Editing Fitbit Sense and Versa 3 Battery Performance Program (section)

==Aftermath of software update==
According to Google, Users with "Impacted Devices" can expect to encounter decreased battery capacity.<ref>{{Cite web |last=Diaz |first=Nickolas |date=23 Jan 2025 |title=Fitbit has a battery overheating problem and here's what to do if you have one |url=https://www.yahoo.com/tech/fitbit-battery-overheating-problem-heres-200118269.html?guccounter=1 |url-status=live |access-date=22 Mar 2025 |website=[[yahoo!]]}}</ref>

Google has also received a 12.5 million dollar penalty for  failure to immediately report serious burn hazards with their Ionic Smartwatches<ref>{{Cite web |date=23 Jan 2025 |title=Fitbit Agrees to Pay $12.25 Million Civil Penalty for Failure to Immediately Report Serious Burn Hazard with Ionic Smartwatches |url=https://www.cpsc.gov/Newsroom/News-Releases/2025/Fitbit-Agrees-to-Pay-12-25-Million-Civil-Penalty-for-Failure-to-Immediately-Report-Serious-Burn-Hazard-with-Ionic-Smartwatches |url-status=live |access-date=22 Mar 2025 |website=[[CPSC]]}}</ref>

===Aging lithium-ion batteries===
Lithium-ion batteries face degradation as they age:
*Loss of active lithium ions through repeated charge cycles
*Growth of the Solid Electrolyte Interphase (SEI) layer
*Physical expansion & contraction stress during charging cycles
*Potential for dendrite formation in aged cells
*Increased internal resistance over time<ref>{{Cite web |last=Chu |first=Tien-Fu |last2=Rajendran |first2=Raja |last3=Kuznetsova |first3=Iren |last4=Wang |first4=Gou-Jen |date=31 Mar 2020 |title=High-power, non-enzymatic glucose biofuel cell based on a nano/micro hybrid-structured Au anode |url=https://www.sciencedirect.com/science/article/abs/pii/S0378775320301476 |url-status=live |access-date=22 Mar 2025 |website=ScienceDirect}}</ref>

*The company states that a limited-number of units are affected. This would suggest a manufacturing batch issue<ref>{{Cite web |last=Warwick |first=Stephen |date=22 Jan 2025 |title=Fitbit issues battery overheating warning over two of its most popular watches – and it might compensate you if you're affected {{!}} |url=https://www.techradar.com/health-fitness/smartwatches/fitbit-issues-battery-overheating-warning-over-two-of-its-most-popular-watches-and-it-might-compensate-you-if-youre-affected |url-status=live |access-date=22 Mar 2025 |website=techradar}}</ref>

===Potential manufacturing variables===
Several factors could explain why only certain devices are affected:
*Different battery suppliers or manufacturing batches
*Variations in battery cell chemistry or construction
*Manufacturing date ranges coinciding with specific material supplies
*Quality control variations between production runs

These technical considerations suggest the update may be a preventative measure against potential battery safety issues, rather than planned obsolescence. However, Google's limited transparency about the specific technical justification has left users unable to verify this interpretation.<ref>{{Cite web |last=Purdy |first=Kevin |date=7 Jan 2025 |title=Google Pixel 4a gets an unexpected update: Lower battery life |url=https://arstechnica.com/gadgets/2025/01/good-news-bad-news-pixel-4a-is-getting-an-update-but-it-reduces-battery-life/ |url-status=live |access-date=22 Mar 2025 |website=ArsTechnica}}</ref>