lenough

I have a Futaba 9C that I converted about 2 1/2 years ago to 2.4 with the Hitec Module. I converted all my receivers to 6 and 7 channel receivers on my old planes. Last year I started using the 9 channel on gas planes with 6 cell NIMH Batteries. Minimum MAH on the receiver packs are 2500 MAH. I noticed that sometimes when moving the sicks there will be an occasional blip of the blue light on the transmitter module and a single beep. Batteries are new and fully charged. I checked them after this happened. There is no loss of control and range checks are fine.
I'm wondering if this has something to do with the use of 6 cell packs or is it something I should be concerned about?

Thanks,
Lee

A.T.

Quote:

ORIGINAL: lenough I have a Futaba 9C that I converted about 2 1/2 years ago to 2.4 with the Hitec Module.
I converted all my receivers to 6 and 7 channel receivers on my old planes. Last year I started using the 9 channel
on gas planes with 6 cell NIMH Batteries. Minimum MAH on the receiver packs are 2500 MAH. I noticed that sometimes
when moving the sicks there will be an occasional blip of the blue light on the transmitter module and a single beep.
Batteries are new and fully charged. I checked them after this happened. There is no loss of control and range checks are fine.
I'm wondering if this has something to do with the use of 6 cell packs or is it something I should be concerned about? Thanks, Lee

"I noticed that sometimes when moving the sicks there will be an occasional blip of the blue light on the transmitter module and a single beep."
Battery/switch harness/Lead problem as above indicates the voltage is dipping below default
LBW when battery is loaded. Reason should be ascertained as in a high load situation (diving turn)
lack of voltage could cause lack of response and may incorrectly be taken as a signal failure.

No mention of cell size, nor number of servo and type. There is much differenceincurrent draw between
older models with 3<4 standard servo andcurrent largermodern GPmodels with 5+ high power servo.

"6 cell NIMH Batteries. Minimum MAH on the receiver packs are 2500 MAH."
Optima Transceiver & Minima (RX) - Voltage Input Limits.-
" "Optima voltage requirements are 4.8-7.4v being the nominal value of a 2S Lipo.
Charged 6 cell NiMH is over 8.4, is a switchmoderegulator in use?
given that high voltage servo are being usedor current draw will bevery much higher.

If 6 cell is a typo andactually a 5 cell pack (nominal 6v) and the cells are AA,
it is quite possible thatunder load the battery is dropping below the preset default. This
as NiMH AA are not good under load. The highercapacitye.g. 2500 MAh are less able to
handle loads than says1300 MAh, being reasonmany choose to use sub C cellsas used incar packs.
The lifespan of NiMH is also considerably less than the older NiCD, especially if fast charged.

Alternatively, if 6 cell is correct and you have reset the default warning from the auto 4 & 5 cell setting:
Optima Transceiver (RX) - Low Battery Warning settings for both Spectra 2.4Ghz module.
the default setting may need tweaking.

Good reading:
. AFHSS - Warning Beeps Aurora 9 & Spectra 2.4Ghz Module - Interpret & Manage the Independent Alarms.
. Aurora 9 - Warning Alarms Battery types, Voltage Level Interpretation & Consumption.
. Optima Transceiver (RX) - Low Battery Warning settings for both Aurora & Spectra 2.4Ghz module.
Adjustable LBW Voltage Alerts V1.07 up (not available V1.04<06).
. Optima Transceiver (RX) - Battery set up for Nitro/Gas models- caution re NiMH.

Alan T.
Alan's Hobby, Model & RC FAQ Web Links

lenough

Thanks for the reply. Actually it is a 5 cell all double a batteries. Sorry about the typo. Batteries are brand new.

2 of the planes have Hitec 645MG and the third has HD Power 9150MG Digitals. Each plane has 6 servos.

A.T.

As above, 2500MAh packs have high internal resistance and quite likely to fail under the load of those servo, especially if brand new and not cycled at least three times. Would suggest at least sub C NiMH for that application, or as a minimum safety measure, run dual battery packs
Optima Transceiver (RX) - Dual or Multiple Batteries may be installed - Avoid Brownout & Add
Redundancy, even one for each servo.

Following may also be of interest:
Aurora 9 - Battery is not charged. Charge before first use so as not to damage battery.
extract
"2. NiMH do not reach full capacity until after at least the third use (charge).
3.NiCD were reasonably forgiving in the event of overcharge / overdischarge / hard knocks but NiMH are not. Majority of NiMH cells have a shorter life span thanwe used to expect of NiCads, best never to exceed 1c or one hour charge rate.
4. Black wire corrosion is just as much if not more evident in NiMH than was experienced with NiCad.

When Nickel-Metal Hydride (NiMH) was introduced in the early 1990s, much was made of its memory-free status.NiMH do suffer from crystal build up also known as "memory" but to a lesser extent than NiCd. No proven research is known that specifies best maintenance except all concur that repeated cycling of NiMH is not recommended because of the shorter service life.
NiMH were introduced solely to satisfy the EU "Greenies" as under the changed CE regulations, it was to become to expensive to continue with the supply and then subsequentreturn to anddisposal by the supplierof thepoisonous NiCD cells. NiCad are still allowed for use by emergency & medical services in lieu of NiMH. "

Alan T.

JIMF14D

You are getting the low voltage alarm probably. Check servo/surfaces for binding and if things are good then your battery is weak, low charge or too small for you system.

Jim D