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Receiver batteries

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Old 01-27-2013, 05:36 AM
  #26
Su26flyer
 
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Default RE: Receiver batteries


Quote:
ORIGINAL: Wayne22

it depends on the max voltage that your servos will take. Many JR and some Futaba servos are rated at 6 volts max. I've seen one such servo get cooked running an unregulated 123 pack. NiMH have a bad tendancy to drop in voltage under load....I wont use them except in pairs of 5 cells with a regulator.
Since the Nano only weighs 12 lbs fully fuelled, there is no need to get overly complicated with it.

No need to get overly complicated full stop in my opinion
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Old 01-27-2013, 05:48 AM
  #27
3dean
 
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Default RE: Receiver batteries

hmmm is a sensor switch and 2 batts over complicated ? or just common sense ??
i think its a nobrainer

yes my nano was good value 😜
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Old 01-27-2013, 09:09 AM
  #28
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Default RE: Receiver batteries

for your nano. Since it is a small jet you can do the following. Use two switch system with two 1100 mah a123 batteries and you will be fine. Or get a wolverine type switch.

You dont need a power box or anything for a nano just use the two batteries.


Patrick
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Old 01-27-2013, 11:13 AM
  #29
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Default RE: Receiver batteries

"I've seen one such servo get cooked running an unregulated 123 pack."

In that case it would have burst into flames on a 5 cell Nimh straight off the charger.

A123's used to be obtained from 36volt DeWalt packs, but now I think they have changed, in the UK you can buy them from Puffin Models.

Mike
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Old 01-27-2013, 11:19 AM
  #30
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Default RE: Receiver batteries

Yes, you can plug two batteries into any receiver and they are in parallel ... but this is not the same as using a JR/Spectrum PowerSafe receiver, Powerbox or other battery sharing device. Devices intended for this purpose isolate the two batteries so that a shorted cell or similar occurance in one battery can't pull down the bus voltage.
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Old 01-27-2013, 12:42 PM
  #31
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Default RE: Receiver batteries

Quote:
ORIGINAL: gsmarino2000

Yes, you can plug two batteries into any receiver and they are in parallel ... but this is not the same as using a JR/Spectrum PowerSafe receiver, Powerbox or other battery sharing device. Devices intended for this purpose isolate the two batteries so that a shorted cell or similar occurance in one battery can't pull down the bus voltage.
Whoa boy......we busted that myth years ago. Here's one of the better explanations: http://www.hangtimes.com/parallel_packs.html
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Old 01-27-2013, 12:57 PM
  #32
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Default RE: Receiver batteries


Quote:
ORIGINAL: CraigG


Quote:
ORIGINAL: ash 26

I would always go through a regulator like Power Box sensor switch or emcotech

cheers

Andy
Not everybody agrees but many of us have been running A123 batteries without regulators and without problems of any sort. Goes along with the aforementioned KISS principle. It's an individual choice.
+1
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Old 01-27-2013, 01:24 PM
  #33
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Default RE: Receiver batteries


Quote:
ORIGINAL: Su26flyer


Quote:
ORIGINAL: Dave Wilshere

First...there is no such thing as 4.8v operation...I have argued with JR over this for 10 years plus and have only had a straight answer in the last year. 4.8v is a poor description of battery voltage, it means 4 cell. 6v (common Futaba talk) means 5 cell...Ni or MiMH. These are flat voltages and NOT what we fly at. Good 4 cell packs operate between 5.5 and 5.7v, Good 5 cell packs around 7.2v. JR do all their testing on servos and radios at 5.7v....
Most Rx's now are good over a range of voltages right up to 8.4v (2s Li-Po called 7.4v!!) 2s Li-po when charged. So its down the the servos and sometimes valves as to what they will take.
Powerbox realised a long time ago that an optimum voltage for servos and Rx's is between 5.5 and 5.9v

I fly my Nano with a single Digi switch rated at 3A and 5.5v, it has a 2s Li-Po charged to 8.4v and I have digital servos on everything except nose steering and I can say I fly it hard...for landing I have 90 degree flap, Ailerons raised 12mm and rudders spread 15mm to all act as air brake. I have 100+ flights and the Digi switch heat sink gets slightly warm after flight. (how many of you check the temp of your Sensor switch or even Powerbox unit alu heat sinks...this tells you everything about how hard the unit is working.

