Who using A123 batteries?

[gareth.ky]

	Quote: Originally Posted by Hammbone
	If you don't need to run more than one servo per channel, you're fine with the 9100. If you think that 2.4Ghz is immune to rf noise, you're mistaken. I think long lead line matching has to do with current flow, not servo matching, but to be honest, I'm not really sure what it is. A Power Expander will isolate a bad battery or indicate a bad connection. True, these are not big things, but little extra features that I don't mind having. Jim

That's useful. The Powersafe is supposed to offer isolation also but I haven't tested it (e.g. short one side of the Rx). If the Rx experiences momentary low voltage all of the receiver lights will blink when the thing comes back online. It has a light for each power lead so you can tell that each battery is hooked up and working.

It doesn't have a way to tell you that a single pack's voltage went too low. E.g. if you unplug a pack and plug it back in that's a non event as far as the Rx is concerned.

It doesn't have a way to signal you (external LED or speaker) while the airplane is in flight that a power system issue has occurred. But I haven't seen a power expander that does.

[decoy26]

[quote=Judge;533748]Well, there may be others doing that, but I am not. I fly Futaba radios. I use a 14MZ and do not use additional servo matching devices, power distribution equipment, or anything beyond good batteries, large gauge wire and low loss plugs.



Well, to be honest, between my radio, receiver and power expander I have a total of $500.00 invested. $2200 for a 14MZ seems a slight bit steep but I guess it is worth it considering what you get. I will stick with my un-neccessary setup.

[aviti]

Judge - Are you saying that the heavy guage power connections are not necessary? Would you run 14 high torque digitals with 2 battery leads going into your receiver with standard connectors? No? Maybe 4 standard battery connectors going into your 14 channel receiver. That leaves 11 open slots for servos. Where do you plug in the 3 remaining servos? Matchboxes? Power expanders? Y connectors? You might be able to say powersafe receivers are not necessary, but to say they are just marketing hype is nuts.

If Futaba comes out with their own version of a powersafe receiver, will you not use it?

[Judge]

No, what I am saying is that IF you use heavy gauge wire, good connectors, and dual battery set up then you have done a good deal towards getting the most from your power system.

When running a lithium set up I use Deans connectors between the pack and regulator, and heavy gauge wire from the battery to the regulator. Then use bigger wire (18 or 20) from the regulator to the RX. Using dual packs halves the current load on each pack compared to a single pack.

EMCOTEC did a cool thing a few years ago. They wired up a 14 servo aerobatic plane and recorded in flight current loads. Peaks of 20 to 30 amps were measured during consecutive snap roll sequences. These were on the order of 20 millisecond transient events. Normal load ran around 3 to 5 amps.

So in this case each pack would see 1/2 that load. So say 2 to 2.5 amps normally and maybe 10 to 15 amps during extreme loads during snaps, etc.

This is borne out in my measurements looking at my average current consumption for giant scale planes. Usually works out to about 3 to 4 amps average. Yes, the peaks are higher, but they cannot be substantially higher or longer lived or they would raise the average.

So in the end I think we base our design of power delivery systems on faulty data. We "think" we have higher loads and greater demand than we do in fact have. At least based on the recorded data I have seen and my own measurements.

Our normal servo plugs are rated at 3 amps. That is NOT the maximum amperage they can take. That is the amperage that will not result in a temperature increase under a constant load.

I just like to keep things simple with as few components as possible. Personally I cannot perceive any difference in performance doing simple as opposed to complex. But the perception is that you must have all these things to have an optimal system. I think that is more perception than reality. But I am also in the minority in this thinking.

[Sukhoi08]

Maybe I need to be kissing up to Team Futaba. I fly JR but wouldnt mind switching for one of the new radios. I use matchboxes in one of my 33% and y harnesses in my other 33%. You guys have me worried. I dont think my 9303 FX radio can individually link servos, so this is why my planes are set up this way. Its starting to sound like my chit is all wrong + outdated. Regardless, I think i might just leave my planes alone. I'll order the new QQ 101 yak when the Futaba guy shows up with the radio and rx.

[Judge]

	Quote: Originally Posted by aviti
	If Futaba comes out with their own version of a powersafe receiver, will you not use it?

Not unless I was convinced that there was a reason to do so. Right now, I am not convinced.

[Scott Gerber]

	Quote: Originally Posted by Sukhoi08
	Maybe I need to be kissing up to Team Futaba. I fly JR but wouldnt mind switching for one of the new radios. I use matchboxes in one of my 33% and y harnesses in my other 33%. You guys have me worried. I dont think my 9303 FX radio can individually link servos, so this is why my planes are set up this way. Its starting to sound like my chit is all wrong + outdated. Regardless, I think i might just leave my planes alone. I'll order the new QQ 101 yak when the Futaba guy shows up with the radio and rx.

Red is purddier than Orange.....


Scott

[aviti]

	Quote: Originally Posted by Judge
	Not unless I was convinced that there was a reason to do so. Right now, I am not convinced.

Well I can't imagine what could be more simple than 2 batteries going directly into your receiver with heavy gauge wires without a switch (and not having to plug into unused servo ports). You say you like simple, what's not simple about that?

[Sukhoi08]

well my planes have match boxes and y-harnesses, so i guess it makes sense its outdated as well.
Your right scott, I'll stick with red.

