---
product_id: 406102328
title: "Rechargeable 3500mAh Lithium Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker"
brand: "rapthor"
price: "€ 96.05"
currency: EUR
in_stock: true
reviews_count: 5
category: "Rapthor"
url: https://www.desertcart.sk/products/406102328-rechargeable-3500mah-lithium-battery-compatible-with-harman-kardon-onyx-studio
store_origin: SK
region: Slovakia
---

# 3500mAh High Capacity Easy 10-min Installation Built-in Safety Circuit Rechargeable 3500mAh Lithium Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker

**Brand:** rapthor
**Price:** € 96.05
**Availability:** ✅ In Stock

## Summary

> 🔋 Power up your Onyx Studio and never miss a beat!

## Quick Answers

- **What is this?** Rechargeable 3500mAh Lithium Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker by rapthor
- **How much does it cost?** € 96.05 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sk](https://www.desertcart.sk/products/406102328-rechargeable-3500mah-lithium-battery-compatible-with-harman-kardon-onyx-studio)

## Best For

- rapthor enthusiasts

## Why This Product

- Trusted rapthor brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Safety First, Always:** Built-in protection circuit guards against overcharge, over-discharge, and short circuits.
- • **Plug & Play Simplicity:** Includes screwdriver and plastic tool for a hassle-free, under-10-minute swap.
- • **Seamless Compatibility:** Perfectly fits Harman Kardon Onyx Studio 1/2/3/4 models to revive your speaker’s portability.
- • **Power That Lasts Longer:** 3500mAh capacity outperforms the original battery for extended playtime.
- • **Engineered for Durability:** Foam cushion and sponge tape protect connectors, ensuring a reliable connection.

## Overview

The Rapthor Rechargeable 3500mAh Lithium Battery is a high-capacity, safe, and easy-to-install replacement designed specifically for Harman Kardon Onyx Studio 1 through 4 wireless Bluetooth speakers. It features enhanced durability with protective foam and sponge tape, a built-in safety circuit to prevent damage, and comes with all necessary tools for a quick upgrade, extending your speaker’s battery life and restoring its portability.

## Description

Rapthor 3500mAh 3.7V High Power Rechargeable Replacement Battery for Harman/Kardon Onyx Studio, Onyx Studio 2, Onyx Studio 3, Onyx Studio 4 Wireless Bluetooth Speaker Compatibility Rapthor replacement battery is compatible with Harman Kardon Onyx Studio, Onyx Studio 2, Onyx Studio 3, Onyx Studio 4. Higher Capacity 3500mAh high power replacement battery extend longer-lasting working time to your bluetooth speaker. Easy to Install Quick install within 10 minutes with included screwdriver and plastic tool. It’s quite simple. Considerate Details Foam strip for cushion absorbing, super long (longer than original’s) and durable battery wire for better connection, sponge tape well protects the connector wire from damage. Safe Performance Built-in protection circuit well protects the rechargeable battery from over-charge, over-discharge, short-circuit. Customer Service 30-day money back and 12-month warranty Specifications Battery Type: Li-ion Product Type: Replacement Battery Capacity: 3500mAh Voltage: 3.7V / 12.95Wh Package Included 1 x Rapthor Replacement Battery 1 x Screwdriver 1 x Plastic Install Tool 1 x User Manual

Review: Perfect for for my speaker - Perfect fit. My speaker is working again without the power cord. Watch YouTube videos for instructions on how to install.
Review: Onyx 4 Replacement - Overall, I am pleased. Let me first say that the directions included did not support the Onyx 4. However, this was a pretty easy battery swap. Back screws are under the grommets that hold the screen. Didn’t need the driver that came with it. Just use a standard small Phillips driver. Battery came charged. My speaker was back to normal in a few minutes. Keep in mind that this is a smaller battery than that of the original as far as physical size. However, even if it doesn’t last as long, which it may, I’m very happy with this battery. I missed my portability. No issues here so far.

## Features

- 3500mAh High Capacity Lithium Battery: higher capacity than the original battery, more durable performance.
- EASY TO USE - Simply install quickly with included screwdriver and plastic tool.
- CONSIDERATE DETAILS - Foam strip to absorb the cushion, durable and longer than the original battery cable for better connection, the sponge tape protects the connector cable well from damage.
- Safe Performance The built-in protection circuit protects the rechargeable battery well from overcharge, over discharge, short circuit.
- Compatibility: Compatible with Harman Kardon Onyx Studio, Onyx Studio 2, Onyx Studio 3, Onyx Studio 4.

