rrragmanliam

My Feedback: (1)

This was a responce of mine in the "Using LiPo's Safely" thread. The honchos booted it out. Said it didnt belong there, whatever. I guess theres to be no disenting opinion on LiPo's there!

Just look at all the technical informatin you have to post in order to "use LI Po batteries safely". Bottom line is there is NO way to use these batteries safely. Don't get me wrong, I understand that there are aplications where these batteries have advantages over NiCd and NiMh, but unless your flying superlight stuff indoors the risks outweigh any advantage gained. Even if all prudent charging precautions are adhered to, these packs can be violate and a severe fire hazard, not to mention the risk of personal injury if you or someone else happens to be around when one of these packs "blows". Other than the earlier indicated aplication( indoor superlight flight) you can save the same weight with building design, techniques, and the selection of other components ( servos, hardware radio components ect.) and spare your self the inherent danger involved in using Li po's. No offence intended, just one mans opinion.

Rrragman

Tiger

My Feedback: (7)

Gee, Hope you don't have a cell phone, or a laptop, or a PDA, or a digital camera?? Chances are, you are already living with Li-Ion technology alreay. It's all around you, all the time. Has been for a long time.

rrragmanliam

My Feedback: (1)

Well your right Tiger but a couple of pionts. In all the scenarios you listed you have to unerstand that all these devices have smart circuits. These circuits will:
A. Not allow the LiPo's to discharge beyond a certan voltage.
B. Monoter charging conditions (input volts, amp draw,state of charge, temp)
C. Not allow the LiPo to dicharge a too fast a rate.

I hear what your saying and I am by no means a technical Liddite. There are many applications where Li Po thchnology makes sence. Where it does, the safety is designed into the machine. This is not always the case in the RC world where many people use a technology simply because it's the latest and greatest. In many cases it's ok, but with LiPo if you don't know what you doing you will at the least spend a bunch of money replacing ruined packs, and at the most risk personal injury and property damage.

rrragman

tunnelvishon

It will only be a matter of time before all lipo's will have taps for individual cell charging and monitering. Having seperation between cells in construction would also help. Like most high tech stuff the product came out before the (safety)support was really ready. I too have only tested the water with lipo's (got 1) and am waiting until one comes out with a charger that I can leave in a safe place to charge while I sleep(soundly). My planes and gliders do fine on nicad and NMH and I feel that the weight reduction lipo's offer, really only benifits those planes that float away on you with a 3 mph gust of wind. 8C rating of cells is pretty well c**p too unless you want noisy trouble prone GB's thrown in on the top of it. I enjoy the few minutes it takes to change out a battery pack so the extra time in air means nothing to me. I figure in about a year or 2 we will probably have relatively "safe" lipo's and another year or so before they are reasonably priced. Used to be that people worried about their nicad batteries not cycling 500-700 times...now they worry about starting brush fires with crashed planes, cars and homes being burnt down.....ahhhh.....progress.

Shortman

My Feedback: (21)

The future is already here, just look for it

Tanic packs have all been tapped for individual cell balancing and checking (although as you may think, it is not needed at all)

Thunderpower is making 10C discharge batteries this spring that will be the future for many planes, mine included.

If you are talking about safe charge circuitry, and you say no one has it, umm read www.duralitebatteries.com

Duralite Plus has built in safe charge circuitry so that a pack cannot physically be overcharged or undercharged and ruin the pack. CANNOT, so there is your answer, you just didnt look hard enough.

Li Poly has more than 3 times the capacity of NiMh and Nicad, a Nicad or NiMh can lose as much as 20% of capacity when fully charged sitting in less than a week. Lithium Polymer will hold a full charge for 6 months, losing only 5-6%!!! How is that bad?

Lithium Polymer is environmentally safe and not required to take to a certain chemical clean up facility LIKE your suppose to do with Nicad or NiMh.

In truth, any battery can explode if overcharged and not charged properly, the Lithium Poly batteries just require you to charge correctly. I am 16 and can charge a lithium polymer, so its not rocket science. correct cell count, and 1 C charge and your done. I personally think its easier.

Nough said, Lithium Poly is here

arx_n_sparx

Any cells have the potential to start a fire in a crash. Most LiPo problems occur when charged improperly (too high a charge rate/voltage or imbalance). I have the parts on order right now for the Scott Henion charger http://www.shdesigns.org/lionchg.html and the balancer circuit offered by Suzanne http://www.rcgroups.com/forums/showt...hreadid=157641 All the parts are coming from Mouser
http://www.mouser.com/index.cfm?handler=home except for the MAX921CPA's which are coming from Futurlec
http://www.futurlec.com/cgi-bin/search/search.cgi . The battery pack must be center tapped (I'll do that myself). I know I'll sleep easy.......

