All the MobilePal battery cases for iPhones are capable of 1A input and 1A output at 5V. When charged with a compatible USB charger, you should be able to fully charge the battery case with your iPhone installed in about 6 to 6.5 hours, depending on the model. If it takes much longer to charge, the following troubleshooting steps may be useful:

  1. A likely reason for slow charging is an incompatible USB charger. Some USB chargers, especially those made specifically for Android smartphones, are not compatible with Apple products for fast charging. We recommend you to charge with a USB charger made for Apple products (such as the charger that came with your iPhone or iPad), or charge using a smart charger, like this one. 
  2. If you are using an Apple USB charger, and it still charges slowly, please check to make sure the micro-USB cable is not broken and is securely connected during charging. It is important to use a high-quality micro-USB cable for fast charging. If you have multiple micro-USB cables, you might try a different cable.

If both of these troubleshooting steps fail, you might have a defective product.  Please provide us with your order information so that we can further assist you with a refund, exchange, or warranty service.