3500mAh Rechargeable Replacement Battery Compatible with Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker

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

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.

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.

This was for a HK Onyx Studio 4 speaker only. Battery is slightly smaller than original but the adhesive foam cushioning takes up the difference in size, I also used pieces from the original battery to use as cushioning where wires get passed thru the battery housing. Supplied screwdriver and plastic tool were not any help for the Onyx 4, as screws are regular philips screws and there is no notch to use the plastic tool to pry the speaker cover off. I used a knife edge to get the prying started then used Nylon auto trim tool set to complete the removal. Gave a Four Star rating because two tools given do not help. Battery worked immediately when all hooked up but I am not sure how long it will last after charging.

Very good quality , l love this battery

Good price for battery. Included tools and instructions for removing old battery and installing new battery. New battery has a higher capacity and fits perfectly in my Harmon Kardon Onyx 4 speaker.

I only type reviews on something that really sucked or something that went above and beyond. this is how all products should be. specialty tools and step by step readable instructions included and a battery that fit and worked like it should. Harman/Kardan informed me battery was not replaceable and wanted me to buy a new speaker. price of 479.00. but did offer me 20% off new one.. the original batteries don't last long and can cause issues when dying.

Installation was easy but the quality and life of the replacement battery was poor. At most, the battery lasted about three months - I would've ask for a refund if not for the short return windows for Amazon.