If I have a USBC cord for my IPad, do I need a power adapter if I plug it into a USB outlet?
Does an adapter charge my iPad faster that plugging it directly into a USB wall plug?
iPad 2, iOS 9
Question marked as
The charging performance of your iPad will be principally determined by two factors - these being the model of iPad - and the Power Source (or Power Adapter) to which it is connected for charging.
The tags appended to your post suggest that you may have a very old iPad2. This and other very old model iPads will not benefit from, or charge any faster, when connected to any USB Power Adapter or USB outlet rated at 5V/12W or greater.
Very old models of iPad were supplied with either a 5W (i.e., 1.0A @5V) or 10W (2A @5V) Power Adapter; many in recent years where supplied with a slightly more powerful 12W (2.4A @5V) Power Adapter. All recent iPads are now supplied with a 20W USB-C Power Adapter.
In more detail, most models of iPad require a Power Adapter rated at 12W (i.e., 2.4A @5V) or greater to reliably charge. 5W Power Adapters (1.0A @5V) intended for older models of iPhone are inadequate to charge the vast majority of iPads; if the iPad charges at all, charging will be very slow.
Some third-party USB-C power adapters (and portable PowerBanks) may not support USB PD (Power Delivery). Power Delivery mutually negotiates the charging voltage; the source, load and cable are all elements involved in the negotiation protocol. Unless the Power Adapter explicitly supports USB PD, it will almost certainly fail to charge the iPad; proprietary charging standards, such as QC (Quick Charge), are not supported.
Many computer USB ports also cannot source sufficient power to charge an iPad. Unless explicitly designed for charging connected devices, computer USB ports are typically limited to 0.5-1A @5V (i.e., 2.5-5.0W).
I hope this insight provides some clarity at to benefits, if any, for your particular iPad.
