Countryboy

My Feedback: (25)

I can't speak for the FUTABA R6014FS in regards to using A123's, but I can tell you the Spektrum AR9000 has no problem in handling them. Also no problem's using the A123 3 cell on the Jetcat ECU...to date anyway!

Had to lengthen the charge/balance lead on the ECU pack...so snapped these pics before I installed it back in the aircraft.

jseppanen

Hmmm...4,8-6 volts...4 cell NiMH -pack fresh from charger is about or a little over 6V and 5 cell pack nearing 8V. 2S LiFe pack is never over 7.2V and most of the time 6.6-6.7V.

For example in F3B -competition gliders almost everyone is nowadays using a 5 cell Ni -chemistry pack - never seen one or used one with regulator. And yes, they take considerable amps during winch towing. Guys - me included - regularly use 2S LiFe -packs without regs in large gas planes too - amp draw is considerably higher in these compared to our jets. For example my 40% MX2 takes around 700-800mAh per one 8-10min flight. Over 100 flights this year with A123s, no regs neither problems...

Of course servo life could/would be shortend with higher voltage and thus higher speed/amps.

For high quality switches or JR/Futaba receivers even 8V is really no problem in my personal experience. Never blown one or seen someone else have problems with these components due to 'over' voltage.

...my 2 euro cents...and sorry for some offtopic comparisons and pics - this is after all the jet forum...

jseppanen

...no probs what so ever in my use!

And btw my Airworld Gripen - under construction - will get five packs of A123's; 2x 2S 2300mAh for receiver/servos, one 3S 2300mAh pack for P200 ecu, one 2S 1100mAh pack for hydraulic gear system and one 2S 1100mAh pack for lights...keeping chemistry the same for every pack to avoid potential hazards when charging...talk about some leads/charging plugs...

ela

I like to hear that many use the a123 with no regulators. My point compared to a 5 cell nimh or nicd is that they have not the same ability to keep their voltage when things start drawing amps. It is not the voltage that is "dangerous" but the high amp and thereby temperature in the receiver especially. The A123 is not directly comparable to a 5 cell nimh or nicd altough you can see the same voltage when they are fresh.

jseppanen

Not trying to start a fight but I totally disagree! Please explain the "...not the same ability to keep their voltage..." more spesifically if possible. In my mind the abilility of A123's is not the same but a lot better - even in cold weather which we both are familiar with...

ela

We can agree about that. What I ment was that nicd/nimh drops under the recomended 6V as soon as the load increase and therefore the receiver has no problems with it. It is current that produses heat, not voltage.

jseppanen

Ahh ok, I get what you mean! With A123's you indeed get really consistant voltage to rec./servos no matter the current draw - the internal resistance (IR) of these cells is amazingly low...

On the other hand considerable voltage drop under load=inconsistent servo speed and handling. Maybe not noticeable in normal flying? But I would rather wear a t-shirt at 0-10 degrees celsius than fly a high amp draw plane in the same weather with 4 cell Ni -pack...or maybe not...Any colder is normally considered the building season - but you Norwegians don't seem to care

And again to repeat myself - I've NEVER had a problem neither personally seen one with slight, 6-7V, over voltage to servos or receivers...

Edit.

...but have seen several planes crash due to one or more dead Ni -cells in the receiver pack. Of course possible with LiFe's too, no argument with that.

And with LiPos you really can have a disaster - a few weeks ago saw totally burned CompArf 100CC YAK due to charging failure - right cell counts and chemistries selected. Most likely one cell was at the end of its life and the other one in 2S pack didn't like the 8.4V charge. Luckily my friend's car was a couple of metres away so it didn't catch fire, everything else was just a huge mess. Should never charge these inside a plane. Even that is THE reason to go A123...

gooseF22

I have intentionally overcharged the A123, and the Iron corps batteries during testing to over 5 volts. I expected them to blow but the casing held together. They got extremely hot, the end puffed out, and they have a very sharp odor you cannot miss.

I Regularly charge them to 3.75 volts per cell, and as always it bleeds off. Nominal FULL voltage is 6.6-6.8 once the "top" is bled off. Most of the time my 2S packs reside about 6.7 volts when full, after doing a range check or cycling the controls.

