Kratax 3500mAh Rechargeable Replacement Battery for Harman Kardon Onyx Studio 1/2/3/4 Wireless Bluetooth Speaker, Real Capacity, Same Quality as Original Battery

The tools and the battery are working great. The battery lasts for 4 hours now. I am glad I can take my Onyx 1 whenever I go. The only thing is the battery cord isn't really wrapped by that protector as shown in the photo. Also, the battery capacity is 3200 mAh. It's not a biggie, but I just feel photo and its battery capacity needs to be true to the product.

Great product and price, exactly as described and easy to install

Kit is ok, I've used 3 of them now in a Onyx 2 and two 4's. Battery is smaller than the OEM cell but regular 18650's can in theory have the advertised 3500 capacity. I haven't been using them long enough to verify, but they are basically drop-in, charging works as normal, and the speakers work as normal again. The problem is if you leave them plugged-in all the time, the Onyx is just going to kill the battery again over time because there's no good shut-off behavior for charging while plugged-in. This is what is killing the battery, and it'll just happen again. What I've done is wired a simple switch into the positive battery lead and mounted it in the bottom of the carry handle recess. Charge the battery up, flip this switch off, and now you can leave the speaker plugged-in all the time without killing the battery. If I'm going to use it on battery power, switch the battery back on, top it off if need be, and unplug and go. Self-discharge of the battery is slow with it unconnected like this. I'm not sure if this is really worth the effort because the battery life is short no matter what, but I didn't see the point of even bothering with replacing the battery knowing it would just get killed again. The 2/3/4 are really great speakers and short of this battery issue mine have all held up for many years with nothing really beating them for the size/performance. If you regularly run yours off the battery then it is definitely worth the effort.

Not happy how it came with no packaging, inner box open all parts not secured, no instructions. I did go online , now I know how to take speaker apart and install new battery. Product works very well.

Well made, foam isolated to keep rattles out. Fit perfectly as described. Just like it always was. Easy to install, good accessory tools. Battery life is something you don't appreciate til it's gone.

Okay, for some reason when I purchased my speaker. I did not realize it was supposed to be wireless. By that time. The warranty was out. I opened it up. I replaced it with this battery system. It wasn't too difficult and it works just great. It's nice to have that feature. I have the battery at least 5 years

20 minute job saved my Onyx 4! Watch a video on youtube for procedure and so you dont' bust little plastic bits, but yes...this is the real deal.

The toolset for replacing the battery was completely up to the task, as I've managed to disassemble my Onyx 4 device and replace the battery as explained in the YouTube video. Speaking of the battery, it charged fine and the device was capable playing on the battery power for hours. The only drawback came from the mechanical aspect - unlike the original battery pulled from the device which snuggly fits the battery compartment, the purchased replacement was a bit shorter and a bit slimmer. The non-snug fitting was one of causes of auddible rattling when audio signal was loud in the low range. Fortunately, it was easy to overcome by wrapping the battery in a piece of paper towel. Just for the record - another smaller magnitude cause of rattling was incomplete tightening of screws connecting the two halves of the loudspeaker. To be completely fair - it could be that the replacement battery has been designed to fit multiple devices. All in all, I am happy to have been able to prolong the life of excellent product. The mechanical adjustment didn't turn out to be a bid deal.