Sony's WF-1000XM4 earbuds: Difference between revisions

Thousands of users, following firmware version 1.4.2 (released July 2022), have reported severe and uneven battery depletion, typically affecting one earbud. Most often the right. Symptoms include rapid discharge (for example, 1–45 minutes of playtime) and unusually high temperatures when charging.<ref name=":0">{{Cite web |title=WF-1000XM4 - Severe Battery Issues |url=https://www.reddit.com/r/SonyHeadphones/comments/x7mx2n/wf1000xm4_severe_battery_issues/ |access-date=3 Aug 2025 |website=[[Reddit]]}}</ref>

At least four documented cases involve earbuds physically swelling or splitting open with audible “pop” and chemical odor while charging in the case.<ref>{{Cite web |date=21 Feb 2023 |title=Sony WF-1000XM4 explodes while charging |url=https://thewalkmanblog.blogspot.com/2023/02/sony-wf-1000xm4-explodes-while-charging.html |access-date=3 Aug 2025 |website=thewalkmanblog.blogspot.com}}</ref> One user reported an earbud splitting while being removed from the ear during a meeting. Additional cases were documented via community forums in mid-2023.<ref>{{Cite web |date=12 Jul 2023 |title=Two More Sony WF-1000XM4 Battery Failures |url=https://thewalkmanblog.blogspot.com/2023/07/two-more-sony-wf-1000xm4-battery-failures.html |access-date=3 Aug 2025 |website=thewalkmanblog.blogspot.com}}</ref>

*Possible use of ZeniPower (Z55H) cells in early production batches (mid-2021 to mid-2022) being more susceptible to overheating.<ref>{{Cite web |date=Jun 2022 |title=WF-1000XM4 Sudden Battery Drain Issue {{!}} 2 days after warranty period ends! |url=https://community.sonylatvija.com/t5/portable-audio/wf-1000xm4-sudden-battery-drain-issue-2-days-after-warranty/td-p/3873533 |access-date=3 Aug 2025 |website=community.sonylatvija.com}}</ref>

Firmware v1.5 and v1.6.1 were released to mitigate the issue, but Sony stated only that these updates “reduce” battery loss rather than repair existing damage.<ref>{{Cite web |date=6 Dec 2022 |title=Sony WF-1000XM4: Latest firmware update may worsen battery life for some earbuds |url=https://www.notebookchat.com/index.php?topic=159996.0 |access-date=3 Aug 2025 |website=notebookchat.com}}</ref>

*Sony official community posts noting uneven battery drain and overheating.<ref>{{Cite web |last=@angrymango |date=11 Oct 2022 |title=Can Sony acknowledge the battery issue with WF-1000XM4 firmware vers. 1.4.2? |url=https://us.community.sony.com/s/question/0D54O00007iqVLYSA2/can-sony-acknowledge-the-battery-issue-with-wf1000xm4-firmware-vers-142?language=en_US |access-date=3 Aug 2025 |website=us.community.sony.com}}</ref>

*Independent blogs documenting battery swelling and explosions.<ref>{{Cite web |date=12 Mar 2023 |title=Another Sony WF-1000XM4 battery failure |url=https://thewalkmanblog.blogspot.com/2023/03/another-sony-wf-1000xm4-battery-failure.html |access-date=3 Aug 2025 |website=thewalkmanblog.blogspot.com}}</ref>

*Reviewer coverage advising warranty claims.<ref>{{Cite web |date=17 Mar 2023 |title=Sony WF 1000 XM4 – We Were Wrong! |url=https://www.dhrme.nl/sony-wf-1000-xm4-we-were-wrong/ |access-date=3 Aug 2025 |website=dhrme.nl}}</ref>