The gap between a power bank’s shared total and one USB-C port

Method

One subtraction; no guessed port sums

For each reviewed US model with an explicit combined-output rating, we calculate combined total − strongest single-port rating. Each input identifies its exact OEM source and check date. Only published combined totals enter the comparison; separate port maxima remain separate when no total is stated. The signed difference is arithmetic context, not additional wattage available through the strongest port while it is at maximum.

We analyse manufacturer-claimed ratings as published; the arithmetic difference is our derived comparison, not a separate port rating. A negative difference remains visible instead of being silently discarded.