One of the major improvements of the Apple Watch 7 is that it charges 33% faster than its predecessor. This means that it can now charge from an empty battery to 80% full in just 45 minutes.

However, as Gizmodo discovered, this speedy charging requires the right charger: when the Apple Watch 7 is attached to an older-generation charger, the wearable charges at a similar speed to the slower older model.

For reference, the Apple Watch 6 can be fully charged in 1.5 hours.

This won't be a problem if you're careful; as Gizmodo noted, Apple has decided to include a fast charger in the box, and is also replacing the slow charger with a new fast charger on Apple's website if you want to buy a spare for the office.

Nevertheless, the cables look remarkably similar, so it is easy to pick the wrong one when you are in a hurry or mistakenly purchase a discontinued one from a different vendor. The key is to check the connector used. Previous generations used USB-A, while the newer ones use a smaller, oval-shaped USB-C connector.

Oddly enough, even a week before the Apple Watch 7 hits store shelves, you may already have one; MacRumors reported in September that the lower-priced Apple Watch SE ships with a USB-C fast charger. This is a clear sign that Apple means it when it says the old charger is discontinued. Even if they were technologically advanced, it must be more cost effective to make one charger.

Apple Watch 7 pre-orders opened yesterday, and early adopters will have the new wearable on their wrists on October 15. Prices start at $399 for the 41mm model and go up to $429 for the 45mm version. If cellular connectivity is required, there will be an additional charge, starting at $499 and $529, respectively.