Before you plunk down $129 for Apple's new "Pencil" stylus, you should be aware that the device will not charge via the standard "Qi" wireless power technology, according to Apple.

In response to an inquiry from ZDNet, an Apple spokesperson confirmed that Apple Pencil doesn't support Qi. The only way to charge the device is by resting it on the side of the iPad Pro computer. Apple did not provide comment as to why Qi is not supported in the device.

Also: How to use Apple Pencil: 21 features, tips, and tricks

Both Apple Pencil, the second version of the stylus, and the new iPad Pro were introduced last week by Apple at a media event in New York City. The new Pencil works only with the new iPad, not with previous versions of the iPad. (The first-gen Pencil is still available and works with older iPads, and costs $99.)

Also: Here's the iPad Pro that professionals really want

The wireless charging of the second-generation Pencil replaces the "Lightning" connector nib in the prior Pencil, located at the base of the stylus, under a removable cap. Charging the old model required the cap to be removed and the nib to be inserted into the Lightning port of the iPad.

Qi wireless charging pads are available from numerous vendors and are able to charge all Apple iPhones since last year's iPhone X and iPhone 8. The charging technology, developed by an industry group known as the Wireless Power Consortium, consists of a coiled wire in the charging pad that generates a magnetic field that in turn induces an alternating current in a corresponding coil in the receiving device.

Also: New iPad Pro rivals 2018 MacBook Pro's performance, say benchmarks

The new iPad Pro uses a system of wireless power to charge the new Pencil when it is placed on the special area on the side of the iPad, but apparently that charging system is different from Qi. TechCrunch had a nice discussion of the system.

The Apple Pencil has received favorable early reviews from those who've had a chance to tinker with it, especially for the ease with which the magnetic grip of the iPad allows the Pencil to effortlessly attach and stay attached and charge.

Apple last year said it would offer its own Qi-compatible charging pad for the iPhone, the AirPods headphones, and the Apple Watch. That device has been delayed and is now expected some time in 2019.