Just to clear a confusion before the replacement. Please send us the picture of the last indicator, which you mean is always blinking. 

Actually, the first oval-shaped indicator on the right is not a battery indicator. It indicates that the battery is ready to charge your devices wirelessly. The other 4 LEDs indicate a charge, and after recharging it fully, all 4 LEDs will turn off except the first wireless charging indicator. The oval-shaped wireless indicator will keep blinking on full charge until and unless you connect your phone to it for charging wirelessly. It is a normal phenomenon for these powercores.

When the powerbank is connected to the power source, it will turn off all of its 4 battery indicators after fully recharging itself. The first wireless indicator will keep blinking, which means it is ready to charge your iPhone in pass-thorough mode.

If you have any questions, please feel free to contact us.