Hossfly

New MA; Dave Brown has some good info for you battery power folks:

http://www.modelaircraft.org/mag/APRIL07/president.htm

abel_pranger

Hoss-

No disagreement with his central point, but seriously now, anybody using LiPos that needed to hear this from DB at this late date must be living in a cave somewhere. If they have managed to remain ignorant of the SOP precautions for this long, they either can't read or have some serious comprehension issues.

Abel

YNOT

As always, AMA and DB 3 years behind the times.

abel_pranger

I don't think it fair to say AMA is behind the times on this issue, Tony. At least two regular contributors to MA (Bob Aberle and Red Scholefield) are clearly up to speed on care and feeding of lithium batteries. If there is a need to remind people not to let their guard drop when it comes to safe handling of batteries, and I'm not saying there isn't, it should come from one of those guys or somebody else with comparable recognition as a credible source on the topic. DB's qualifications? "I have gotten involved in electric helicopter flying........."

What sticks in my craw is that "The Board" in control of my favorite flying site takes the sophomoric ramblings from AMA's Grand Poobah as the Word of God. I suppose the next goofy rule re LiPos will be that only packs charged on balancing chargers are allowed because DB said "A large number of the fires that have been reported to me involve chargers that do not have any active balancing component." I have read the compilation of LiPo failure reports [link=http://www.rcgroups.com/forums/showthread.php?t=209187]Here[/link] since it started over 3 years ago, and don't see the correlation that DB claims. I wonder how the "large number of the fires that have been reported to (DB)" managed to be a non-intersecting set apart from the data set of such reports that Jim McPherson has collected. I smell a natural soil amendment from a bovine source.

Abel

Silent-AV8R

We had an incident at our heli site recently. A very experienced electric heli pilot lost a TREX600 to a mechanical failure (part failure, not maintenance related). The heli smurfed and the pack got slightly bent. He brought everything back to the pits and just tossed the pack on his work table. Another guy picked it up, and just basically twisted it a TINY amount. It went thermonuclear in his hand, he tossed it to the ground. It vented for several minutes (VERY exciting to see in person) then it caught fire. The pilot mentioned he had a similar pack (bent in a crash) sitting on his desk at home.

Another guy I know was charging his LiPo pack in his office, on the 23rd floor of his office building. He heard a "pop" sound, saw the pack puffed up, and grabbed it and headed for the elevator. Got all the way down, ran into the parking garage and to the top floor. Just as he got there, it vented.

Now I know the chorus will be that they are idiots, but they are not, and that's the point. And why it really is worth hearing the same old thing over and over again. Even if we are all so smart that it will never happen to us, sadly the rest of the hobby just isn't as intelligent as we are here.

abel_pranger

I won't join that chorus, and don't really mind hearing "the same old thing over and over again" where safety is concerned. I just want to hear it from somebody that knows what he is talking about, else it goes in one ear and out the other. DB has a job to do; he outlined 10 objectives for AMA soon after he took office (apparently the MBO concept sounded good to him at the time). One has been met: spend money on the Muncie flying site. He's got plenty left to do without stepping on the jobs that better qualified people are charged with doing.

Abel

Hossfly

Well I don't know POOP about Lithium Polymer batteries. I won't know anymore when I get laid to final rest as electric flight -- other than maybe something real simple withh NMH and a grandkid in the backyard --will never happen with me. Now DB used the term Lithium of "any kind". Well there is a lithium in my watch! [:-] Scary!!! I have been using Lithium Ion for a long time in my airborne packs and they seem as stable as Nicads, if treated half way decently.

If I really wanted batt. info. then Ol' Red or Bob Aberle would be the Men to ask. When they talk Bat. even I can shut me mouth and open me ears! Look out Able, the sky is rumbling and may fall, as we are on the same page again. Scary!!

