• EEVblog 1732 - 20yo 1000+ Cycle Panasonic Li-Ion Battery TESTED EEVblog3 weeks agoBatteries,EEVblogComments Offon EEVblog 1732 - 20yo 1000+ Cycle Panasonic Li-Ion Battery TESTED2,194 Views Facebook Twitter LinkedIn How much capacity has this 20+yo 1000+ cycle Panasonic 14500 lithium ion battery lost? • 00:00 - Panasonic electronic shaver teardown06:30 - Battery dimensions match the type number08:24 - The battery capacity test setup10:40 - 500mA Constant Current test11:38 - How much energy is left in a “flat” battery?13:46 - 250mA Constant Current test14:54 - 100mA Constant Current test15:13 - Results analysis. • Talking head Dave19:11 - How to scale time in Excel21:20 - How to get a characteristic battery capacity graph in Excel24:35 - Energy in a battery and the characteristic curve area, it’s just an integral26:30 - Optimising product design and battery cutoff voltage29:13 - Battery current measured Forum:https://www.eevblog.com/forum/blog/eevblog-1732-20yo-1000-cycle-panasonic-li-ion-battery-tested/ Podcast:Download

Article Summaries:

  • In episode 1732, EEVblog host Dave Rogers evaluates a 20‑year‑old Panasonic 14500 lithium‑ion cell that has undergone over 1,000 charge‑discharge cycles. He first teases the shaver teardown, then confirms the battery’s dimensions match the type number. Using a constant‑current test rig, he measures capacity at 500 mA, 250 mA, and 100 mA, noting the energy remaining in a “flat” cell. Results are plotted and analyzed, with Dave explaining how to scale time and generate a characteristic capacity curve in Excel. He concludes by discussing how the data informs product design and cutoff‑voltage decisions.

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