2021 Subaru Forester: battery drain or dead battery

6 of the 215 complaints about the 2021 Subaru Forester describe battery drain or dead battery.

owner complaints: 6
of this car's complaints: 3%
recalls: 0

Is there a fix? 152 service bulletins cover this area of the car. See below

Battery drain or dead battery by model year

2022
1
2021
6
2020
26
2019
29
2018
27
2017
30
2016
19
2015
8
2014
1
1998
1

What owners say

Filed Jun 17, 2026 · Electrical · NY

Persistent Battery Drain on a 2021 Subaru Forester Limited. Problems began in year 4 of ownership (~17,000 mileage), after Subaru Starlink Subscription services expired. Red (Error) Starlink SOS indicator light was evident, where a normal light would show green. Battery would fully drain after about 3-4 days of inactivity while parked in a commercial garage. After repeated dead batteries, a jump-starter battery pack was used regularly, as well as a wall-outlet battery charger. The problem has not resolved with a new and appropriately specified AGM battery, replaced in December 2025. The only solution is to pull the engine-bay fuse #5, which disables the Data Communication Module (DCM), as well as other features (hands-free microphones and audio system). By pulling the fuse #5 consistently, the problem has ceased, even after a two-week period of no use. This provides irrefutable evidence that the DCM powered by fuse #5 is the source of the battery drain. The only resolution Subaru would offer was to insist on a dedicated diagnostic visit to a dealership, with the associated costs of hundreds of dollars to be borne by me, the customer, without a clear understanding of the costs or remedies to resolve this problem. I feel unsafe driving my vehicle for more than short trips given the risk of stranding or further electrical malfunctions that would impact critical vehicle functions or safety systems.

Filed Jun 3, 2026 · Electrical · FL

2021 Subaru Forester The vehicle has experienced recurring electrical and battery-related issues for several years. The original battery was replaced by the Subaru dealer with a larger-capacity battery because of repeated starting concerns. The replacement provided only temporary improvement. The vehicle continues to experience rough starting on a regular basis, even after installation of a newer aftermarket battery with a higher cold-cranking-amp rating. The current battery is approximately five months old. The most significant safety concern occurs during Auto Start-Stop operation. On multiple occasions, the engine has shut off at a stop as intended, but then failed to restart when attempting to move again. When this occurs, multiple warning lights illuminate on the dashboard and the vehicle is unable to proceed until it is shifted into Park and restarted manually. Because of this issue, I now disable the Auto Start-Stop feature on every drive to avoid a potential failure to restart while in traffic. The issue has been ongoing for years and has occurred with multiple batteries, including the dealer-installed replacement battery and a newer aftermarket battery. The dealer suggested that an aftermarket dash camera could be contributing to battery drain. The dash camera was disconnected, but the problem continued. I am concerned that failure of the vehicle to restart after Auto Start-Stop operation could leave the vehicle disabled in traffic and create a safety hazard. The condition appears to involve the vehicle’s electrical system, battery management system, charging system, Auto Start-Stop system, or a combination of those components. The vehicle is available for inspection upon request.

Filed Dec 1, 2021 · Electrical · AZ

Several instances of parasitic drain of the battery resulting in vehicle not being able to be started without a jump. Nothing was left on in the vehicle. Each time it was parked with the alarm set for approx 3-4 hours. The battery was completely dead. This vehicle is only 8 months old and this has happened around 8-9 times. Dealer does nothing about it except to charge the battery. This is unacceptable.

Filed Aug 15, 2021 · Electrical · CA

The batteries drained overnight 3 times within 7 months after the purchase of the new vehicle. Battery was jumped each time by Subaru Roadside Assistant. The dealer checked the battery and it was fine. It is the electrical (CAN) problem that drained the battery.

Filed Jul 25, 2021 · Electrical · ID

I parked in the parking lot yesterday afternoon. But when I try to start my car this morning, the battery dead！I just bought this new Subaru three months with 5000 miles. Very disappointed.

Filed Feb 7, 2021 · Electrical · 6,252 miles · NY

The car is two months old and the battery died (nothing was left on)!