[zdsh13]

Originally Posted by volksman

oh and by the way i think the power boards and all the junk associated with them is to catch your wallet before it gets crashed back into your pocket. the huge battery packs are for what im not sure the yak has all the same junk as the most have in it and could fly with an 1100mah hr pack for well over an hr on the reciever.

Your right mostly... back in the late 80's early 90's I'd fly with 500 mah nicd Rx packs, but I only had 4 - 5 analog servos. I would easily get 6 flights and still have some juice left in the pack.

Now days with high performance power hungry digital servos... whether you spend the extra money on a power safe receiver or use the receiver you already have and spend $225 on a smartfly power board it still works out to spending money. I know I would rather spend an extra $200 on a power board or power safe reciever than risk a brownout and lose a 3500 - $4500 RTF airframe over an additional $200 (5%) expenditure.

Each to there own but I won't use less than 2 A123 Rx batteries typically 2300 mah each. I don't do serious 3D so I don't have the desire to cut every oz of weight to maximize my power to weight ratio, I believe in keeping an airframe light as the flight charactoristics are better....but there are some safety margins I don't want to trim and batteries is one.

[volksman]

this one is for zsdh or the last post anyways. the yak in mention has no power safe nothing just all digital servos and a single 2200 a123 flight pack straight in to a futaba brick pcm reciever.22 awg wire will handle 10 amps the stalled hitec servo common aileron one i dont remember the model number. after a crash with a wonderful spectrum reciever, the two servos went puff at 4 amps in a stalled test, wires showed no signs of being deformed from heat. the recievers themselves will take around 5 amps. most current draw again from a data logger is drawn from taxi and take of with the resistance of ground and no lift on the surfaces. the gadgets are sold to make money good ideas on paper great for the guys who need the latest greatest. reduntant are ya sure it is really redundant?

[zdsh13]

Originally Posted by volksman

the yak in mention has no power safe nothing just all digital servos and a single 2200 a123 flight pack straight in to a futaba brick pcm reciever.22 awg wire will handle 10 amps

From what I've read 22AWG is rated for 7 amps continuous, but most manufacturers rate the connectors at 3 - 5 amps.

Originally Posted by volksman

the recievers themselves will take around 5 amps. the gadgets are sold to make money good ideas on paper great for the guys who need the latest greatest. reduntant are ya sure it is really redundant?

This just prooves why you are better suited to go to a power safe receiver or power board on a larger airframe ( 50cc and up).... 5amps is a bottleneck if the 22AWG wire handles more than 5 amps....

What do you think happens to the voltage at the receiver when you draw max amperage and the wire or connector becomes the bottle neck... possibly the voltage sags at the receiver and you experience a brownout.... possible crash... I would bet that the airframe loss greatly exceeds the cost of a power board or power safe receiver....

[volksman]

an a123 will produce 75 amps at 6.6 volts for close to two minutes, the voltage doesnt sag but will create nice orange flames, rethink your powersafe stuff. brown out doesnt happen with a123. all the spectrum crap is just that. voltage with a given resistance will cause a certain current to be drawn high resistance low current, simple.reciever servos switches etc channel the flow of electrons (current)anywheres a lower path of resistance is created more current flows simple so look at what will happen you have a short in a power expander that is capable of channeling 50 to 75 amps.

[nikole]

Originally Posted by jdiprofio

Thanks so much for the info...I think I will either use a 1100mah Lipo or 4 cell Nickel Metal H on the ignition. Save the headache for the few ounces it will add.

I'd be careful with the lipo on the ignition Joe as the voltage may be too high. If you're going to use the lipo, use a 6 volt regulator.

[jdiprofio]

Thanks for all the info guys. I am going with A123 for Radio and Servos and a 1100mah nickel metal on ignition. No fancy boards to fry. I do have an optical shutoff coming...that will be about as fancy as I get.

Cheers Joe

[Guest]

I'm gonna try a Tech-Aero Ultra IBEC in my DLE 20 Ultimate to get rid of the ignition battery altogether and you can run 6.6 as it will step down the voltage delivered. An option for you to look into as it also does away with the opti-kill as it performs that task as well. One less switch too.

[FastnLow]

Originally Posted by revy

i'm gonna try a tech-aero ultra ibec in my dle 20 ultimate to get rid of the ignition battery altogether and you can run 6.6 as it will step down the voltage delivered. An option for you to look into as it also does away with the opti-kill as it performs that task as well. One less switch too.

make sure there charged!!!

[VA6WGO]

Originally Posted by jdiprofio

Thanks for all the info guys. I am going with A123 for Radio and Servos and a 1100mah nickel metal on ignition. No fancy boards to fry. I do have an optical shutoff coming...that will be about as fancy as I get.

Cheers Joe

Use a 4 cell Ni-Mh instead of 5. A 5 cell fully charge is about 6.8V and most ignitions don't like run any higher than 6V.

The 4 cells Ni-Mh 1100mah would be a great choice since these will be around 5.6V when fully charged.

Cheers,

Will

[Guest]

Originally Posted by FastnLow

make sure there charged!!!

HAHAHAHA...put a couple undercharged planes in and you get ribbed forever! They're LiFe's, not NiMh....