EXMUMCMR 𝟮𝟬𝟮𝟲 𝗡𝗲𝘄 𝗨𝗽𝗴𝗿𝗮𝗱𝗲𝘀 𝐙𝟓𝟓𝐇 𝐁𝐚𝐭𝐭𝐞𝐫𝐲,Compatible with Sony Headset Battery for WF-1000XM4(𝟐𝐏𝐂𝐒)+with Installation Tools Kit Z55H

Breathed new life into my long dead XM4 earbuds. Cells appear to be genuine Zenni Power cells. Despite careful work, I did break a small cable (90° cable not sandwich cable) and there doesn't appear to be any impact on use and functions. Sure it does something but touch, anc/passthrough, so on all works fine so who knows. I am ecstatic to have be beloved buds back.

These arrived quick. Easy enough to install and after charging my earbuds (wf-1000xm4) they appear to be holding charge well again. I replaced both left and right earbud batteries as I had time, and wanted to test longevity with the new replacements. Before, the right earbud would lose charge, go from 100% to 0% in an hour or less. It would also heat up in the charging case, and overall caused the case to drain quicker as well. Opening the earbuds was easy with a heat gun and spudgers. Replacing the battery took little finesse but still easily done. I did a quick test to the earbuds with a small charge before glueing. Just to be sure no other components were damaged. I let the glue cute for a full 24 hours while the earbuds were in foamed clamps to prevent damage/scratches. So far after about an hour and a half of use these new batteries went from 100% charged to 93%. Great improvement from before. I will continue this review as time passes. 9 months in and still going strong. Keep that tube of glue. I will have to re apply. The seams on my wf-1000xm4 are starting to be able to pull apart. (my fault there. i was cleaning the seam and didn't realize i was scraping glue out)

These batteries are labeled ZeniPower Z55H and they work well with my sets of WF-1000XM4 earbuds. Besides the heat gun, this package included everything needed to swap out the batteries. These new batteries with a full charge lasted 5 hours 10 minutes with noise-cancelling, much improved. For such a premium set of earbuds WF-1000XM4 from Sony, I expected the battery to last more than two years. But it has only been 1 year and 3 months, and one of the earbud became useless because of only 10 minutes of play time. Then 4 months later, the other could last only 20 minutes. I was going to throws my earbuds away, but hanks to those tutorial videos online, I can give this set of premium earbuds a second life. It turns out that this battery problem was not an isolated incident. Shame on Sony.

The tools included are mostly not needed, and the the ones that are, such as the tweezers are absolute garbage. The ribbon cable that needs to be pulled out requires more gripping force than they can give. The adhesive was bad and couldn't be squeezed out.

After owning them for 2 years, the batteries in my earbuds began to fail, with them only lasting 1 to 2 hours after fully charging. So I bought this set of batteries and used a guide on iFixIt to install them. Now both earbuds are back to lasting a whole 8 hours, saving me from having to buy a whole new set of Sony's expensive earbuds! Also of note, these batteries are branded ZeniPower, just like the ones Sony installed during manufacturing. I do not know for certain that they are genuine ZeniPower batteries, but they are very close. The originals (Left side and closer in the photos) had a slightly more prominent blue ring around them, but other than that, no visible difference.

To be honest, this pack comes with a lot of tools, but all you really need are the tweezers, picks, a plastic lever, the finger glove, and glue—of course, the batteries too. Besides these, a heat gun and a clamp are necessary. It's not difficult work; all you need is patience and careful attention. If you already have the right tools, I’d recommend just buying the batteries, which is why I gave it 4 stars. Now, I need to check how long the new battery lasts after a full charge.

When successfully installed, they revitalized my old earbuds to their brand new battery life. However, it's tricky to do, and I killed one of my earbuds through lack of care. But the batteries and tools are great

Used a heat gun I purchased on amazon to melt the adhesive and open the earbuds. A few delicate maneuvers later (watch a youtube video) and I had the old batteries out and new ones in. Added a few dabs of the adhesive and left them to set overnight with some clamps gentle holding the two halves in place. Been working flawlessly since. Rarely see the battery drop below 90% when it would run "100%" to dead in less than an hour before the change out.