DC 3.7V 650mAh AHB622540N01 Rechargeable Lithium Battery for Sennheiser Momentum 2.0 HD 4.40 HD 4.50 450BT Urbanite XL Wireless Bluetooth Headphones Aerox 9 Aerox 5 Mouse

Installed the day it arrived, this upgraded a common consumer item with an internal rechargeable battery that was worn out and not functioning. Today, this little battery is going strong and I have a resurrected item and one that will maintain a charge for a very long time. :-) Great purchase. By the way, if you've never swapped out the cheaper rechargeable batteries that come with most consumer electronics, they are inexpensive to buy and so very easy to install. They all have the same plug! You just need to make sure the battery size and specifications will work for your device. Search the video social media for instructions! You can do this too!

Fixed my 11 year old headphones that I’m soul bonded to with this amazing work great battery that lasts for days and great value for the money

After 5 years my Avantree HT4189 wireless headphones needed a new battery. Ordered this and it fit and worked perfectly. It's a little tricky to solder in but now my 40 hour headphones have 50% more battery capacity. The original battery was only 550 mAh.

Exact swap with OEM.

Battery fit my momentum 4s with a little bit of adjustment. Price wise pretty fair. As easily as install as anything else if you know what you’re doing. The battery life is not as good as the original but still pretty darn good, and the plug matched up no problems,

The original battery on my Momentum 3 earphones stopped holding a charge. This was a perfect replacement fit, and fairly easy to replace. It’s a higher capacity than the original battery so now can power the headphones for more than a day, where the original one barely made it a full day (with active noise canceling)

I've had the Momentum 3 wireless headphones from Sennheiser for a few years and absolutely love them, but the battery life had never been its strong point and over time it had dwindled down to a measly 6 hours or so. After putting this battery in (which is 800 mAh as opposed to the original 700 mAh), I can get 18+ hours of continuous use while also in noise cancelling mode. Super easy to replace, and the polarity on mine matched the original connector.Also, if you're worried about replacing the battery in your quality German made headphones with a cheap, Chinese knockoff then don't be. I was surprised to find that the original battery that I took out was made in China as well, so this isn't even a quality downgrade from the original.

So, i bought the Momentum 3 battery for my Momentum 2 headphones. First off, it is shorter so i put a small piece of foam by it in the tray to hold it in place, secondly it is thicker, doesn't matter. The plug is the same and this battery has 30% greater capacity so I decided to go for it. I bought a correct one a while back but it never worked for charging so I tried again with this one. It indeed charges. Anyway, baring a rapid failure to hold a charge I consider this battery great. It has revived my 10+ year old headphones to working more than a couple hous a charge... I hope I get something comparable to when they were new or better.