Newbie with dual battery question..?????

[Jason Michael]

I keep reading I should have 2 batteries on my 31%edge540t zdz80.
I have no choke servo and no kill switch on the plane.
I am using the JR X9303 2.4GHZ tx with JR R-921 RX.

I have an extra battery and heavy duty JR switch. 1.)How do I hook it up so I have 2 batteries powering the rx ? That way I will not ever loose power to my rx.
2.) If I lost power to my TX or RX can I kill my engine?
3.) Should I buy a kill switch? Now I just land and turn ignition switch off to kill it. Or I could pull the trim down and kill it.
Like I said I am new to the world of gassers. I am feeling kind of unsafe about my setup or just unsure I guess.

[turbotom123]

Near the bottom of the receiver there is a second power slot. THis is where you should plug in the second switch and battery. THis creates a redundant setup that is almost fool proof. A friend of mine is using the same tx and rx with duralite regulators and li ion batteries. No problems yet. As for the kill switch you can look at the smart fly optical kill units. THese are very popular. Also you could go to radio shack and purchase a small micro momentary switch and wire it in to the positive side of the ignition and activate the switch through a pull cable to kill the ignition. I could be mistaking but i think that ama requires you to have some method of killing the ignition in case of radio loss. Hope this helps.

[sweetpea]

First.......your not being unsafe.

For most gas planes 85in or larger in wingspan....IMAA (not IMAC, not AMA) require 3 ways to kill your plane.

1. switch to ignition battery
2. throttle trim all the way down
3. choke servo or optical kill or something similar

You already have 1 and 2 covered. #3 is a nice to have.....its also not real expensive (about $30-50) and can save you when your plane breaks and you have to fly around at some odd throttle setting until fuel runs out. But unless you fly at an IMAA fly-in you do not require it.

Next---if you want your motor to die when you lose signal

since your using your 9303 2.4.......when you bind you need to set your throttle up so that at idle it is all the way closed. Then once its bound it will look to that setting for failsafe. Now you can adjust your throttle back to a good idle and all is good. When you do this don't use your throttle trim.....I'd use subtrim or something similar. Then check it on the ground by turning your radio off with the plane on (engine not running of course first) If you had a choke servo or optical kill you can accomplish it the same way with those by setting the failsafe to have those move to the off positions.

Remember.....that is not a requirement by any organization to have your motor die at signal loss. Most people either have it die or go to idle. Pros and Cons for both.


Finally for the RX power its simple. Plug one battery into your batt channel and the other battery into one of your empty channels (I'd use a seperate switch for each battery though). If you don't have an empty channel than you can Y it into a used channel. You could also get a power expander or battshare. If your using LIONS remember each battery needs its own regulator or a regulator that can handle 2 batteries (like the Turbo Reg)

[Jason Michael]

Guys, Thank you for all the very helpful info.

It is nice to know that it is that simple to hook up 2 batteries.
Nice to know the plane is setup safely for my first gasser.
I have been looking at the power expander and turbo regs as well.
I have a spare ZDZ 80RV with pitts style smoke muffler. I think I am going to throw that in a SD Models Yak from Bill at Troy Built Models. Though it is only an 80cc I am going to overkill it with electronics and get some practice setting up a very safe system. Eventually I plan on moving to 40 and 50% aircraft. So the electronics will be put to good use.