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B099NJVQQ7 |
| Amperage | 3500 Milliamps |
| Best Sellers Rank | #69,509 in Electronics ( See Top 100 in Electronics ) #1,435 in Portable Bluetooth Speakers |
| Brand | rapthor |
| Built-In Media | Install tool, Replacement battery, Screwdriver |
| Color | black |
| Compatible Devices | Compatible with Harman Kardon Onyx Studio 1/2/3/4 |
| Compatible Phone Models | Compatible with Harman Kardon Onyx Studio 1/2/3/4 |
| Compatible Power Plug Type | No Plug |
| Compatible devices | Compatible with Harman Kardon Onyx Studio 1/2/3/4 |
| Compatible phone models | Compatible with Harman Kardon Onyx Studio 1/2/3/4 |
| Connectivity Technology | Bluetooth |
| Connector Type | Proprietary |
| Connector type | Proprietary |
| Current | DC |
| Current Rating | 3500 Milliamps |
| Customer Package Type | Standard Packaging |
| Customer Reviews | 4.5 out of 5 stars 313 Reviews |
| Enclosure Material | Lithium-ion |
| Included components | Install tool, Replacement battery, Screwdriver |
| Input Voltage | 3.7 Volts |
| Item Weight | 0.11 Kilograms |
| Manufacturer | MSW (Shenzhen) Technology Limited |
| Model Name | Replacement Battery |
| Number of Items | 1 |
| Number of Power Levels | 1 |
| Output Current | 3.5 Amps |
| Output Voltage | 3.7 Volts |
| Portable | Yes |
| Power Plug | No Plug |
| Power Source | Battery Powered |
| Special Features | Rechargeable |
| Special features | Rechargeable |
| Specification Met | Li-ion Battery Standard, Higher Capacity, Easy to Install, Safe Performance |
| UPC | 735818080479 |
| Unit Count | 1.0 Count |
| Voltage | 3.7 Volts |
| Wattage | 12.95 watts |
| Wired Charging Connector Type | USB Type A |

## Product Details

- **Brand:** rapthor
- **Colour:** black
- **Compatible devices:** Compatible with Harman Kardon Onyx Studio 1/2/3/4
- **Compatible phone models:** Compatible with Harman Kardon Onyx Studio 1/2/3/4
- **Connector type:** wireless
- **Included components:** Install tool, Replacement battery, Screwdriver
- **Input voltage:** 3.7 Volts
- **Number of Items:** 1
- **Special features:** Rechargeable
- **Wattage:** 12.95 watts

## Images

![Rechargeable 3500mAh Lithium Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker - Image 1](https://m.media-amazon.com/images/I/716QlRKgC-L.jpg)

## Questions & Answers

**Q: Any feedback after using it for a while?**
A: Sorry charged after it arrived and haven’t used it.  So I don’t know how long it holds a charge

## Customer Reviews

### ⭐⭐⭐⭐⭐ Perfect for for my speaker
*by H***O on 13 August 2025*

Perfect fit. My speaker is working again without the power cord. Watch YouTube videos for instructions on how to install.

### ⭐⭐⭐⭐⭐ Onyx 4 Replacement
*by M***B on 13 February 2024*

Overall, I am pleased. Let me first say that the directions included did not support the Onyx 4. However, this was a pretty easy battery swap. Back screws are under the grommets that hold the screen. Didn’t need the driver that came with it. Just use a standard small Phillips driver. Battery came charged. My speaker was back to normal in a few minutes. Keep in mind that this is a smaller battery than that of the original as far as physical size. However, even if it doesn’t last as long, which it may, I’m very happy with this battery. I missed my portability. No issues here so far.

### ⭐⭐⭐⭐⭐ Good replacement for the original battery!
*by Q***E on 9 March 2024*

My Harman/Kardon Onyx speaker is one of my favorites for rocking the bass while playing games or music. Yes, it is old now, but still worked great, except for one thing: the original battery no longer charged, so I was stuck with having to place the speaker near an AC source. Well, I finally got tired of that, so I looked for a replacement battery. This one got good reviews, had the necessary tools with it, was readily available, and was priced right. I'm listening to my wireless BT speaker right now, while I write this review. Very happy. If anything goes wrong, I'll let you know.

## Frequently Bought Together

- Rapthor 3500mAh Rechargeable Replacement Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker
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*Product available on Desertcart Slovakia*
*Store origin: SK*
*Last updated: 2026-09-01*