Brad

P.S. I plan on charging inside of a box made from drywall - it's highly fire resistant.

arx_n_sparx

Any cells have the potential to start a fire in a crash. Most LiPo problems occur when charged improperly (too high a charge rate/voltage or imbalance). I have the parts on order right now for the Scott Henion charger http://www.shdesigns.org/lionchg.html and the balancer circuit offered by Suzanne http://www.rcgroups.com/forums/showt...hreadid=157641 All the parts are coming from Mouser
http://www.mouser.com/index.cfm?handler=home except for the MAX921CPA's which are coming from Futurlec
http://www.futurlec.com/cgi-bin/search/search.cgi . The battery pack must be center tapped (I'll do that myself). I know I'll sleep easy.......

Brad

P.S. I plan on charging inside of a box made from drywall - it's highly fire resistant.

tunnelvishon

I am well aware of all the manufacturers claims and advertising...however...I take them with a grain of salt (nothing new in the battery world). Take for example several postings on how brand new packs have arrived for customers out of balance in voltage. Many independant tests have shown that 8C-10C load ratings are exagerated for lipos and that to be safe not to exceed 6C. The word "explode" should be used with some caution too. Soda bottles "explode" when dropped but they don't burn your house down or ignite your clothing. I have lawn darted a few planes in my lifetime and have yet to have one blow up from a nicad or NMH battery. Of course the wiring and solder joints may fail and produce a short...but thats about it.
Explain to me how I run a 20-25 amp DD motor on a ?s1p lipo without puffing it?

tommy s

My Feedback: (55)

Funny how someone mentioned cell phones. There was an article in the Houston
paper a few days ago about a womans cell phone exploding.
I understand about people wanting the latest and greatest new whatever on the
market. I am not immune to this either, but I really can't see what the need for
Li-Po batteries is unless you have a very special need for them such as the pro
pilots do. I have flown in competitions for a lot of years, and still have pattern planes,
and have never needed anything beyond ni-cads.
I guess I still believe in the K.I.S.S. method of doing things and Li-Po's are anything
but simple.

tommy s

arx_n_sparx

Well, I guess there are risks involved with the advantages. Some are grabbing at LiPo's, and some aren't. Those who do, are basically guinea pigs for this emerging technology, and we all know what happens to guinea pigs in laboratory situations........ I don't blame those who take the wait and see approach, I would myself; however, I'm just getting back into the hobby after a 15 yr lay-off, so I have no batteries. I'm grabbing at the brass ring because batteries will cost me any way around, so I might as well get the "good" ones......

tunnelvishon: You won't get 25A out of any Xs1p Lipos unless you get huge cells - try Xs2p, or Xs3p. They'll still be lighter and have more Ah....

Brad

tunnelvishon

Its funny how switching from 1p to 2p on lipos is taken so lightly...in a simple solution you have introduced 2 new problems...twice the cost...and twice the weight. I guess there are shortcomings that need to be worked on or else we will have to wait and see if the new emerging lithium sulphate cells will deliver some power under 10C+ load as suggested. I am beginning to wonder if the present day lithium polymer cells will be Beta video tapes of the future simply because the chemistry limits its ability to handle high loads and a dead end has been reached.
On page 29 of march issue QuietFlyer they tested the 2200-mAh Tanic Li-poly cells. The surface of the cell was indented with ballpoint pen markings(date), balsa wood was used to seperate the wires and masking tape was used to protect connections. Hmmmm?

zero244

My Feedback: (1)

I dont see the facination with Lipo......I realize they hold a charge well......are compact and lite wieght. The of information on how to charge and maintain them is limited. The charging devices give limited info on a packs condition. They work fine in laptops, cellphone, cameras etc..........but these devices dont fly..........or crash.
Nicads and Nimh batteries get the job done......they are a bit heavier. But they are easy to charge and maintain. If you want to use Lipo.....do so at your own rish.......dont whine and wimper when your plane comes crashing down like a stork after a fish.

Stick with what works.............Nicad and Nimh.

Just my two cents.

Shortman

My Feedback: (21)

Li Poly is safer then most think, I crashed my Li Poly battery 2 times once from 30 feet up and it still works 100%. The capacity and voltage is even exactly like it was before. No balooning or that non sense. If you dont like it, dont use it, but your missing out.

MHawker

My Feedback: (16)

I just looked at my cell phone. It uses a Lithium Ion battery, not Lithium Polymer. Is one more "stable" than the other and is this why LiOn's are used in cell phones?

tommy s

My Feedback: (55)

I read one report that said if you crash your airplane you shouldn't even take
it home or put it in your vehicle for a number of hours because it could catch
fire and maybe explode just sitting there! Doesn't sound safe to me.

tommy s

RDespins

Ok I'll bite. There is nothing more magical about LiPos than any other battery out there. The only true difference is that they are more sensitive to a couple things, Overcharge, Overdrainage, cell imbalance and damage (which I have a hard time believing considering they test them with a nail poked through the cell).

LiPos arent wrapped in a hard metal case like NiCd or the like, Don't poke/beat on them. (hard to grasp I know).

Use the proper charger so you don't overcharge them. (owwwy my wallet hurts after spending 20-50$).

