Systems and methods to detect particular levels of remaining battery capacities. A ratio of changes in battery output voltage over changes in battery capacity (ΔV/ΔC) is calculated. Detected rises in the value of this ratio are used to detect that a battery has a remaining capacity level that is near depletion. In a certain temperature range, the ΔV/ΔC ratio is used to provide an indication that the battery is approaching a low remaining capacity state. In another temperature range, an increase in the ΔV/ΔC ratio indicates that the battery has reached a mid-range remaining capacity level.