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Battery cell swelling after months usage is a widespread issue in notebook. Various cell‐swell studies point to

cell’s high SoC (state of charge) and temperature as two major contributed factors. At high SoC and

temperature, battery cell swells more and degrade at much faster speed, while significantly slower rate at

low SoC level and temperature.

Common mitigation involves mandatory SoC step down after certain period elapse. For example, capping

battery SOC at 80% (not 100%) after 9 months notebook usage. Some smarter policies try to learn and

classify its users into different categories: AC user, mobile user, etc. Then apply different step‐down timing

accordingly, Such as 1 month for AC user while 15 months for mobile user.

The disclosure proposes a method to quantify swell process by introduce “swelling credit” concept. If credit

runs out, swelling is about to occur. As it anchored by actual cell‐level tests, the model is reliable. Moreover,

by tracking “swelling credit” left in real‐time after battery in service, cell swelling process is measured in

runtime, thus enables system intervention at optimal time. System intervention includes either SOC

stepdown or cell temperature moderation or both, that is to affect cell’s operation temperature on rate of

cell charging and discharging.

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