user46482: Hello so i build a nodemcu wifi controlled car, everything works fine expect i have one small issue, currently i have 2 9v batterys, one of them is connected to motor controller and other one is connected to nodemcu.. but the nodemcu's 9v battery gets hot in a minute and stops working. What am i doing wrong? + is connected to vcc and - is connected to grnd on nodemcu.


user4143: 
the nodemcu's 9v battery gets hot in a minute and stops working. What am i doing wrong?

You're using a 9V battery.
Those batteries are useless. They have very little capacity, and can provide very little current. The NodeMCU needs a lot of current. 
Choose a better battery. Maybe a Li-Poly battery would be good (mobile phone batteries are good for this).

46482: <p>Hello so i build a nodemcu wifi controlled car, everything works fine expect i have one small issue, currently i have 2 9v batterys, one of them is connected to motor controller and other one is connected to nodemcu.. but the nodemcu's 9v battery gets hot in a minute and stops working. What am i doing wrong? + is connected to vcc and - is connected to grnd on nodemcu.</p>

<p><a href="https://i.stack.imgur.com/feU6u.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/feU6u.jpg" alt="enter image description here"></a></p>
 4143: <blockquote>
  <p>the nodemcu's 9v battery gets hot in a minute and stops working. What am i doing wrong?</p>
</blockquote>

<p>You're using a 9V battery.</p>

<p>Those batteries are useless. They have very little capacity, and can provide very little current. The NodeMCU needs a <em>lot</em> of current. </p>

<p>Choose a better battery. Maybe a Li-Poly battery would be good (mobile phone batteries are good for this).</p>
