How to Install a 9-Volt Battery in a Boss Pedal: A Quick Guide

Updated at: 26/07/2025

Boss pedals, renowned for their robust build and iconic sounds, are often powered by 9-volt batteries. While generally reliable, these batteries eventually need replacing. Knowing how to efficiently swap out a depleted battery can save you valuable time and ensure you’re never caught unprepared mid-jam session. This seemingly simple task can be slightly confusing for the uninitiated, with variations in compartment access across different Boss pedal models. However, fear not! This guide simplifies the process, providing clear instructions and helpful tips to make the battery replacement quick and straightforward.

This concise, step-by-step guide will walk you through the process of installing a new 9-volt battery into your Boss pedal, regardless of the specific model. We'll cover everything from identifying the battery compartment to correctly inserting the new battery and securely closing the pedal. So, let's dive in and get your pedal back up and running in no time!

Preparation and Safety Guidelines

Tools Needed
Safety Guidelines
  • Always turn off the Boss pedal and disconnect it from any power source before opening it or handling the internal components. Failure to do so could result in electric shock.
  • Use the correct polarity (+ and -). Inserting the battery incorrectly can damage the pedal or cause it to malfunction. Double-check the battery compartment markings before installation.
  • Handle the battery carefully to avoid any leakage. Battery acid is corrosive. If any leakage occurs, clean the battery compartment immediately with a damp cloth and avoid contact with skin.

Step-by-Step Instructions

  1. Open the Battery Compartment

    • Unscrew the battery compartment on the front left of the pedal.
    • Completely remove the battery compartment cover.
    Completely remove the battery compartment cover.Completely remove the battery compartment cover.
    Open the Battery Compartment

  2. Locate Battery Compartment Components

    • Locate the spring, switch, and battery compartment inside.
    Locate the spring, switch, and battery compartment inside.
    Locate Battery Compartment Components

  3. Install the Battery

    • Insert the 9-volt battery into the compartment, ensuring correct polarity.
    Insert the 9-volt battery into the compartment, ensuring correct polarity.
    Install the Battery

  4. Close the Battery Compartment

    • Close the battery compartment.
    Close the battery compartment.
    Close the Battery Compartment

  5. Connect to Guitar and Amplifier

    • Plug the pedal into your guitar and amplifier.
    Plug the pedal into your guitar and amplifier.
    Connect to Guitar and Amplifier

Read more: Best Multi-Effects Pedals for Guitarists in 2017: A Comprehensive Review

Tips

  • Be careful not to lose any small parts during disassembly.
  • The pedal will only turn on when connected to a guitar.

Common Mistakes to Avoid

1. Incorrect Polarity

Reason: Connecting the battery with the positive (+) and negative (-) terminals reversed can damage the pedal's circuitry.
Solution: Double-check the battery's polarity markings against those inside the pedal's battery compartment before insertion.

2. Forcing the Battery

Reason: Trying to jam the battery into the compartment without aligning it properly can damage the battery contacts or the pedal's casing.
Solution: Ensure the battery is correctly aligned with the positive (+) and negative (-) terminals before gently sliding it into place.

3. Using the Wrong Battery Type

Reason: Using a battery with incorrect voltage (e.g., a 6V instead of a 9V) can lead to malfunction or damage to the pedal.
Solution: Always use a 9V battery specifically designed for use in electronic devices; check your pedal's manual for any specific battery recommendations.

FAQs

My Boss pedal doesn't seem to be working even after I've replaced the battery. What should I do?
First, double-check the battery's polarity (+ and -). Make sure it's correctly aligned within the compartment. If it still doesn't work, inspect the battery connection points for any corrosion or damage. If there's damage, you may need professional repair. Also check your power supply cable if your pedal uses one.