A charging connector is judged twice: once on the day it is installed, and again eighteen months later when a driver reports that the handle is getting warm. The first test is a datasheet. The second is mechanical endurance, and it is the one that decides whether a warranty claim lands on the supplier or on the operator.

The relevant question is not whether a connector works when new. It is what is left of it after ten thousand mate-and-unmate cycles — roughly one insertion a day for the better part of thirty years, or three years of hard use at a busy public post.

Mechanical endurance testing does not stop at counting cycles. After the cycling is complete, the electrical tests are repeated. A connector can still latch cleanly and still fail dielectric withstand, because the insulation has been abraded by ten thousand insertions. That second test is the one worth asking a supplier about.

Latch retention is the other half of the picture. A DC cable under load is heavy, and the latch is the only thing holding it in the vehicle inlet. Common specifications call for more than 500 N of pull force on the locking latch, so that a cable cannot be dragged out while current is flowing.

The environment matters as much as the mechanism. A connector that lives outdoors sees salt, UV and temperature swings between -40 °C and +85 °C. Neutral salt spray testing to ISO 9227, run for several hundred hours and checked for red rust on contacts and shell, is a more useful indicator than a single IP rating — because IP55 is measured on the assembled connector, and an unassembled housing tells you very little.

When comparing suppliers, ask three questions in this order: how many insertion cycles were run on the connector you are buying, was the dielectric test repeated afterwards, and can the batch code be traced to the test record. A supplier who can answer all three is usually the one who also answers when something goes wrong two years later.