edh13

My Feedback: (9)

Yea they can pop and flash if charged incorrectly. But it's funny how people obsess about their batteries when in my (and most peoples) garage right now there is about 50 gallons of gas distributed among three cars, some filled propane tanks, couple gallons of nitro fuel, many cans of paints and solvents under presure, butane torch, oil, matches and a live natural gas line plumbed into the water heater with a fire burning under it. When I see the hobby shops and warehouses accross the world, with their millions of lipos stored, start going up in flames I'll worry about it. A couple of scary tales and a youtube video or two compared to the gazillion lipo's safely in use in electronics and hobbies doesn't even register on my give-a-crap-meter.

I believe it's our chinese chargers and / or lack of attention that cause our issues. Not the batteries.

Bozarth

My Feedback: (15)

I have taken several 4, 5 and 6 cell 4200 mah lipos and beat the pulp out of them in a fire pit. One finally went off like a weak road side flare. The others smoldered but never flamed up, including one that was shot with several .22 rounds. Here is a picture of one of those that smoldered after receiving the beating from a piece of rebar. After all of our "scientific" tests, it sounds like the best way to catch one on fire is to charge it incorrectly.

Kurt

pkoury

My Feedback: (7)

I have been going through some of my old model magazines and I got a kick out of the Safety Column reporting battery fires. The article would relate how the new battery being used in models were cathcing on fire. Funny thing is........they were talking about NiCad batteries. (I said these were old magazines). I have been modeling for a long time, I remember having to special order the dry cell transmitter battery from the drug store and using AA dry cells in the reciever. From dry cells, to Nicad. to NiMh, to gell cells, to Lipo, to Li-Ion, to LiFe I have used them all. What I have found the best for me is LiFe. I buy packs made from A123 cells. At first I was special ordering them with balance taps to be able to check the packs every now and then. I would charge the packs through the switch harness just like NiCad and use the balance tap to check the packs every couple of months. I have never found a pack that was out of balance. I have even found that leaving the switch on and draining the LiFe packs to zero did not ruin the pack. A friend left switch on, his charger would not charge due to low voltage but I was able to bring them back up with my Orbit charger. I have been flying this pack in a trainer I keep on hand as a test bed for a year now and the pack is good as new. I still have Nicad packs for some of the electronic ignitions and I use either my Orbit chargers or my FMA cellpro. I fly mostly scale models; the ones with digital servos or a large number of servos might have deans plugs (the real ones not the Chinese rip offs) but most just use standard Futaba connectors with heavy duty wire. I buy all the materials to make my own from Radical RC; www.radicalrc.com and I have settled on the heavy duty switches with built in charge jacks from EMS.

Summary- Lithium Phosphate A123 2 cell packs, no regulator, heavy duty wire harness, FMA Cellpor charger, batteries charged in the airplane.

GerKonig

You are right Kurt, do not forget to mention the hundred of millions of lipos in use people's cell phones or laptops. Why do those not have problems? Because they use the right charger and you cannot mess up:-) One thing I learned the hard way is that you ALWAYS have to disconnect the lipo physically from the controller after the flight (the controller otherwise will drain them until they are empty and the battery will "puff" or swell a little (the wrapper swells, not the battery). Nothing happens, no fireworks, but they swell and do not take any more charge (dead as a stick). do not ask how I learned...

In my 5 years as lipo user I never have seen high temperatures or smoke or fire. Nevertheless, I store them in an ammo box... I use cheap chinese batteries. My first lipo for a Telemaster was from Hobby-lobby. Expensive like hell, lasted 3 years. The cheap batteries from Hobby King lasted the same. I am now in the 2nd year of my cheap lipos w/o problems to report...

Oh, and do not store them for very long periods fully charged either... (like after your last flight in winter). I was told it is not good by people that know their stuff.

Good luck.


Gerry

acdii

Storage is 3.8 volts. A good charger should include a storage voltage setting that will either charge to, or discharge to that voltage. When you receive a new battery from a shop it should be right at or near 3.8 volts. This is where you want it to be if you are storing it for any length of time. Oh that is 3.8 volts per cell.