[dick hanson]

	Quote: Originally Posted by Judge
	No, what I am saying is that IF you use heavy gauge wire, good connectors, and dual battery set up then you have done a good deal towards getting the most from your power system. When running a lithium set up I use Deans connectors between the pack and regulator, and heavy gauge wire from the battery to the regulator. Then use bigger wire (18 or 20) from the regulator to the RX. Using dual packs halves the current load on each pack compared to a single pack. EMCOTEC did a cool thing a few years ago. They wired up a 14 servo aerobatic plane and recorded in flight current loads. Peaks of 20 to 30 amps were measured during consecutive snap roll sequences. These were on the order of 20 millisecond transient events. Normal load ran around 3 to 5 amps. So in this case each pack would see 1/2 that load. So say 2 to 2.5 amps normally and maybe 10 to 15 amps during extreme loads during snaps, etc. This is borne out in my measurements looking at my average current consumption for giant scale planes. Usually works out to about 3 to 4 amps average. Yes, the peaks are higher, but they cannot be substantially higher or longer lived or they would raise the average. So in the end I think we base our design of power delivery systems on faulty data. We "think" we have higher loads and greater demand than we do in fact have. At least based on the recorded data I have seen and my own measurements. Our normal servo plugs are rated at 3 amps. That is NOT the maximum amperage they can take. That is the amperage that will not result in a temperature increase under a constant load. I just like to keep things simple with as few components as possible. Personally I cannot perceive any difference in performance doing simple as opposed to complex. But the perception is that you must have all these things to have an optimal system. I think that is more perception than reality. But I am also in the minority in this thinking.

Opinions--
when the servos especially the latest greatest high torque types, do rapid direction reversals - the power spikes are pretty high- very short duration but high peak.
High peaks rapidly input, will create heat - and as the components heat , their ability to perform goes down - waaaaay down.
To be a bit pointy fingered - average consumption is like drowning in an average of 1" of water - meaningless for the new computer radios
You don't have to believe this - but it is pretty std electronics 101.
the good ol crimped pin stuff designed over 20 yers ago is simply not up to the task for these aplications.
Emcotec's test likely did not show peaks such as we can see today-- unless they had some pretty fine equipment .
I fly electric stuf as do many now and the peak loads we can make are sometimes very surprising - you can weld with less current---
The new rx with direct batt plug in -is about as good and simple as it gets- in bypassing the problems which can exist. -
I don't care who makes it - the idea is spot on.
personally I wouldn't use a reg in the circuit if you paid me -

[Judge]

	Quote: Originally Posted by aviti
	Well I can't imagine what could be more simple than 2 batteries going directly into your receiver with heavy gauge wires without a switch (and not having to plug into unused servo ports). You say you like simple, what's not simple about that?

Actually in most of my gliders I do not use a switch and simply plug into the RX directly. Never been an issue in many years of doing so.

Bottom line is that people should do what they feel most comfortable with. I prefer to go towards the less complicated end of things whenever possible.

[Judge]

	Quote: Originally Posted by dick hanson
	To be a bit pointy fingered - average consumption is like drowning in an average of 1" of water - meaningless for the new computer radios You don't have to believe this - but it is pretty std electronics 101.

Well OK then. Like I said, people should do what they feel comfortable with doing. And I guess I'll have to take some remedial electronics lessons.

This is like religion, everyone is on the bandwagon and nobody wants to hear otherwise. That is pretty basic marketing 101 BTW.

The EMCOTEC test was done using JR 8411 servos, fairly big power hogs. What I would really like to see is some in flight data showing wire temps, because that is where too small or overloaded wires will really show up.

[dick hanson]

	Quote: Originally Posted by Judge
	Well OK then. Like I said, people should do what they feel comfortable with doing. And I guess I'll have to take some remedial electronics lessons. This is like religion, everyone is on the bandwagon and nobody wants to hear otherwise. That is pretty basic marketing 101 BTW. The EMCOTEC test was done using JR 8411 servos, fairly big power hogs. What I would really like to see is some in flight data showing wire temps, because that is where too small or overloaded wires will really show up.

One last observation- it ain't the wires - it is the connectors and the resistance which builds at the junction of the wire and the connection. I have measured this - and suffice to say it is a rather iffy number - but as a generality MUCH hotter than the typical wires to which the connectors are attached.
I did this using my good ol simple 1157 tail light bulb apparatus the reason for th iffy measurement is that the connections and THEIR subsequent connections (male to female) ar not consistant.
This is where the flashing lights on the new DSM2 rx can really save your hide - - a loose/ poor connection reads the same as a bad batt.
I have been weeding out old , poor fitting male /female connectors - more cheap insurance.

[robertp17]

Slightly off topic here but does anyone know if you can use a123 on an older powerbox 40/16? I recently purchased a plane that came with it and it has 2700mah sanyo ni-mh packs that I want to swap out with my a123's but the powerbox says use only 4 or 5 cell nicad or nickel medal. Im sure this thing was made before a123's came out so im wondering if it would be ok to run them.

[dick hanson]

call em-- but A123 --the real ones - can be used as if they were simply incredibly good 5 cell NiCad packs same voltage operating parameters .
charging and discharging are of course, different