50$ robot- batteries heating up

[SciOlyStudent]

I have finished the circuit to the 50$ robot (finally) and am glad to say that when I plugged my batteries in, nothing sparked and no catastrophic explosions occurred, but I found that after having the batteries plugged in for no more than 20 seconds, the the batteries started heating up.  I checked the circuit and there was electricity running through the entire circuit, so it is not a matter of the leads coming from the batteries touching.  Is there a problem in the circuitry or is this a natural happening?  What really concerns me is the potential of leaving the batteries in too long and them blowing up...  Any help/explanations?

[ed1380]

what battery?

[cooldog]

probebly the batty used to run the servos and circut board

[SciOlyStudent]

Sorry, I have 4 AA batteries that are going to power my circuit board and my servos and they heat up very quickly once they are plugged in... Will this disappear when I have everything plugged in (servos, sensors)?  I just need to know why the batteries may be heating up so quickly and how I can stop it.

[cooldog]

I'm not sure but it could be because nothing is using the outlets (sensors , servos) try plugging them in then  try it, also do the battery's run dead more quickly then usual

[ed1380]

probebly the batty used to run the servos and circut board

you figure that all by yourself, or mommy told you? 


4AA getting hot in 20 seconds 

does the robot work? move, etc.

[SciOlyStudent]

Nope, I actually don't have it assembled yet .  I'll try again once I get everything programmed and the servos on... I did do a little test with the LED and it works fine, but on the other hand, that's only the LED...

[bens]

If your batteries are heating up like that you have a short somewhere on your board.  Try to carefully feel around on your board for a hot spot.  If you have a multimeter, check for a short or low resistance between VIN and ground.  Plugging in servos and sensors will not fix anything (they would just draw more current).

[SciOlyStudent]

I just plugged in my batteries again to check for a short but the batteries got extremely hot so I was forced to unplug them... I felt on my board and could not find any heat (except for the wires connected to the batteries).  Is there any problem that may be occurring with the wires connected to the battery pack?  I do not own a multimeter, is there any other way (besides heat because I can't find any) to check for a short on my board? Thanks for all the replies!

[paulstreats]

how do you have the voltage regulator connected?
Make sure that none of the 3 legs are shorted together, youll probably be best starting from close to the source. Does the voltage regulator heat up?

[bens]

The problem could very well be in your battery holder itself, but without a multimeter it will be difficult to find.  I suggest you head out to Radio Shack and get yourself one; you'll find it quite useful.  I further suggest you leave your circuit unpowered until you locate the problem.

[SciOlyStudent]

I further suggest you leave your circuit unpowered until you locate the problem.

Thanks for the safety warning, but I know not to leave the batteries in if they start getting to hot to touch...

Hey Thanks!!! !!!  I looked at the pins on the regulator and found a small piece of copper sticking out from one of the rings I soldered on to and I found a current running through it!  Plugged in the batteries and no heat was generated, thanks again for all the help!!

[garriwilson]

Hurray!