Slow to charge

Your description suggests that your iPad battery may be failing - and need service. You would be best advised to take your iPad and Power Adapter along to the Genius Bar at your local Apple Store - where the technicians can test and identify the problem.

Alternatively, you might directly contact Apple Support - and request a remote battery diagnostic. You’ll find the Contact Support link at top-right of this page.

Here are Apple’s support pages that cover battery and charging issues:

Charge and monitor the iPad battery - Apple Support

If your iPhone or iPod touch won't charge - Apple Support

If your iPad won't charge – Apple Support