K-Bob

My Feedback: (1)

They still make NiCads?

planecajun

My Feedback: (21)

this is how simple it is my friend......no ivy league degree, no planes on fire...........no house burnt down..


JR FAILSAFE RECEIVER........A-123 6.6 VOLT BATTERY.......CHARGER SOLD BY COMPANY THAT MAKES THE A-123 BATTERIES.

DEANS CONNECTORS ON EVERYTHING IN THE PLANE. AND STANDARD UNIVERSAL PLUG TO PLUG INTO THE SWITCH.


CHARGE THEM IN THE PLANE, IN THE GARAGE, IN THE BED WHILE YOU SLEEP. CRASH THEM, BEAT THEM, DROP THEM IN THE

SWIMMING POOL, BURN THEM WITH A CUTTING TORCH. IT DOES NOT MATTER WHAT YOU DO. THEY ARE RELIABLE AND NOT

SO UNFORGIVING. OF COURSE, YOURE BETTER WITH LIPO'S ON ELECTRICS SO, JUST FLY GIANT SCALE GAS....[sm=biggrin.gif]

Bozarth

My Feedback: (15)

I think we need to separate the apples from the oranges. Apples = RX batteries. Oranges = Batteries to spin the motor. HUGE difference!

Kurt

Arrow IV

Dan, thanks for the info and I know lots of guys run the Lipos with brilliant success. The "Hysteria" BTW is in reference to me, not the batteries, ie "my hysteria". Technically can an inanimate object experience hysteria? I guess that’s for a different post… Just jokes! Here’s my deal, the nimh in my opinion are just like a chubby girl, just about perfect but not quite there… Someone said earlier “…enjoy the technology…”, and I totally agree, a leg up with the latest and greatest is usually the cat’s meow! However, trading one PITA for another doesn’t calculate on my slide rule. Here’s a real life scenario: I take my beloved nimh’s for a spin and unfortunately have to charge them every other flight, there’s my PITA for that set up. What I have to trade to get to fly all day is this: pop the top on the extra, take out the lipos, charge them in a bag or on a non-flammable surface, make sure they are cooled off, put them back in, screw the top back on and let er rip. I’ll bet dollars to pesos, there’s less time spent playing the nimh game. I’m looking for a more conducive and convenient check list, not a more extensive one. If I were flying different equipment, the trade off would be well worth it, but a 12 bhp gasser couldn't care less how many batteries are along for the ride. Maybe I’m off my nut, but I want my cake and eat it too! I want the performance of the lipo with the safety and ruggedness of the nimh. What cha think about the LiFePO4’s? They sound like they may be heading in my direction, any thoughts?

Valve floater

I have been using lipo`s for years. I don`t worry about voltage at storage. Mostly fully charged.I top them off to make sure they are ready. I had some in storage for 3 years fully charged (TP) and still worked great. I use Zippy`s and value hobby now and never had an issue. Keep`em in Ammo boxes anyway.

Sport_Pilot

One of many reasons I don't fly electric.

vasek

My Feedback: (4)

Now that's helpful

Arrow IV

That’s what I love about this sport, there’s a little somptin somptin for everyone! I actually share that “I’ll pass on the electrics” opinion somewhat (as if you couldn’t guess…) and most of it has to do with the concern about the volatility of the lipos. Again, lots of use with a perfect safety record, but at our club we’ve had 3 incidence over the last 3-4 years with lipos going rogue and those are only the ones I know about. Someone said earlier gasoline is just as dangerous, and it is, but how many billions of people use gas every day without an issue? More importantly, how many of those billions who use gas couldn’t hang with the Banjo Boy from Deliverance mentally???.... I don’t see gasoline making headlines on a nightly basis, I’m just saying. I’m not condemning lipos by any means, just wanted to hear what y’all had to say. Personally, I’m waiting for the next evolution, and by my tally the closest thing to lipo performance with nimh safety is the LiFePO4’s.

planecajun

My Feedback: (21)

The LifePO$'s youre talking about are actually the same as the ones i was talking about (A-123) Yes, if youre flying a gasser as you say, i couldnt have enough good things to say about these batteries. They would only be better if they charged themselves!!!!