Don't run them down to less than 2.5-3V per cell.(Most guys are doing similar things with NiCds?).

Every once in a while, check the voltages of your cells. (I Spliced the wires between my cells so I can charge each cell to the same amount from time to time).

I think I'm going to faint with all the huge differences between these batteries. Just be a little more careful with these batteries than the "accepted norm" and the "Good Ole boys" can keep flying their AM radios in some farmers cow pie filled field. =) Progress is dealing with the shortcomings of new items until bigger and better rolls on in.

Tiger

My Feedback: (7)

The real difference between Li-Ion and Li-Polymer is the packaging. The chemistry is the same. The Polymers can handle a higher output cuurent because the flexible packaging (Polymer) they are in. If they swell a little, no issue, However, the Cylindical Li-Ion packaging is of course ridgid and would not except some swelling from over charging without rupturing, so PTC's are put in them to reduce current flow if it gets to high. The two type really were designed for different type of applications.

For the one that said, stick with waht works, well..... I guess you still drive a Ford Model T. They worked just fine as well.

Cheers!

rrragmanliam

My Feedback: (1)

Tiger, There's more proven "old " technology used in that plane you holding than new state of the art stuff. In many ways you and I are flying alot "model T" technology.

ml3456

Too many opinions here with not enough fact. If you don't like them or don't want to use a little thought to set up and use correctly, don't use them. But to blantantly say these are dangerous is wrong without stating the facts. There are a "couple" of threads about fires, and most admit it was OPERATOR ERROR, no neesarily the batteries.

Lets be factual here guys. Peopel will read this and think their phones are goint to blow up!!

ChuckAuger

My Feedback: (12)

People run highly explosive gasoline in airplanes all the time, yet chaos hasn't ensued. I'm sure somebody, someplace has blown his house up by parking a gasser near the pilot light on his water heater.

I like LiPo's. I'm confident in my ability to use them safely, and have had no issues.

And I don't park my gassers by the water heater.

Tiger

My Feedback: (7)

Only by having no other choices or lack of funds for more modern equipment.

Shortman

My Feedback: (21)

I hear the Lithium Ions with the cylinder shaped cells allow heat to vent better so they rarely would catch on fire. Basically, just more robust. Like they said above, 99% of the Li Poly fires are from improper charging and not being smart. Otherwise, they are as safe as any other battery out there.

Hangtime

My Feedback: (19)

Kudo's to those brave and intrepid souls that continue to explore the edge of the envelope.. my hat's off to you guys! Thanks to your determined journeys to the edge (and occasionaly beyond) of technology, the equipment and applications we all get to enjoy in R/C are better than ever before!

Those of you that don't want to hang out on the 'edge', and instead decide to approach your aircraft setups with a more 'proven and durable' (opinion) type of battery product in their (to them) precious airplane should feel free to do so without fear of reprisal from the more voiceiferous proponents of the current favorite 'latest, greatest battery technology'.

Vis-a-vis, those folks out there on the edge should be able to pursue their continued testing and refinements of the latest battery technology without having to defend their desire to take things to the next level. We ALL stand to gain by their efforts.. lets help 'em by paying attention and evaluating the data fairly!

Regardless of how us 'old fharts' view the new stuff, it's here, it's gonna stay here, and every day that goes by we can learn something that's of benefit to the hobby in one form or another.

Keep 'em flyin, gents! ... after all; that is what it's all about, right?

ChuckAuger

My Feedback: (12)

I'm not trying to impose reprisals on any damn body.

Rubber power was great. Gas spark was more powerful and more dangerous. Glow fuel is highly toxic yet less explosive. Gasoline is down right explosive.

Name yer poison, take yer pick.

People still fly rubber power, that's fine by me!

My particular plane was a wallowing turd with NiMh power. Lipos brought it to life! I would have quit electric power right then and there if NiMh was the pinnacle of electric power. Now I have a half dozen brushless power set ups and many Lipo packs. I fly them almost daily, charge them almost daily. Love them daily.

I'm not particularly in the market for any gum rubber at the moment, but if anybody is I'm not gonna stand in his way.

Same with batteries.

arx_n_sparx

I'm not sure if was said here, but....

I've heard the "argument" before that NiCd is "NASA/Aerospace" certified. What you have to realize is the fact that to become certifed, your product must be extensively tested to get the certification. Once you do get that certification, you can't change a thing!!!

Of course, this explains why the space shuttle flies on a 386!!!!! computer! It also explains why NASA still uses NiCd batteries, when they could use NiMh and get double the mAHr out of them (or Li-Ion and get more).

Yes, we "bold experimenters" will carve the trail for the rest of you Luddites, and you will follow in our footsteps at some point.

I just like the fact that my planes have a better P/W ratio, and can stay up much longer than using "tradional" batteries. Yes, there is a new learning curve to these new batteries, but if everyone shunned progress, then no progress would be made........

Just my .015 cents (.02 Canadian)

Brad