One of the cheapest ways to widen a charger range is to build several SKUs on one certified platform. But the saving only appears if the variations sit in the right layer of the product.
What varies freely
Colour, finish and logo application. These touch nothing that was tested and require no new reports. Cable length and colour, pouch, manual and carton artwork are equally free — they are procurement decisions rather than engineering ones.
What varies cheaply
The plug system, if the platform was designed for it. A body that accepts interchangeable heads gives EU, UK, US and AUS variants from one product. Port labelling and the printed specification table are also free, provided the underlying port layout does not change.
What varies at a cost
The power stage. A different wattage means different components, a different transformer and usually a partial re-test. It is still cheaper than a new platform — the enclosure, plug mechanism and packaging can often be shared — but it is engineering work, not a configuration.
What cannot vary
The mechanical enclosure tooling and the safety-critical clearances. Changing the housing means new tooling and a re-tested configuration. This is the line that turns a cheap variant into a project.
How to plan a range
Decide the range before the first tool is cut: which wattages, which port layouts, which plug systems. Then design the enclosure once, with enough room for the largest board in the range, and let the smaller SKUs use the same tooling. A range planned this way shares tooling, packaging dies and certification groundwork; a range planned one model at a time pays for everything three times.
The commercial argument
A distributor buying three SKUs from one platform gets one specification, one test report family and one packaging system — which is easier to sell internally than three unrelated products. That is worth more than a marginally lower unit price.