I have done alot with these batteries at varying loads. They do depress a bit, but thats ok. Its just different. I have run these batteries at 80 amps continuously. at that ameperage, they depress to about 2.2 volts per cell, but they deliver the goods. Im talking about a 2300 Mah cell delivering 80 amps. Thats extreme of course, but its true. The can handle 60 amps and not heat hardly at all. It 70 they start to heat. When using as a receiver pack, I have never seen less than 6 volts on any spikes even. There is NOTHING out there that can deliver any better performance than that.

I am also running the 1100's in a 6S4P pack....basically its two Dewalt 18 volt drill packs on my trainer delivering max of 60 amps. No sweat...dont even heat. I have an 8S pack that delivers over 1500 watts.

So what Im trying to say, is for receivers, you are not even challenging the pack, and because of that, it delivers smooth, flat voltage at the limit of the wiring you have it hooked to. Its really that simple.

For what its worth, I ran the 1100's until they went flat to 12 volts on the 6S. when I recharge, they held 4044 mah, or 1011 per pack. thats the absolute limit for 1100's. It wouldnt even spin the prop other than one time. However, it powered the flight controls just fine and I landed just fine using the BEC because the current draw is so low.

The power, the quick charge, the safety, the stability, over 1000 charges.....

In my opinion, this is the best. Take that for what its worth, but you have to count flights or milliamps. Nothing new, its just now more important.

Oh, in the spirit of this thread, alot of jets use them now....including mine. I have JR and Hitec servos.

If you feel you need a tiny voltage regulator for little servos, like gear or brakes, get the little spektrum voltage regulator thats' for heli's. it has two inputs and two outputs at 5 volts.

m2c.

goose

Speny

What about A123 (6.6v) on electronic air valves. Most are rated at 4.8 to 6 volts.
Whats your valve setups and any problems?

Sandor if your reading this - what about your 1A valves or the Prolinx (airpower) valves


PS

JSEPPANEN

Where did you get that red smoke? I bet youve been asked a million times somewhere else on this forum site but please tell me / us.

Jgwright

I use Jet 1A valves for up and down and doors and a Jettronic brake valve in my Flyeaglejet Rafale running directly from the A123 cells. In my Swallow I was using an Orbit brake valve again withy A123 cells. No problems with either.

John

jseppanen

Off topic start:

The red smoke oil is the real stuff from these guys (see pic.)...leftovers from a show they performed in Finland summer 2007.

WARNING: unless you absolutely MUST - stay away from this stuff!!! Why? This stuff is nasty! Everything will end up the color you are putting in the tank; your hands, plane, car, carage, smoke oil filling station etc. It's really sticky too and will at least temporarily hamper the performance of the smoke pump if not immediately 'washed' with fresh normal smoke oil - diesel or similar!

Viscosity of these real plane smoke oils is much higher than diesel, kero etc. And if you mix it like 50/50 the smoke won't anymore be red - more like white with a hint of red, not worth it, because it will still make a mess. If you ever come to Finland I'll be glad to give you a 20 litres can of this sh_t. Or wait - I'll give you the can and buy you a couple of beers too...

Off Topic end.

myersflyers

My Feedback: (33)

SinCityJets, Any A123 in stock? Thanks

Speny

Many thanks for that smoke info - seems a dead in the water idea then. Ill let you know if I can make it for those beers though! LOL

Mart

Sorry - back to the topic now ........

ela

Since we are on with direct use of A123 for the receiver:
1. Are there anyone who is using the two cell A123 for rx in combination with G-Booster? I can't find anything in the Boosters manual. Graupner usually sticks to their policy with either 4 cell nicd or 6V regulated.

2. I am using the Futaba 6014 receiver. In my understanding the Spectrum receiver put out max 6V to the servoes. (since theire receivers are rated up to 9 volts they must have a regulatedd output) But I don't think this is the case with Futaba FASST?

Hammbone

My Feedback: (309)

So this thing will tell me how many mah's are left in an A123 pack?

Jim

d_wheel

They work fine Jose. Have been using them on all of my FASST receivers with no problems at all.

Later;

D.W.

gooseF22

no regulated output either. its just a bus (spektrum), just like any other. the receiver electronics can have a 3-10v input. Servo output is whatever goes in.

I saw a guy running a Gbooster 160 with A123 rx packs a few weeks ago. I didnt hear anythng contrary.

ela

Thank you for your answer. Then it's nothing new.