Vallier Racing

working on some planes this eve and the last time i flew was about 6mth ago. bought a new rx for the plane and installed it turn on the tx and it says 9.7v good has a full charge. plug in the batt to the rx and the servos do there jiggle. go and use the tx and nothing happens. tryen on 2 other airplanes same thing. before this last flight 6mth ago the radio gear had sat for just under 2 years. i;m thinking a bad battery, says good voltage but when i put a input to the radio and ask it to transmit this puts a load on the battery and if it has a bad cell the voltage will drop off. how can i test my tx battery and the tx

kenlowe

My Feedback: (8)

Jet Boy,

I'll ask the obvious question: does the RX type programmed in the TX match the RX you're using. Nothing happens if you try to control a PPM RX with the transmitter set to PCM or vice versa. Ask me how I know.

Was the battery voltage read after a full charge? It seems low, but 9.7V should still work fine.

Good luck with it!

Ken

Vallier Racing

have it figured out the tx pack has a bad cell in it need a new pack

Charlie P.

11.1V on my 9CAP is a good full charge. It's usually 10.9V by the time I get to the airfield. 9.7V is near-nuff dead and time to call it a day. 9.6V is too low to fly. If it drops below 8.5V a warning sounds Put it on charge for 18 hours and see what you get.

Get a good charger/discharger to check batter condition. I have a Triton Jr. that is pretty good, but there are better for less $.

jetmech05

I agree 9.7 is almost dead

K-Bob

My Feedback: (1)

Almost dead? It's a 9.6V battery. I used to fly mine down to 9.4 regularly. Never a problem. Ever.

Charlie P.

Eight cells. 9.6V divided by 8 is 1.2 volts. An Alkaline is 1.5 volts. Your car battery is 13.8V when fully charged and 11.8V won't hardly turn the engine over.

Voltage is not a good measurement of strength but it is what's available. In a battery cell 1.40 volts is strong but 1.20 volts is weak and 1.15 volts is dead. That's why we use expanded scale voltmeters. There's a narrow range of "good" voltage.

jetmech05

A fully charged 9.6 volt battery on a 9C is as Charlie said 11.1 or 11.2 V...same as the 10C.....
I would never fly less than 10.4....it's just too easy to charge either at home or at the field

K-Bob

My Feedback: (1)

That's great but these aren't Alkaline. They are Ni-Cads and they are rated at 1.2V/cell. Most auto cyclers will take them down to 1.1v/cell on the discharge.

9.6V is well within the safety margin.

But that's neither here nor there. Whatever you're comfortable with is the best rating.

j.duncker

My Feedback: (2)

If it is showing 9.7 volts with the tx on the battery is not the problem.

Remove and refit the tx module and wiggle the crystal.

Silly point are you sure you have the correct frequency set up.