Radical Departure

My Feedback: (13)

Been using Lipo for a number of years now. The only price of admission is spending a bit of time thinking through a setup. Pick the motor needed for the plane, then an ESC and batteries that are compatible to the motor. Only battery I've ever had puff up was one that was involved in a crash. I have lipos that are into their 3-4th year and still going strong. My experience has been this;

1. Buy quality batteries. I've owned mostly Evo, ThunderPower and Turnigy. Turnigy Zippy is quite a bit cheaper and I've been getting good performance from them.

2. Make sure the charger is up to the task.. in that it'll charge a wide range of types, cell counts and charge rates. i.e... if you're charging a 5cell at 0.5C, you'll be there a while. Then operate the charger to specs of the battery. It can be easy to want to get back out there in the pit and try to pump juice into the battery faster than it can take it. Myself, I prefer ThunderPower chargers. Pricey yes, but I can charge and balance 2 5cell pks at 3C, get excellent battery info. as well as storage modes, etc..

3. For connections I prefer Anderson Power Poles and use them on every electrical connection. Never had a connection fail and its rare I have to dig the solder gun out, as it is a crimp-on product.

As others have mentioned, I too use a 2 battery setup. You can start down the road of BECs and UBECs, which is fine for smaller foamies and so forth, but once you get into larger birds, dual set is the only way to go. In my current bird, a Porter PC-6, I run 2 5C 4000m batteries to power a Hacker 60-14L thru a Hacker Opto80 ESC. Its not tied to a switch. For everything else, I run a Fromeco 5200 Li-Ion which is tied to a switch.

And finally let me say that I'm not some electrical egghead. Watts, amps, milliamps and all the rest of it... hell.. I don't know half of whats being talked about. I'm a load-the-plane-grab-the-gas can-and-toolbox flier. But.. a couple hours of homework and some simple adding and subtracting is all thats needed. Like most all things, Lipos are typically going to give you what you give them. Well maintained and stored, you can get years of flying out of them and the odds of you having one blow or such are really quite small when considering the numbers sold and flying...
HM

jhatton

I would bet less than use lipos on a daily basis without an issue... go to any 3rd world country and you will find many more cell phones than cars... and each one will have a lipo, I am willing to bet they will greatly outnumber the number of gas users that do not use a cell phone...

The batteries are as safe as anything that stores power, it is if they are misused that can lead to problems

meyerwrench

I am looking for information for the correct charging rate for lipo batteries. i have 1s 3.7v 25c 200mAh, 1s 3.7v 12c 500mAh and 3 cell 30-40c discharge 2200mAh.    The first two are eflight batteries that came with my 120 SR and mcpx. I guess the 1s = 1 cell? What is the 25c and 12c? discharge rate?  Maybe in milli amps? The last battery is a Turnigy. 30-40 discharge is in amps? What would be the best charging rate? How do you figure charging rate?

cheezer1222

My Feedback: (3)

Not quite correct. Most, if not all, cell phones use lithium ion batteries. Not quite the same as Lipo. I still agree with your last sentence though.

Arrow IV

I totally agree with “you get out what you put in” and in most circumstances the people who either don’t know what they are doing or are a little less than Rhode Scholars typically make the most headlines, if nothing else we love our drama!... Also, if lipos were the devil in a little shiny wrapper, some kind of control would be placed on them I’m pretty sure. I’m not sure however the cell phone / lap top lipo comparison is on the level. Those batts are pretty much in a controlled environment, same exact rate of charge and same exact rate of discharge every time, the same is not true for the RC species. Just about anything in a controlled environment is safe (spare me the Chernobyl and Titanic references please…) Hydrogen, nitroglycerin, heck, even fat chicks aren’t dangerous in certain circumstances… Well as long as you don’t get caught… That brings me to my next point, this goes out to all the guys that like and use the lipos regularly, IF there were a battery out there that offered the same weight and power as the lipo, BUT safe as a Duracell, would you switch? Would you even junk your current gear and switch???

