2015–2019 Subaru Outback

2015-2019 Subaru Outback - Battery

By Ray Delgado ✓ Certified Mechanic · Published Sep 21, 2026 · Updated Oct 22, 2026

🔧 Easy 20–30 minutes $140 DIY

Save $110 by doing it yourself! Shop cost: $250

Quick answer: Battery on a 2015–2019 Subaru Outback is rated Easy and takes about 20–30 minutes. You'll need 3 tools for this job, and parts cost about $140. This guide walks you through the full job step by step, including the mistakes to avoid.

Quick Video Tutorial

Parts You Need

Total Cost

$140.00

Part Name	Part Number	Price	Buy
Group-size battery (match your tray)	—	$140.00	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: Order all parts at once to save on shipping

Step-by-Step Instructions

Follow these steps carefully

Park it, shut everything down, and pop the hood

Park on a flat spot, set the parking brake, and switch the engine fully off — not accessory mode. Turn off headlights, blower, heated seats, and anything plugged into the 12-volt outlets. Pull the hood release inside the cabin and prop the hood open.

Find the battery on the passenger side of the engine bay

Before loosening anything, take a quick phone photo of the cable routing and terminal positions so you can put every clamp back exactly where it was.

Disconnect the negative terminal first

Fit a 10mm socket on the negative terminal nut and turn it counterclockwise until the clamp is loose enough to wiggle. Twist the cable end gently side to side and lift it straight off the post — never pry with a screwdriver, which can crack the post seal and start a leak. Tuck the loose cable down beside the battery where it cannot spring back onto the post. Leave the little sensor module attached to the cable end; it comes off with the cable and goes back on with it.

🔧 Mechanic's note — Ray Delgado

Leave that sensor module alone — it's molded into the negative cable and comes off with it. I've seen people try to unbolt it separately and snap the connector clean off.

Disconnect the positive terminal second

Flip up the red cover over the positive terminal and loosen its 10mm nut the same way. Keep both loose cable ends separated while you work.

Unbolt the hold-down and lift out the old battery

The hold-down bracket across the battery is secured by a long 10mm bolt, so use a socket extension to reach it without rounding the head. Lift the bracket off and set it where it cannot slide into the engine bay. Now grip the battery with both hands and lift it straight up, keeping it level the whole way — a car battery weighs around 40 pounds and the acid inside must stay upright. Set it on the ground off to the side, terminals facing up.

Clean the tray and terminals, then seat the new battery

Brush corrosion and debris off the battery tray and check it for cracks while it's exposed. Lower the new battery in the same orientation, matching the old battery's label for size and post positions so the cables and hold-down fit.

Reconnect positive first, negative last, then test

Slide the positive cable onto its post first and tighten the 10mm nut until the clamp can't twist by hand, then close the red cover. Start the engine and check strong cranking with no battery warning light staying on.

All Done!

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

⚠️ Common Mistakes to Avoid

• Disconnecting the positive terminal first or reconnecting it last — that order risks a short against the body; negative always comes off first and goes on last.
• Yanking the negative cable and damaging the small battery sensor module molded into it on these Outbacks.
• Buying a replacement without matching the old battery's label — post positions and case size must match or the cables and hold-down will not fit.
• Over-tightening the hold-down bolt and cracking the battery case.

Tools You'll Need

10mm socket Ratchet Socket extension (for the long hold-down bolt) Wire brush or battery terminal cleaner Work gloves Safety glasses Rag or shop towels Baking soda and water or terminal-cleaning spray (optional)

Related Trouble Codes

P0562 System Voltage Low

⚠️ Safety First!

• Wear gloves and safety glasses — battery acid burns skin and eyes.
• Never let a wrench touch the positive terminal and the vehicle body at the same time.
• Keep the battery level while carrying it; tipping it can spill acid.
• Work in a ventilated area and keep sparks, cigarettes, and open flame away — batteries give off explosive hydrogen gas.
• Remove rings, watches, and other metal jewelry before starting.