Sometimes, important lessons crop up in unexpected places. The new iPads come with 12 Watt adapter bricks, rather than the 10W ones that came with previous generations, so we wanted to make sure our existing 30-pin cables would work with them. After all, it’s easier to use one brick and just switch the cables if you had more than one device, such as when traveling. That it’s a slightly higher-output source also suggested slightly-faster charge times. As it turns out, that wasn’t always the case.

In our test, we tried three different cables: a 36” Apple-branded cable, a 72” Newer Technology cable, and a generic 36” cable.

The test was simple – start with a discharged 3rd Gen iPad, connect the 12W power supply via each cable and see how long it takes to charge with the backlight on. Here’s how the times broke down.

• Apple cable: 6 hours and 3 minutes.
• NewerTech cable: 6 hours and 4 minutes
• “Generic” Cable: 22 hours and 59 minutes.

As you can see, there was something considerably different about the “generic” cable; with the backlight on, it barely trickle-charged. The main thing we noticed was that it was a narrower gauge than the Apple and NewerTech cables, and not as high-quality.

The lesson here is that you should make sure you are using good quality cables with your iPad 3 or 4 if you want to take the shortest amount of time to charge.