What makes a battery-health estimate more or less trustworthy?

The report should state what it measures or estimates. Remaining usable energy, a BMS health value and a range-based inference are different quantities. An unexplained percentage is weaker evidence than a clearly defined measurement with a reference.

Check that original and current capacities refer to the same usable or gross boundary and exact variant. A high-quality current measurement cannot fix an incorrect original baseline. Document both sources rather than treating the denominator as a harmless default.

Look for the test conditions, date, equipment or method and known limitations. This does not require sharing private diagnostic files publicly. It requires enough explanation to understand what conclusion the procedure can reasonably support.

Two screens copying the same underlying BMS value are not two independent measurements. Agreement between compatible independent methods can be informative, while disagreement deserves investigation. Avoid counting repeated displays of the same source as extra certainty.

A useful assessment explains uncertainty and unresolved issues. It does not convert incomplete evidence into an exact failure date or a categorical buying instruction. The practical outcome is a clearer next question, an appropriate follow-up or a better bounded estimate.