However I have in the past couple years been witness to several Pattern Pilots lose several of those $800 power packagers at the flying field. Only one was still in a plane after a crash. H-ll, a plane is SUPPOSED to burn when it crashes. I only had one ever do that and it was a CL Combat with a Bladder tank with 40% nitro. PRETTY sight it was but nitro and methanol fire is difficult to see, just a tad of blue flame as things turn to toast. [>:]

JUGFLIER

I think this is an election year. Maybe ole DB is just trying to modernize AMA, starting with himself. lol

Red Scholefield

My Feedback: (9)

Trust me, from the letters I get, ignorance of handling batteries, yes even our venerable Ni-Cds, is rampant. Someone must be offering graduate level courses in stupidity somewhere.

littlecrankshaf

My Feedback: (58)

Real nice post Red.

Thanks to the brow beating and equation of ignorance to stupidity you can count on a very long line of recipients for Red’s diploma.

Hard to understand how you can label those seeking info from you as stupid, considering the value you have of yourself…go figure.

Glacier Girl

My Feedback: (4)

Ummmm, well as an electric flyer using lipos almost 100%, at least in my case I read everything I could get my hands on concerning these packs, before buying my first.

Ok maybe I'm different but I tend to handle them like a pissed off rattlesnake. But even with me following the "rules" I still had a pack let go. Luckily all I ended up with was a little soot on the garage ceiling. Ok and my witts in the next county from the experience.
But what I'm trying to get at is even if you take all the right precautions, things can still go wrong. Now, I think, and maybe I'm wrong, but what Red was getting at was that the newbies and maybe even some of the experienced fliers out there really have no clue as to the dangers of these packs, if mishandled. Some of the blame lays with the suppliers, which I understand business, don't cut your own throat by telling your customers it can be unsafe. But they should. Also those that do use and know the dangers should also help spread the word.
Not just the benifits of using them, but the downside also.
The explosion of the electric portion of our hobby has made this type of problem even worse, and I'm afraid that the current set of new fliers tend to come from the instant gratification end of the spectrum. Must have it now and damn the consequences. Which will even more so make lipo horror stories abound.
No I won't put DB down for doing this. The word needs put out there, and it needs put out more then once. New fliers start everyday. Yesterday's news isn't going to help them.

ptulmer

My Feedback: (5)

I can't believe I'm going to do this. But I'm going to agree with DB. This is a serious issue made more serious by the cheap import batteries that are made without any QC. As long as there are people out there who will take the risk for a few bucks, he has every reason to harp on the subject. I didn't read into that he was claiming to be an expert, just passing along info that he "collected". It may not have been well thought out, but it was well intended.
So, the next time you go buy batteries, ask yourself if you have the appropriate place and equipment to charge it and whether your house and possibly your life are worth the ten bucks or so difference in price!

BTW, did you know that there have been nine lithium battery fires on commercial airplanes since 2005? Lithium batteries are a huge leap forward in technology. It's just too bad that manufacturers are going overseas to buy them. It looks like you'll have to start removing your cell phone battery and placing electrical tape over the contacts just to get on the plane. That's what TSA is looking at.

Red Scholefield

My Feedback: (9)

ptulmer makes a lot of sense. What TSA is looking at however is scary. US Government agent with weapons carry credentials is allowed on airplane with his pistol - but only after he surrenders his nail clipper.

When you consider the number of Lithium batteries carried on airplanes over the past years, the chances of an incident are much lower than both the pilot and co-pilot having a heart attact at the same time. But they have a better union. :-)

What is next? Removing the lithium battery from your Casio watch? It will only take one bureaucrat wanting to make a name for himself to make it happen.

Know your battery, and how it operates. Knowledge is better than cast iron pots in keeping you safe.

ptulmer

My Feedback: (5)

Red, I thought nine in two years was high! Those would almost certainly be defective batteries. Even my Dell laptop had a recall on the battery due to the fact that some had already "exploded". The technology is sound, the implementation is, well, it's imported. Some 7 year old girl is making these thing for pennies a day. You get what you pay for in batteries.

BTW, the stories I could tell you about the Feds. Yikes.[X(] Never will put it in writing though. You'd have to buy me a beer or six.

gzkpez

That was a great column. Thanks Hoss for bringing it to my attention. There are new user of the lithium Poly batteries all the time. There are also alot of us who are moving in to much bigger electric powered planes, with several pounds of batteries. And the batteries are geting more capacity per oz/ all the time.

