Are there any issues i should be concerned about if I were to put a voltwatch monitor on my igition of my Fuji 50. being new to gas I left the switch on and killed the battery, Thanks for the input

Totally fine and an excellent idea. Been doing it for years.

I connect a Voltwatch thru a Y-servo lead to the ignition side of the charge switch for the ignition battery. If you are using 2S LiIon, LiIon or A123's, use the Voltwatch that you can set to 6V. It's not gonna help you know the actual voltage level or power remaining with Lithium's. But it's really, really good for 2 things

1. tells you that you've got the ignition switched on - both for safety, and to prevent batteries from getting discharged inadvertantly
2. if you are having a problem with starting or it's running roughly, you can see whether your switch is ok (LED's are flittering), and if for some reason it's dipped into the red because you've lost a cell or damaged the pack.

In my 50cc and up planes that have a clear canopy and open floor (can see inside the fuselage), I locate it so that it's inside the fuselage, but visible thru the canopy. Glue a little balsa plate to one of the formers, just below the canopy. Then stick the Voltwatch to this piece of balsa so it's easily seen thru the canopy.

This modeler used a voltwatch also. Draw your own conclusions.

http://www.rcuniverse.com/forum/m_78...tm.htm#7873884

A Voltwatch is NOT a loaded tester. It only tells you the surface voltage of the pack. It won't tell you anything about the health of a battery pack under load. You need a loaded tester and a battery cycler to do that.

However, a Voltwatch WILL tell you very well, that the ignition is powered on, which is a very, very good thing. And if you started the flight with everything in the green, and you land and everything is in the red, then you know there's a problem! Another option is to use the MPI charge/switch that has the built-in LED's for your ignition. Clip the wire and set it to 6V operation if you are running lithiums.