Be Sure to Use the Right Charger
Besides the charging cable, the charger might also be the reason why your iPad isn’t charging correctly.
First, make sure that you’re using a good charger. It doesn’t have to be an Apple charger, but it does need to be a high-quality USB-certified charger that won’t put your iPad or yourself in danger.
Likewise, you need to make sure you’re using the right wattage. The charger you use should be at least 10–12W, but the higher the wattage, the better.
Using a 5W charger won’t work, as they don’t have enough power to charge a larger device like an iPad.