Torqued-Up

My Feedback: (16)

I've been running Li-Poly batteries on all my gassers for over a year... I just make sure that I have adequate foam padding around the batteries... No problems, so far... As Maudib stated, some Li-Poly's have a much higher burst rate than Li-Ion's, which is why I'm using them...

Bosshossv8

My Feedback: (10)

I have seen aLOT of stupid things happen at our public field, but not that one. LOL.

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Maudib,

I always enjoy technical help from someone with as much experience as you have, it sparks nothing but good technical reasoning, thought. It does everything to further other peoples knowledge, and I think this is one of those times. However this was not intended to be a Electronic forum, but this tread meanders so much becaus eof the quality of the plane ,and the tecnical perfection it calls for.

But I post this question to you , based your post, I am always interested in enlightenment.

I was unawre of the 4.6 amp max drain on a Li-ion round cell. Since the reg is rated at 10amp, and could out draw the cells, failure is possible if not using the 4800 4 cell pack. IF the 4.6 amp max draw is correct. WOW.

I have tested with an amp meter , my plane draw, pushing on surfaces, and never got higher than 7 amps....I was getting worried about stripping the serovs. An Eagle Tree system to record the draw would be a real eye opener.....eh?? I am now curious.

As far Li-polys in a gasser, .....a busted myth in my book, vibration is elimnated with proper mounting, fires are an extreme rarity, all user induced. I can live with the risks.

I am curious about the max draw from a single Li-ion Frome 2400 cell. I run 3 3amp rated leads into my receiver, the reg is rated at 10, I pull 7 static under stress, ..........time for a bench abuse test on round cell.


This is what I like about the forums.

Bosshossv8

My Feedback: (10)

Maud,

I did a little reading over Fromeco, I cannot believe I missed the fact of 4 amp max draw on the cells......I thought it was much higher.

I agree , pushing the limit on the cells is a gamble. One I am not going to take anymore. I am all about risk management. (except with my flying, Ha!!).

But interesting enough, the Reg is rated at 10amp ....the 4800 is rated at 8...so the 5 digis at 10 amp draw in blender is pushing them as well, according to the , in my opinion, conservative spec.

Lots to consider.....I love this hobby. I am currently flying a 3D 1.60 glow plane on a Li-poly 2100 ....just to test it's reliablity. So far so good. The current capability of the Li-polies is now going to be the greater reward it seems.

Eagle tree here I come. Need real time data......I love this hobby.

Maudib

My Feedback: (51)

BossHoss,

I understand and not meaning to correct... just to balance info. Someone may not research the discharge rate on these lions and lose a plane over it... worht the post.

Full specs on the 2400 cells are here:

http://www.lgchem.com/upload/product...ry/18650a2.pdf

Page 2 lists Max cont. discharge at at 4600mah (4.6 amp) the 2600 cells are listed at 4.8 amp...


Again... it most likely will work just fine... BUT it is at the high end of the rating of the cell and could contribute to pack failure... if for no other reason than that I avoid a single 2400 mah pack for receiver... 4800's are my choice for 50cc and above.

On the Lipoly issue... I'm still holding out. The manufacture of the VERY thin metal tabs on the cells are my concern... yet they quality of these assemblies are pretty darn good. For the weight savings... on smaller planes... maybe it's worth it to me.

But now we are in the realm of personal preference and confidence levels.

Maudib

My Feedback: (51)

It's a matter of cont. vs. peak... On a 2400 your continuous draw is closr to the max rating... it's fine to peak most cells for short bursts (i.e. blenders, etc) without any real significant harm... Pop 10 amps and you are hitting 200% peak over rating.

But with a 4800 you have more headroom, create less stress/heat on the packs, and can easily pop 10 amps on a 4800 (25% peak over rating)

The numbers just look better.

Edge

Actually boss, I wasn't referring to any generalalities. From what I have seen, when all your systems work properly, that's when you are more likely to crash.

wgeffon

My Feedback: (4)

Hmmm.
I dont know. Simple has always worked.
Batteries, switches, Li-ion's, regulators, RX, servos, gas it , flip it, fly the piss out of it.


(IMO)
The guys who overthink the set ups are the ones who miss the big picture.

romanrc

I saw a blue edge from Chris, flyed in the Nashbro 06, this will be the new 50 cc????

romanrc

http://www.the******************.com...ro+06&start=80


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Edge

Mr. Wgeffon, if someone overthinks it, will that change the balance in anyway?

Maudib

My Feedback: (51)

I think this is a prototype of a yet to be announced entry into the awesome electric line following the great success of Extra 300E and now new Yak 54-E.

45" or so...

ckoerner

My Feedback: (2)

Boss,
Darn, I have been flying my EF Yak now for 2 summers on the Fromeco's. Never a problem. Guess I will have to get rid of them now.
How much battery power to do a knife edge loop into the ground? J/K! Boss quit thinking and fly. The Fromeco's will be fine.

wgeffon

My Feedback: (4)

Yes.
It will shift the CG slightly forward on odd days and slightly aft on even days. If its a leap year, there will be no change.

Edge

How about laterally. I am pretty sure overthinking will cause a knife edge loop to snap out at the end.

wgeffon

My Feedback: (4)

That should be taken into account.

jrjohn

My Feedback: (24)

For what it's worth, I was just horsing around on the Thunder Power site. To my surprise they have Li-p0ly Reciever packs now. They have several packs, the one of interest is the 4000 mAh The weight is 158 grams, or 5.57 oz Thats roughly 1/2 ounce liter than an 4800 Fromeco Li-ion. The Li-ion is much much more durable. I would not trust those silly little Li-poly tabs on my plane unless I had a redundant system.

