Major Problem

Hello, I am trying to switch my project power from a regular a USB power connection. to using a battery.... but every time i connect the battery, and monitor the voltage on a multimeter the battery basically is being sucked and drained to 2.5V instead of approximately 9V. battery is not coonected to arduino board but to an lm317 voltage regulator. i checked all connections there is nothing extra.......

P.S. when i switch to regular power from board it runs just fine

Sounds like its pulling a lot of current, standard 9v pp3 type batteries are useless for anything over a few mA.

I am trying to use cell bateries 2016 (size)... yes its a duemilanove.... im trying to use the microcontroller alone rather than the whole board in enclosure..... the LM317 is supposed to be the on board regulator......

is im measuring the current correctly its about 9-12 mA (for multimeter questionably) across the board but its not complete circuit there are more to it than current setup......

all components run fine off the 5V from the board

im measuring the current correctly its about 9-12 mA (for multimeter questionably) across the board

To measure the current, you must place the meter in series, not "across the board".

Why are you using an adjustable regulator? Why not a 7805?

Kyle

It is in series, but its on a bread board everytime i add a dot (node) it seemed to increase...... so i took it from in series from where i plugged in initially to last powered node..........

LM317 because its my first project an not aware of such problems and is what i ended up buying, and is stuck with it now

P.S. further probing suggests a possibility of up 26 mA consumption, :o

26mA is not much... enough to light an LED. So you have the layout of the meter like this:

Battery Pos + --- Red Probe --- Meter --- black probe --- unregulated side of LM317 --- through circuit --- > Battery Gnd

You actually have to break one of the wires going to the battery, and put the meter inbetween. Often times on meters you also have to move the probe to a different post for proper mA or A readings.

using method specified and for clarification on correctness (i connected the black to the same node as the unregulated output which is the v+ for the circuit and the red to the node with battery + and Vin of regulator)

i get about 52 mA and decreasing..... if a 9V battery cannot take this circuit then how do they power game-boys? (honest question)

all that is connected now is an LCD and a microcontroller

ok i thought since its between 5 to 9 i would still be safe… i went with coin for space in the enclosure. would AAA do the trick

PS it lasted 30 seconds…not even 1 minute, 10 is lucky

if a 9V battery cannot take this circuit then how do they power game-boys?

They use a higher capacity batter than you are using.

if a 9V battery cannot take this circuit then how do they power game-boys?

Also, you're not using a normal 9v battery.. you're using 3x 3v CR2016 coin cell batteries...