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 can attest that these are good enough for replacing a dying battery in your earbuds, they're a matched fit replacement. I use mine daily at work and after a year and a half of regular use they are no longer charging fully or lasting even 6 hours. But that's from charged to nearly dead... 5 days a week, for a year and a half. So they absolutly work, even if not as good as the original battery life. The tools are meh, get yourself a good razor blade or exacto knife, a thin strip of plastic (like from packaging) and patience, sliding it around the seam to break the adhesive on the buds and pop them apart, using the tweezers to lift and disconnect the ribbon cable from the two halves and be careful and patent pulling the old batteries out. The included adhesive is a joke. I've replaced both my own and my girlfriends earbuds and BOTH had the earbuds falling apart again with short term use. Pickup some super glue and apply just a TINY bit in a couple spots along the seam, spread it with a piece of plastic then push the halves together and use a piece of tape to HOLD them together for a few minutes while the glue cures. (Just make sure you connected that ribbon cable and checked to make sure the earbuds Work properly before you glue them together, and if you can, use a tiny bit of isopropyl and a tissue to clean the seam as earwax and grease will prevent the glue from bonding. Just don't spill or wipe the electronics inside with it or it will short out and kill the earbud! (best to clean it when old battery is removed before installing new battery) Overall, they're a good and cost effective way to prolong the life of your slightly dated but still very good quality earbuds to be able to keep using them longer, instead of needing to fork out a large sum of money for a replacement pair. I give them a 5 out of 5 even though they're fading a year and a half later because the original batteries only lasted 2 ish years before they started fading too with how regularly and often I use my earbuds. Just take your time doing this replacement, in a well lit area and if you got it, use a magnifying glass!

I got real zenipower batteries (US shipment, mid Dec 2025). They look exactly like the oem ones I took out of the xm4 earbuds. They work well so far. You don't need the tools they send, but the batteries are good and the glue is nice.

Worked well. The rubber cement glue that was included was helpful for sealing the case together but also for holding the top contact to the negative side of the battery. Glad I got life back into these headphones.

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.

Effective and (relatively) easy to use replacement kit for the Sony WF-1000XM4. You may need to warm the earbuds up - and if you do, be cautious about the touch controls and the ear-tip connection. I've slightly deformed either on multiple sets, and while this does not affect the performance, it's something that could otherwise be avoided. I can't speak for this specific kit's longevity, but the first kit I purchased that was a mirror of this kit lasted ~1.5y before needing to be redone. Still - an inexpensive option vs purchasing a new set of earbuds.

like: Well, they work. And process is "doable." dislike: After a few months, usable time is down to maybe 20 minutes. That Is Not Good. value: No cost is too much to undergo this replacement process for bad batteries. in sum: Look elsewhere for replacement batteries for this earphones.

These batteries perform precisely as advertised for my Sony earbuds. I recommend watching the YouTube video for guidance. The most challenging aspect is opening the device; once open, caution is advised. Applying gentle pressure while lightly heating the casing is necessary to facilitate opening. I observed that the original batteries had significantly bulged. After approximately one month of use, I have experienced no issues, and the earbuds maintain their charge as if they were new.