I had a battery pack fail on a big bird. I was using a single 3000 MaH "Super" Nimh battery. Cheap wire, bad soldering between the batteries, and unsupported wires as they exited the pack caused a loss of reciever power and subsequent crash. Cost me a grand in damages. Beforehand I could see the construction was not up to par and questioned the guy, he told me everybody in his club uses his packs and never had a failure. I was green enough to bite. The owner of the company made it all right in the end. He sent me Two 2200 Li-Ion battery packs with the same faulty construction. They are laying on the bench.

Watching the big bird fly away at full throttle was a little scary, you never know where it's going to end up, or who it will hit. Remember.... there is no failsafe to cut your throttle back when the reciever battery fails. Your on a ride to hell.

My point is, I don't test battery packs anymore. I go with whats proven. JMHO

BTW The battery was wraped to the max in foam.

john

going vert

My Feedback: (11)

I can't believe this thread is still going.

Boss - what is the issue w/ the Fromeco setup?

Bosshossv8

My Feedback: (10)

Some of you guys crack me up, LOL.


Maudib,

I greatly thank thee, for the enlightment of the max discharge rate. Using a 2400 mah for plane only on one othese monsters is pushing it. Pushing it to the point of no headroom, just like you said. changing back to 4800 is no biggie.

3.3 oz more won;t hurt anything I fly.

How I started using that setup was searching for weight loss on a bipe with smoke.

Wayne, I know what you are saying, and I agree. KISS. I was just going for as little battery as safely as I could.


JRJohn, sorry bout the bird going bye-bye. I go with what I trust, also. But trust comes from many factors. The weight issue can certainly make one look for creative and sometmes risky solutions.



The Li-po on ignition stays for sure.....maybe after a year of flying a li-po on the rcvr in a glow plane I will trust them for the RCVr.

Now back to the guy who just got his EF Yak, don;t use junk from your other planes to complete this one. Use the best you can afford.

And you can;t go wrong with the Fromeco 4800/2400 IMAc package. I was just trying to shave from it.

Now, I gotta go, my DR-109 and EF Yak 87" await in the car. Gotta get my daily dose.

Edge

Are you saying after all this rhetoric, you are going back to the same setup you had before. Boss, go to the bathroom more, if you hold crap in, it finds it way to your head, and you come with crappy ideas. Just a thought.

Maudib

My Feedback: (51)

It seems wise to always keep an open mind, share and receive experience and to occasionally be willing to allow yourself to change your mind.

In this instance I went to the trouble of building a "servo stresser" that used springs to apply pressure to a digital servos arm... 2-3 amps were seen on a single 5955TG.

I also hooked up a 5 digital servo plane with a whatmeter and tested receiver voltage/current with multiple servos at idle, flapping and with some pressure applied to multiple surfaces.

Based on that info I decided that a 2 cell 2400 was "marginal". Meaning would probably work fine... but for my own confidence felt the extra 3 oz was worth the "margin" and extended flying time.

It's subjective... sure. But then we all have our ways of developing confidence.

T Erickson

TBM claims 6A constant, 9A burst for their 2400 lions. If so, I doubt my receiver buss would hold up to much more anyways...... Always a lot of choices out there, just go fly sounds like the best advice a guy could take. as always, appreciate all the input here. T.

Bosshossv8

My Feedback: (10)

Edge,

Lighten up, yeah, after hearing that the 2400 is marginal, i keep an open mind. I have 3 planes that I pared down from 4800 to 2400 to save weight, after experiment with one.

But , what Maudib makes a point of , is valid. It will and has worked, but there is no headroom for that rare spike or servo lockup. Thanks, David.

I have plenty o' 4800's laying around.......I am sticking with the Li-po on igniton. Little alum tabs be damned....(or my airplane.) .

Hey, the original setup is bulletproof, like kevlar, I was just shaving, man.

Didn't you ever cut yourself shaving???

jrjohn

My Feedback: (24)

Boss, if you wanna save an ounce, go to the TBM site and buy a set of them new fancy titanium axles. 21 bucks, no worries. I'll have a set on this winters project. Has anybody tried them?

John

Bosshossv8

My Feedback: (10)

I wasn't really "trying" to save an ounce on this bird. It just happened when I was experimenting with losing some weight on a Bipe , to make up for the smoke system weight. When it worked...........2400mah Relion/ Thunder Pwer 1320.....I stuck it on all my 50cc bird's....happy as a clam that I was losing another 5 ounces.




This bird does not need to go on a diet, in fact there are times I wish I could have a 1 pound or 1 1/2 pound quick disconnect weight pack that I could add for windy days. Really.

The solution might be a smoke system , then add the 10oz of weight that 16oz of smoke weighs and not use it. On windy days 15-20mph in Chicago , I use a little spoiler to get her on the ground.

I would use the Titanium axles on my bigger birds. Had 1 axle fail this year, an OLD Du-Bro. But it was a high grass run off landing.

I did see a POS Aeroworks QB Yak break an axle on a normal landing, and after inspection all you could do was laugh. Well, the owner didn;t laugh. The axle was cheaper than what you would get from a Hobbico trainer. Abject garbage. In fact we USED a Hobbico axle from a trainer in the garbage can, to fix it. Nice hardware some of these kits are sent with.

THankfully EF hardware (American Made Du-bro) is trustworthy.

I will check out the TItanium axles from TBM, I got a 35lb'er that could use them. Thanks JRJohn.

Edge

Chitter Chatter blah blah blah. Boss, there is absolutley zero co-herent statements in you previous post. AW a pos? If you had one your rambling thought might make sense, but hard landings break stuff, you should know more than anyone. Darn it, now you got me rambling and not making sense. Think before post, re-think before you hit the submit button, then hit cancel instead, and all will be good.

Yes, I did shave once, but my dad took the blades out.