Futaba 9cap super and nimh

[Tyler6777]

I have a 9 cap super and have a hidramax 1650 nimh in it.After about 20 minutes my battery drops to like 10.3 from 11.1 volts. does this sound about right or is it dropping pretty fast . With this I would be lucky to get an hour of use before it went dead.It just seems like it is dropping fast to me.The battery is about 4 months old.Does running PCM on it drain it quicker or something.Thanks Tyler

[BarracudaHockey]

Turn it on, extend the antenna and leave it sit till you get a low voltage alarm, I think you are going to see its a while.

The battery will drop fairly quickly then level off, hold that voltage range for quite some time then drop off quickly at the end.

pcm/ppm has no bearing on battery consumption, the synth modules to draw more power than standard crystal based modules.

[Gunner]

Tyler, I just purchased a 2400 mAh battery from NOBS batteries for my 9CHP. That battery lasts about 8-10 hours before it needs a recharge. So now I have the new battery that I use in the radio plus the original battery that I keep charged as a spare. The 2400 is a NiMH which doesn't need recycled. Just a thought.

[Skiddz]

I've got a 2700mah NiMh from NOBS in my 9CHP. Initial voltage shows at around 11 volts, then drops to a tick over 10 and stays there for hours and hours. I'd estimate 1 charge lasts about 10 hours of flying with plenty of reserve left. I recharge once the Tx shows about 9.7 volts on the screen.

[Phaedrus]

FYI, here is a discharge curve I did for a 1,600 mAh NiMH in a 9Z TX. WHile the absolute voltage numbers may be a bit different, the shape of the curve will be similar. Point being that a drop like you are seeing is not abnormal.

http://www.scaleaerobatics.org/downloads/9ztx.pdf

Also remember that TX battery voltage does not effect the operation of the TX, until it goes dead that is!!