jhatton

Most phones use Lipo batteries now... only a few of the older larger phones use lithium ion batteries... I work at an electronics recycler and do not think we have seen a phone with a lithium ion battery come in in a few years....

acdii

The 1S is a Single cell battery. The C rating is its capacitance, IOW the amount of juice it can give out under load. The higher the C the longer it will last under load. < that is the underlaymens way of putting it. The flip side of that is the higher the C the more you can put back into it during a charge.

the 3.7v 12C @ 500 mah, charge it back at 0.5A, the 25C @ 200mah, charge at roughly 0.25A.

The 3S 40C can be chargted at an even higher rate, Idont know the percentage per C, but for my 3300 MAH 3S Icharge them at 3.5A, they are 25C. The higher the C rating the higher the charge rate can be without damage.

The higher the Mah the longer the battery will hold the voltage at a given rate. So between the mah and C the higher they are the longer it will last. You can have two 500mah batteries, both running the same hardware, but the higher C one will last longer. The math and explanation is a lot more complex than that, but should suffice in knowing what it means.

geeter

My Feedback: (110)

hey, you can always go back to nitro...........thats what i did........RON I SAW ROBERT HEIGHT AT 800 FT...........JOHN FORCE....

FallDownGoBoom

My Feedback: (1)

Meyerwrench:

Yes, 1s = 1 cell. Your first two batteries are single cell 3.7V batteries, and the Turnigy is a 3cell 11.1V (3x3.7V/cell).

"C" ratings relate to a battery's discharge rate. Your 25C 200mah battery has a theoretical discharge rate of 25 x 200ma = 5000ma, or 5Amps. Your other single cell battery could discharge at 6 amps, and the Turnigy between 66 and 88 amps. As they say, your mileage may vary, meaning that depending on cell condition, temperature, and lots of other variables, you may not see actual discharge rates that high. The battery capacity ratings are the amount of current the battery can delivery in an hour: your 200ma battery can deliver at total of 200ma in one hour, or 400ma in 30 minutes, etc. If you discharged it a theoretical 5amp capacity, it would last about 2.4 minutes.

Smart LiPo chargers usually charge LiPo's at 1C, or the pack rating in amps. So you could charge the first battery at 0.2amps, the second at .5amps, and the Turnigy at 2.2 amps, and all of them would take about an hour to charge to full capacity. If you charge at lower amperage rates than these, there are probably no problems, it just takes more time to charge the battery. If you charge at higher rates, you run the risk of overheating the battery, with all of the bad side effects (puffing, burning, etc.) mentioned above.

acdii

My DroidX uses a Lion, but there are aftermarkets that are Lipo. All 3 LG phones we have are also Lion packs. All my laptops are Lion packs. The only Lipo ones Ihave are the iPhone and iPad. The Cisco Wireless 7921 and 25 phones are also Lion packs.

Basically if the phone has a built in voltage regulator for charge/dischage and can keep a Lipo from dropping below 3.4 volts and charge it to no more than 4.2 volts, then the Lipo will work. If not then it can only support Lion.

GerKonig

There are 2 kind of lipo users as discussed) the ones that use them in the Rx and Tx, and those like I that use them to power airplanes (1/4 scale or giants in my case). I can tell you many of us dumped slimers many, many years ago. I only have gas and electrics. I am willing to chang to anything that proves to be a) better than what I have or b) cheaper than what I use.

Would I "junk and switch", no, I am not out of my mind, nor do I work in the accounting department of Halliburton:-) I would upgrade to the new technology when the moment comes, or when I see a real big benefit. (Like when I dropped the 2 stroke oily power plants). If you use something for 5 years with out problems, and like in my case do not know (sersonally) someone that had problems with the lipos, you have to have a reason to switch, in other words you would not switch because someone does not understand how to charge or use lipos. Sorry:-)

Gerry