--- product_id: 406102328 title: "Rechargeable 3500mAh Lithium Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker" brand: "rapthor" price: "€ 137.40" currency: EUR in_stock: true reviews_count: 5 url: https://www.desertcart.gr/products/406102328-rechargeable-3500mah-lithium-battery-compatible-with-harman-kardon-onyx-studio store_origin: GR region: Greece --- # 3500mAh High Capacity Easy 10-min Install Kit Built-in Safety Circuit Rechargeable 3500mAh Lithium Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker **Brand:** rapthor **Price:** € 137.40 **Availability:** ✅ In Stock ## Summary > 🔋 Power up your Onyx Studio with confidence and style! ## 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?** € 137.40 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.gr](https://www.desertcart.gr/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 - • **Install Like a Pro:** Includes screwdriver and plastic tool for a hassle-free, under-10-minute replacement experience. - • **Safety First, Always:** Advanced protection circuit guards against overcharge, over-discharge, and short circuits for peace of mind. - • **Power Through Your Day:** 3500mAh capacity delivers longer playtime than the original battery—never miss a beat. - • **Seamless Compatibility:** Perfectly fits Harman Kardon Onyx Studio 1/2/3/4 models—upgrade your sound without compromise. - • **Engineered for Durability:** Foam cushioning and extended, reinforced wiring ensure a secure, damage-resistant connection. ## Overview The Rapthor 3500mAh rechargeable replacement battery is designed specifically for Harman Kardon Onyx Studio 1 through 4 wireless Bluetooth speakers. It offers a higher capacity than the original battery for extended playback, comes with all necessary tools for quick installation, and features built-in safety circuits to protect your device. Enhanced wiring and cushioning materials improve durability and connection reliability, making it a smart, safe upgrade for your premium speaker. ## 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 ## Features - 3500mAh High Capacity: Higher capacity than original battery, longer-lasting performance. - Easy to Use: Simply quick install with included screwdriver and plastic tool. - Considerate Details: Foam strip for cushion absorbing, durable and longer than original’s 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. - Compatibility: Compatible with Harman Kardon Onyx Studio, Onyx Studio 2, Onyx Studio 3, Onyx Studio 4. ## Technical Specifications | Specification | Value | |---------------|-------| | Additional Features | Rechargeable | | Asin | B099NJVQQ7 | | Best Sellers Rank | #71,125 in Electronics (See Top 100 in Electronics) #1,567 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 | | Connectivity Technology | Bluetooth | | Connector Type | Proprietary | | Current | DC | | Customer Package Type | Standard Packaging | | Customer Reviews | 4.5 4.5 out of 5 stars (308) 4.5 out of 5 stars | | Enclosure Material | Lithium-ion | | 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 | | Specification Met | Li-ion Battery Standard, Higher Capacity, Easy to Install, Safe Performance | | Unit Count | 1.0 Count | | Upc | 735818080479 | | 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 on Reviewed in the United States 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 on Reviewed in the United States 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 on Reviewed in the United States 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 - for Harman Kardon Charger Onyx Studio 8 7 6 5 4 3 2 1 Wireless Bluetooth Speaker Replacement Harmon Kardon Charger 19V AC Power Cord Supply【10 FT】 VHBW - Charger for Harman Kardon Onyx Studio 8 7 6 5 4 3 2 1 Wireless Bluetooth Portable Speaker Compatible with Harman Kardon Charger 19V 38W AC Charger Fast Replacement Power Adapter --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.gr/products/406102328-rechargeable-3500mah-lithium-battery-compatible-with-harman-kardon-onyx-studio](https://www.desertcart.gr/products/406102328-rechargeable-3500mah-lithium-battery-compatible-with-harman-kardon-onyx-studio) --- *Product available on Desertcart Greece* *Store origin: GR* *Last updated: 2026-08-07*