠️ Safety First!

• Batteries produce explosive hydrogen gas. Work in a ventilated area, keep sparks, flames, and cigarettes away, and never lean over the battery while working.
• Battery acid is corrosive and toxic. Wear safety glasses and gloves. If acid contacts skin or clothing, rinse immediately; if it contacts eyes, flush with water for 15 minutes and get medical attention.
• Disconnect the negative cable first and connect it last. Never let a wrench bridge the positive terminal to any grounded metal — it will arc and can weld itself, damage the battery, or injure you.
• Remove rings, metal watchbands, and other metal jewelry before starting work.
• Batteries are heavy and can weigh over 40 pounds. Lift with your legs, not your back, and never carry one against your body.