In this case if they are good NimH (Eneloop) or quality D cells running 5 cells (so 7v plus), I'd stick in a Sensor Switch (overkill) and fly all weekend.
I have Sensor switches in all my CARF Flashes including the 2006 Instruction manual aeroplane, with the same two 2s Li-Pos with hundreds and hundreds of flights...thats rated at 5A

Dave W
Dave Your points about voltages etc are very well made and I would agree that a sensor switch (duel) is a good device. I wonder however if a switch that costs about £70 fits into the bracket of keeping it simple on what was designed to be possibly the most simple RC jet.
Keeping it simple would be a cheap on off switch? One of the budget switches?? simple is not always good...The Dual sensor switch has saved many a model, provides constant voltage to servo and Rx. Simple is a fail safe switch that cannot accidentally be switched off. Its the best option in my opinion and I guess the hundreds we have sold and seen in operation at Jet meets in this country go some way to prove that. There are loads more than the A123 Li-Fe users (which for JR are operating above JR's voltage suggestion-certainly the UK's most popular choice of servo for Jets.)

Dave
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Old 01-28-2013, 12:33 AM
  #34
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Default RE: Receiver batteries


Quote:
ORIGINAL: Su26flyer


Quote:
ORIGINAL: BaldEagel


Quote:
ORIGINAL: StephenUK

Hi guys,

Thank you very much for the information. If I use 2s A123 batteries, Will i be ok to plug these straight into the receiver through a normal switch, without the use of a regulator? the receiver instructions specify an input voltage range of 4.8v - 8.5v and a 'normal rated voltage' of 4.8v? I guess it would depend on the voltage rating of the servos?

Once again many thanks

Stephen
I have been using A123's since they first appeared in the market, this was before they where available to the RC market, I just use them the same as a Nimh battery (except for charging) their off the charger voltage is less than a fresh charged 5 cell Nimh, they do not need a regulator.

Mike
Where does one buy these miracle 123's from. I never seem to see them in normal shops
Electric Wingman!
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Old 01-28-2013, 12:45 AM
  #35
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Default RE: Receiver batteries

I keep it simple by not using a switch.

M
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Old 01-28-2013, 02:47 AM
  #36
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Default RE: Receiver batteries

I happily use JR servos with 5 cell nicad/nimhs, but how do they react to the higher nominal voltage of unregulated A123s? Is it borderline and would be much safer to be regulated? If so, has the A123 got a high enough voltage to drive a 5.9V regulator e.g. powerbox sensor switch?
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Old 01-28-2013, 03:11 AM
  #37
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Default RE: Receiver batteries

Yes, the A123 will drive a Sensor switch, at the end of the day the regulators waste loads of capacity dropping 8.4v down to 5.9v. 6.6v to 5.9v is better!

Dw
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Old 01-28-2013, 03:12 AM
  #38
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Default RE: Receiver batteries


Quote:
ORIGINAL: HarryC

I happily use JR servos with 5 cell nicad/nimhs, but how do they react to the higher nominal voltage of unregulated A123s? Is it borderline and would be much safer to be regulated? If so, has the A123 got a high enough voltage to drive a 5.9V regulator e.g. powerbox sensor switch?
Don't know where you are coming from Harry, a 5 cell nicad/nimhs (7.2volts off the charger) has a higher nominal voltage than a two cell A123 (6.6 off the charger) the powerbox sensor switch has a A123 setting, or certainly the instruction tell you how to set it up with A123's.

Mike
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Old 01-28-2013, 03:19 AM
  #39
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Default RE: Receiver batteries


Quote:
ORIGINAL: BaldEagel

Don't know where you are coming from Harry, a 5 cell nicad/nimhs (7.2volts off the charger) has a higher nominal voltage
Nominal voltage of 5 cell Nickel is 6V, not 7.2V
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Old 01-28-2013, 03:28 AM
  #40
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Default RE: Receiver batteries

Any of my 5 cell Nickel batteries that are down to 6v get charged.

Mike
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Old 01-28-2013, 12:32 PM
  #41
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Default RE: Receiver batteries

Hi guys,

Thank you very much for all your help, much appreciated. I think that given that I want to replace the existing batteries that came with the plane anyway, I will go for 2x Life/A123 batteries using a power box sensor switch. is the attached link the one to go for?

Regards

Stephen

http://alshobbies.com/shop/lookupstock.php?pc=5222
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Old 01-28-2013, 12:43 PM
  #42
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Default RE: Receiver batteries

weldone !!! great choice
yup thats the one
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