Rx bat. amps needed for 1/4 scale.
03-14-2006, 02:11 PM
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Rx bat. amps needed for 1/4 scale.
I have a 1/4 scale giles I am finishing and need to know how big of battery to use for the Rx. I will be using 5 high torque servos and 1 standard. I was looking at 2700mah or maybe 3300mah NiMH. What is the somewhat cheapest and lightest set up? Appreciate the help.
Alex.
Alex.
03-14-2006, 02:53 PM
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RE: Rx bat. amps needed for 1/4 scale.
The batteries you listed will give you a good amount of flights. It all depends on what you do with the plane each flight, and how long each flight is. Those batteries would be the cheapest, but not the lightest. Lighter will cost a little more, and you can use L-Ion batteries. Fromeco makes great betteries. Not much more expensive than NiCads or NiMh, but you will need to buy a charger. Scott
03-14-2006, 03:18 PM
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RE: Rx bat. amps needed for 1/4 scale.
I myself would run 2100 mah 6V Nickel metals. The cells are AA size so the weight will be minimal. I don't see any advantage to lithium here. A lithium 2700 mah battery and regulator will actually weigh more than the 2100 NiMetal. The 2100 should give you plenty of flight time as you arent running any ganged servos. On my Midwest 202 I ran 5 BB standard servos with a 1000 MAH nicad and was good for 4 flights.
Shawn
Shawn
03-14-2006, 06:11 PM
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RE: Rx bat. amps needed for 1/4 scale.
I got to agree with rcblimppro. I said exactly what I was thinking. I run 2700 6V nimh on my 100cc and never have to worry about anything.
Sean
Sean
03-15-2006, 03:41 PM
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RE: Rx bat. amps needed for 1/4 scale.
ORIGINAL: rcblimppro
I myself would run 2100 mah 6V Nickel metals. The cells are AA size so the weight will be minimal. I don't see any advantage to lithium here. A lithium 2700 mah battery and regulator will actually weigh more than the 2100 NiMetal. The 2100 should give you plenty of flight time as you arent running any ganged servos. On my Midwest 202 I ran 5 BB standard servos with a 1000 MAH nicad and was good for 4 flights.
Shawn
I myself would run 2100 mah 6V Nickel metals. The cells are AA size so the weight will be minimal. I don't see any advantage to lithium here. A lithium 2700 mah battery and regulator will actually weigh more than the 2100 NiMetal. The 2100 should give you plenty of flight time as you arent running any ganged servos. On my Midwest 202 I ran 5 BB standard servos with a 1000 MAH nicad and was good for 4 flights.
Shawn
When I set up my 29% Extra with 5 digitals (plus throttle) I used two 1200 Nimh's so as to have more load carrying capability in the plug. Is that overkill or could I switch back to one 2000 Nimh with 22 guage wire and feel confident? Somewhere on RCU I read that a single lead is only good for 3 amps of draw and that is why I went for two batteries.
What thinks?
03-15-2006, 04:12 PM
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RE: Rx bat. amps needed for 1/4 scale.
I would stay with the setup you have. The original post states 1/4 scale 202. That airplane would be around 72" span 10 to 12lbs and powered by a 1.2 to 1.5 glow motor. For your 29% Edge your setup looks good, I assume you are running a 50cc gas motor that shakes more than a large glow motor. Oddly enough for the most part with a big gasser the most amps your system will draw is while it is on the ground with the servos fighting with the engine vibration to hold the control surface in place.
Shawn
Shawn
03-15-2006, 06:49 PM
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RE: Rx bat. amps needed for 1/4 scale.
Think about the 1800 Kan pack.......
Quote from Hangtime Hobbies who are a good source for info and make good packs
Here's an impressive little NiMH cell that can meet high drain ignition and digital servo demands without a significant voltage drop while loads are applied. This is the same physical dimensions as the Sanyo 2150 ' 4/5 A' NiMH and less than half the internal impedance! Lower impedance cells deliver more useable capacity under load for longer flying times in high drain applications. This makes it an outstanding choice in Heli and smaller IMAC/3D applications where robust power, low weight and high capacity is mandated by agressive servo, gyro or ignition loads.
Finished pack weight inc connector: 6.3oz
Internal Impedance: 7 mOhms
Finished pack weight inc connector: 6.3oz
Internal Impedance: 7 mOhms
03-15-2006, 07:24 PM
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RE: Rx bat. amps needed for 1/4 scale.
ORIGINAL: rdb127
If you are running say a 2100 NIMH on a 17 lb airplane, will the one power lead will it be enough to hold the amperage of the servos without toasting the power lead?
When I set up my 29% Extra with 5 digitals (plus throttle) I used two 1200 Nimh's so as to have more load carrying capability in the plug. Is that overkill or could I switch back to one 2000 Nimh with 22 guage wire and feel confident? Somewhere on RCU I read that a single lead is only good for 3 amps of draw and that is why I went for two batteries.
What thinks?
ORIGINAL: rcblimppro
I myself would run 2100 mah 6V Nickel metals. The cells are AA size so the weight will be minimal. I don't see any advantage to lithium here. A lithium 2700 mah battery and regulator will actually weigh more than the 2100 NiMetal. The 2100 should give you plenty of flight time as you arent running any ganged servos. On my Midwest 202 I ran 5 BB standard servos with a 1000 MAH nicad and was good for 4 flights.
Shawn
I myself would run 2100 mah 6V Nickel metals. The cells are AA size so the weight will be minimal. I don't see any advantage to lithium here. A lithium 2700 mah battery and regulator will actually weigh more than the 2100 NiMetal. The 2100 should give you plenty of flight time as you arent running any ganged servos. On my Midwest 202 I ran 5 BB standard servos with a 1000 MAH nicad and was good for 4 flights.
Shawn
When I set up my 29% Extra with 5 digitals (plus throttle) I used two 1200 Nimh's so as to have more load carrying capability in the plug. Is that overkill or could I switch back to one 2000 Nimh with 22 guage wire and feel confident? Somewhere on RCU I read that a single lead is only good for 3 amps of draw and that is why I went for two batteries.
What thinks?
I am building a 32% QQ 102" Yak and will have 4 power leads going into the receiver - 2 leads off of each Fromeco regulator.
03-15-2006, 10:19 PM
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RE: Rx bat. amps needed for 1/4 scale.
Thanks guys. I currently have 2-2000 mah nimh's on it but was going to switch out to the 1200's when I put the plane on a CF diet.
The two 2000's still had 6.4 volts after about 8 12-14 minute flights. Had to stop cause the Futaba 9CAP had drained down to 9.8v my personal cutoff. Will upgrade that 700mah to around 1600 nimh as well.
The two 2000's still had 6.4 volts after about 8 12-14 minute flights. Had to stop cause the Futaba 9CAP had drained down to 9.8v my personal cutoff. Will upgrade that 700mah to around 1600 nimh as well.
03-18-2006, 10:12 PM
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RE: Rx bat. amps needed for 1/4 scale.
I would use two battery packs and two switches as they give you redundancy. I have seen too many models die through a faulty switch, connection or a crook cell (this is especially applicable if you only use a four cell pack)
The weight penalty is minimal as you can use lower capacity (ie lighter)cells.
Checking battery voltages in between flights should be mandatory and will ensure you notice if you have lost a cell or if a pack is going flat.
The weight penalty is minimal as you can use lower capacity (ie lighter)cells.
Checking battery voltages in between flights should be mandatory and will ensure you notice if you have lost a cell or if a pack is going flat.