Do not confuse lithium ion batteries with Lithium Poly. Lipo's have the potental to cause much more trouble. Even Lithium ion battieries are being reengineered for better saftey by the large mfgs such as Panasonic and Sony. Their have been major recalls of Lithium Ion batteries by Dell, Sony, Apple, etc...

A flew years ago, I saw a high end Laptop at a meeting with what was discribed to me as a new type of extra capacity battery, trying to impresss me. It later exploded in their cafe that afternoon. It burned out the table. I was impressed.

I am not sure how to put out a fire like that other then smother, is water bad?

pcsketch

I've been flying nicad electrics since 93. I have avoided the 'lith' batteries knowing the fire danger. Now the AMA Prez has explained how to use them: store/charge in a fireproof container and charge with a 'ballancer'/charger.

I've removed my Saito .30 from my Sonic and now ready to brushless (yep, been flying 'brushed' for 14 years). Been waiting for a safe way to fly my glow size aircraft as electric. (not saying much but, a Easyfly .40 flies with an Astro 15 geared, so does a Taub .40)

aeajr

My Feedback: (2)

The points made in Dave Brown's article are the kind of points that need to be made over and over again. Good advice is always worth hearing and good procedures have to be practiced

I try to handle my Lipos carfully, charge on balancing charger and the like, but even I need to be reminded from time to time that this is important.

I avoided lipos up tp about a year ago, but now I fly almost all Lipos. The advantages are so great that you just can't igonre it. And if you have to follow different procedures, well than so bee it.

Hossfly

OK aeajr, you and red are the electrons of this thread but neither have made any points about the differences between Lithium Ion and Lith. Polymer. (sp.?) DB says Lithium of "any kind".

The Lith. Ion seems no trouble. I charge when I think I need to in the airplane just like a NiCad except using the LI supplied chargers. So far, for some years, no problems. Anyone care to comment on the Ions instead of simply the 'polywogs'. (Down here a pollywog is a small bait-stealing lowest class catfish that is pure garbage, which I think is called a bullhead up north. He can bite you and fin you which is very painful. I despise them and if I catch one, I try to help rid the world of them. [:@] )

aeajr

My Feedback: (2)

I have not used LIon cells but as I understand it, they have to be charged exactly the same way we charge Lipos. If you over charge them, or charge at a high rate, I believe there there is still a risk of venting, but it is less noticeable because of the hard shell. I am not certian of this, but this is my understanding.

LIon cells are definately less prone to damage dure to their hard shells. However that is also what makes them less desirable as battery packs for small electrics. That shell adds weight.

So, from a charging and storage point of view I do not believe there is much of a difference.

From a risk of physical damage, which can lead to venting issues, the LIon are safer.

Hope I have this right.

Red Scholefield

My Feedback: (9)

The main difference between Lithium Ion and Lithium Polymer is the durability of the cells. Lithium Ion being in a metal can are much less susceptible to physical damage which could cause shorting. Otherwise the same hazards exist. The cells in the laptop battery fiasco I understand were cylindrical Lithium Ion cells, not the Lithium Polymer. If you tear down a laptop battery you will find cells designated 18450 or something on that order. The one I just looked at (Gateway - Solo 5300 14.4 V 3600 mAh) had Sony cells, in 2P4S configuration. Two cells connected in parallel and then 4 of these in series. There were taps to a fairly complex circuit board from each node of the of the battery. Testing these cells in 2 cell parallel pairs indicates the pack was pretty sick from capacity delivery standpoint. Now I'm going to move them outside and see if anything happens from a constant current charge of 6-8 amps.

cyclops2

Red.

Are you going to bypass the supplied safety charging and discharging circuits ?

Hossfly

Thanks to you and Red. For me, batteries run the radio system. I need noise to pull the flying machine.

Been married far too long to trust anything that ain't making a bellowing noise at me!!!!!

Red Scholefield

My Feedback: (9)

No way, No reason to mess with them any longer. The best of the four 2 cell packs gave on the order of 1200 mAH. Not good when they should have been 3600. Discharge curves were sorry, drop to just above 3 volts in under 10 minuets at modest C/5 discharge rate. These cells are toast. Over 5 years old so it is no supprise.

Red S,