2X Pack Z55H 3.85V 70mAh Battery Replacement for Sony WF1000XM4 WF-1000XM4 Industry Leading Noise Canceling Truly Wireless Earbud Headphones Battery+ Tools

Full transparency, I'm only 2 weeks or so into the swapping out of the batteries and I haven't had a chance to use the earbuds heavily since then. I'll update accordingly if things change.Pros:- Price is inexpensive- The kit they send to help with the replacement is a great touch. I saved the kit after I was done and plan on using it for other things in the future. Nice bonus.- About 2-3 weeks in, the batteries seem to be working very well and have restored the right earbud to as it was from the factory. Time will tell how long they hold up, but I'm optimistic.Cons:- None regarding the batteries and kit that were part of this purchase.What to watch out for:- Don't apply too much heat to the earbud you want to disassemble. Turning the earbud in your fingers while applying heat from a heat gun or hair dryer should do the trick. Apply even heat for 10-15 seconds and see if you can pop the housing apart.- I used a paper towel for cushion, applied pressure via a pair of pliers with the paper towel under the teeth of the pliers, and the case started to separate perfectly. Please use very little force when attempting to separate the halves this way as too much pressure could damage the earbud or mar the plastic surface.- When working on the replacement, be careful not to damage any of the ribbon cables inside the earbud.- To separate the circuit board from the top of the battery, I applied heat very briefly, followed by a back-and-forth motion with the included guitar pick looking tool until the circuit board was free from the top of the battery.- Removing the battery can be a bit difficult as it has a type of glue that helps keep it secure. Try to work around the edges of the OEM battery to fee it from this glue. You could also apply heat in short intervals until it loosens as well.- Make sure you drop the new battery into the earbud with the correct polarity facing upwards.- Reassemble in the reverse and you should be good to go. Charge the earbud(s) and test things out.I was a victim of the bad batch of batteries that Sony put into their earlier production of the WF-1000XM4 earbuds. After about 2 years of occasional use, and a firmware update in mid to late 2024, my right earbud would never charge past 95% and when in use, the right earbud battery would maybe last 30 minutes. I was less than pleased after having spent a considerable amount on these earbuds about 2 years or so ago from the time this started happening. I lived with it, opting to use my over the ear headphones for my long flights and didn't think much of it, other than vowing to never give Sony another chance on earbuds, I love their over the ear noise cancelling headphones though.In searching for this issue, I found this battery kit and decided to give it a try. What's the worst that could happen, the right side works 0 minutes versus 30 minutes? I used a YouTube video for the disassembly, removal of OEM battery, installing the new battery, and reassembly. I used a Milwaukee heat gun, and the glue softened quickly but a hairdryer would work as well. Took about 5-10 minutes per earbud, I replaced both so they would both have new batteries, and so far, all is working very well.

I didn’t need more than the sharp blade to slide in the gap and a squeeze to open the case. I was expecting to need force that would likely damage the outer case of each ear pod, but no! Nothing.I managed to ease the first cable off quite easily by the second that was attached to the top of the battery…..nope! So I just used the same sharp blade to free the glue from the underside of that connector and then just pried the battery out. It worked with no issues at all. Popped the new battery in and pushed the connector back onto the old adhesive. The top connector snapped into place just as the reviews stated. I placed the top case back on and tested the unit. To start nothing functioned and ai assumed I had somehow short circuited the thing. I popped it into the charger and that obviously reset it! It worked. After that I used some of the glue to attach it again and used the rubber to hold it together to strengthen.New headphones! Battery is great!

It works, but use a heatgun or hair dryer to loosen the case glue before prying it open.

The batteries seem to work. Definitely recommend looking up a youtube video on how to replace the batteries before doing it. The tools included werent the best. I ended up using sturdier metal tweezers to get this install finished. After the install, the batteries charged up well and seem to be holding up.

Needed to replace my batteries for my Sony headphones after their update tanked the battery. Now I’m back to roughly 6-8 hours battery

The battery works, but you can get the battery for cheaper elsewhere. The “kit” part is just a couple of very cheap plastic tools and a solidified glue.

Like many, my WF1000XM4 earbuds just died after about 2 years. A known issue that Sony is reluctant to acknowledge.Using the batteries from this kit took them from completely dead and refusing to charge to completely fixed. And they've been working perfectly for over a month now.If you have any electronics repair experience at all, it's not a hard job. I was able to open each earbud using a trigger grip and gently applying more pressure until each one popped open. No heat required. After that, I just followed one of the many video guides available online and had them fixed in half an hour.Before gluing them back together, I did fully charge and test the battery life on them and got over 8 hours easily. After that, I sealed them up with the included adhesive and everything has been great.Highly recommend this kit.

works, but a pain to remove the original battery