While methodologies for carbon accounting in circular business models like storage reuse are still under development, they can offer valuable insights. Through comparative GHG impact analysis, these methods can highlight the environmental benefits of reusing storage devices versus manufacturing new ones. The concept of avoided emissions can be used to quantify the GHG reductions achieved through reuse. The use of a "functional unit" for comparison ensures a fair evaluation between new and reused storage devices. Two different approaches, attributional and consequential, can provide different perspectives on the impacts of storage reuse. However, these assessments may not fully account for indirect effects or future market and technology changes.