I posted in the open radio forum titled "When to quit flying" or something lilke that. I should have posted it here but it relates to when to quit flying based on tx voltage. If you could have a look at it and give me a reply, I would appreciate it.
Thanks,,,basmntdweller

Hi basmntdweller,


Most transmitters, due to design, will have a drop in output power as the battery voltage drops.This is not a proportional drop when using Ni-cad batteries due to the discharge curve of the battery itself. The Ni-cad battery will produce a slight reduction in voltage until the capacity is almost depleted. After that point the voltage will drop off at a very rapid rate.

The 9C transmitter will produce a beeping sound when the battery voltage reaches 8.4 volts. This is a safety feature so that the modeler, who forgets to check his battery voltage, can land his aircraft safely. The aircraft must land as soon as the beeping sound is heard. The modeler should consider recharging the battery when it reaches about 9.5 volts.

I hope you find this information helpful. You can also reach our Futaba support technical team at 217-398-8970, or via fax at 217-398-7721.

Sincerely,
Krysta
Lead Futaba Customer Service and Programming Technician
Also you may want to check our Website at (http://www.futaba-rc.com)