Can I use a power bank connected with Arduino joined with two DC motor?

Let's split this into two cases:

1) The answer is NO

2)The answer is YES

                                              The answer is NO

                        Yes, we can't power an Arduino joined with two DC motor connected to the  power bank. It all depends upon the motor configurations, the power bank output power and the connected style. Connecting a 6V/12V DC motor to the Arduino power pins of 5V and GND is not recommended. Though Arduino power pins are designed to power the LED and the sensor modules. It is not designed to power high current DC motors. Connecting the DC motor to the Arduino power pins will cause the Arduino board to malfunction and it makes the IC not properly executing the program code. And also sometimes it will fail. Motors can take different current, different voltages at different loads. This thing is also applicable for low rated DC motors. So it is highly recommended not to connect DC motor to the Arduino power pins which in turn connected to the power bank.

                        The answer is YES

    

                        NO, we can power an Arduino joined with two DC motor connected to the power bank, if the DC motors are connected to the power bank power supply instead of connecting it to the Arduino power pins. If your motor is rated at 6V/3V  or below then you can connect the motors to the motor drive shield ICs which are available at online at low price which in turn connected to the  power bank power supply.  If your motor is rated at 12V or above you can use a motor drive shield which is powered by a different power source(the power source should not be less than 9V) and it signal or digital pins are connected to the Arduino. In this way it is good for the Arduino because the DC motors takes power from the motor drive shield which is connected to an power supply rated as same  as the motor rating. Motor driver shield are available at low cost online if you want to buy it:

                        We should be very careful while powering electronics particularly Arduino is a sensitive board even a not enough power can able to make Arduino board malfunctioning.

                        Hope you guys learned something new and keep learning !!!!!

                         Eat, Sleep, learn and Do guys !!!!!!!!