SinCityJets

Use A123's.

SpiderJets

Charge and store your LiPos in a terracotta pot, not in metal containers (too risky ! ).

I have converted almost completely to A123 batteries after I had to dump about 15 Lipo packs in one weekend. They're fun but their lifespan is too short (and they're dangerous).
I'm very impressed with A123, they are extremely fast charging, by no means critical, deliver an incredibly high constant power, less expensive,...
They are only a bit bulkier&heavier and a bit less Volt/cell, but the rest is pro A123.
I even use them now to run my Kolibri turbines (in 2S configuration > same single pack for RX and ECU !), receivers, and JetCats.... next to the applications in small electric models of course.
No more NiCad, NiMh, Lipo, LiMnO,... I prefer A123 !


Nicolas.

powerjets

My Feedback: (1)

So Lipo is also dangerous when not being charged ???

SpiderJets

Murphy's law is powered by Lipo


No, seriously, they are not really impact resistant... Do a search on Google and YouTube...

powerjets

My Feedback: (1)

Is there any real -fire- danger when they are just sitting on the shelf in my workshop ?
cause my workshop is UNDER my house !!
Anybody ?

SpiderJets

There's always a risk... suppose they are a little damaged at the inside and the seal breaks inside a cell...

You can compare the idea of the risk at rest with an inflated air balloon with a weak spot on the surface somewhere. Will it hold the air pressure ? Yes. Is there a risk it will burst, even if it held for a while ? Yes.
Our cells are not used in a hard shell casing, hence always more submitted to handling/impact risk.

Boomerang1

Sorry for your buddy Mark, hope he is still going to Wang. See you there.

It has me amazed why anyone uses lipos in a turbine jet anyway. Different batteries, different applications. Sure, lipos have revolutionised electric powered models with their high energy density but is it needed in any other type of model?

Have they just become 'fashionable'? Most jets are flying bricks anyway so a couple of extra ounces for batteries is not an issue.

My thoughts too. I have just bought a couple of Eneloop packs & try those. The advantages of ni mi cells without the self discharge problems. Perhaps the best compromise for me. - John.

Paul Buckrell

My Feedback: (2)

Sorry to learn of the loss. The Avonds F-15 is a great plane and my experience is only with the old version! Been using Duralite Li-ion packs with safecharge and the Duralite charger and voltage checker since July 2004 because they have a warranty. Of the seven packs I own one has failed because of a deep discharge below 5.5V. Otherwise no problems. I charge these in the planes but like others would never charge a LiPo in plane. Even the 14MZ battery goes in a fireproof bag for charging.

Kevin Greene

My Feedback: (85)

If you guys knew how some (most) of these (LiPoly) packs were made you would steer clear of them...Only a thin "Mylar" type film separates the "plates" and without a hard outer cover of some sort to protect the pack, these packs are very susceptible to being damaged...

And yes...Just sitting on the shelf, or in your model, these packs can self destruct without warning...You never know if the pack was jostled just enough to put it on a course of self destruction....


Kevin

DelGatoGrande

My Feedback: (23)

yes i agree 100%
i confirm Lipos are way dangerus for use!

please ship them all to me!

Tom Antlfinger

My Feedback: (24)

Nico's comments about the Terracota planter is great. Gonna get one today.

BV, Tam, and now Shulman Aviation and other purveyors of hair dryer technology are not going to be happy about all this bad LiPo press. Forget about little RX and ECU Lipo packs. Those 40C-5S2P-6500maH packs, big as 2 salami sandwiches stuck together, are weapons grade when it come to an inferno if one of them lights off during a recharge gone wrong or rupture after a crash. Used with caution though, they have proven quite reliable and safe so far, but even a 1/1000 chance of a LiPo fire during re-charge could be disastrous inside your house, trailer, or car.

So.....Bottom Line from my experience which includes 1 fire from a post-crash rupture of a Li-Ion and unexplained overcharge on a Duralite Li-Mn which expanded to 2X normal size, but did not burn or rupture, using a dedicated Lithium charger, which has tested totally normal since the incident

Never charge unattended, preferable never inside the house

Never bury your Lipos in your plane where you can't rapidly get them out if you elect to charge them inside the plane

Never use tie wraps to tightly fasten Li-Po's....use Velcro and HD Double sticky tapes per Kevin Greene's comments. The separators and outside case are fragile.

Always check and double check your charge algorithm before pushing the start button on the charger. Nothing will destroy and probably light off a Li pack faster than a NiCd or NiMh algorithm. Preferably use one of the dedicated Lithium-Only Chargers on the market.

And Never Crash you Planes...

And almost forgot.....Switch to A123 whenever possible.

David Gladwin

...................but Tom, can anything be as good as these A123s. They seem too perfect, there MUST be a problem ! (using them extensively now, for both ECUs and Rxs. !!)

Regards, David Gladwin.

Tom Antlfinger

My Feedback: (24)

Hi David:

The only problem I have had retrofitting has been the modest increase in size of A123 over Li-Ions. In some of my tight installs with custom cut battery holders, they just don't fit, and I am too lazy to re-do the layout. I think that is holding back the Sparky's from jumping in as well. When you make up the equivalent of a LiPo 5S-2P 6500 in A123, it won't fit in the first generation of Hi Power EDF's out there at the current time.

Tom.

BaldEagel

Never leave your house with your car still in the garage, they have been known to spontainously combust.

Come on guys LiPo's are not that dangerous its the abuse that they get that makes them unstable and a bad charging regime.

Jet Cat cannot convert any ECU's prior to Serial No 2350 to use A123's and if you have kero start you have a problem, Nimh can not supply enough power for the ceramic plug without going to silly size's.

Anyone used a JetCat ECU with A123's without having it converted?

Mike

David Gladwin

No problem at all, just use a boost battery for starting. I connect a Duralite LiMn battery in parallel during start of my P70
kero. , disconnect when start complete, go fly !

Use of A123s on unmodded Jetcat Ecus MAY cause failure , of my two 160 ECUs , one was OK the other failed. soon fixed by JC. Both are now modified and work perfectly on 123s

and Tom size must be the only problem, slightly increased weight even allowed me to remove some lead from the nose of my Hawks. Can't belive how fast they recharge too, using the CellPro from SinCity jets. THE battery for RC use.

Regards,

David .

BaldEagel

Due to flight restrictions at my club field, I have to start on the patch, I am already carrying an extinquisher, a Tx, fuel overflow and you are asking me to carry somthing else as well, no chance.

I will ask again, has anyone used A123's without converting an early ECU?

Mike

mr_matt

My Feedback: (10)

Hi Mike,

There have been many people that have run 3 cell A123 with JetCat ECUs without problem, but it is too marginal. Many have had failures.

In any case, JetCat USA can do the mod on any ECU, the charge is US$25.

Hope that helps,

Silver182

My Feedback: (2)

Matt.. you have got to explain why (3) 3.6 volt cells would be supplying marginal voltage / current for the ECU? From what I have heard (don't know from direct experience) the A123 battery cell is the best battery available at this time. Please comment.. and ask Bob he must have some direct knowledge about the batteries also.
Lee

KC36330

i recently had my P-70 ECU updated to smart chip and asked Bob about the a123 mod and he advised against it.

flyinfool1

My Feedback: (2)

What Mike said.
Almost every cell phone, PDA, laptop computer and other small electronic gizmos that you use and charge everyday in your house and or car have LiPo batteries.
Do you really think that the lawyers would let that happen if they were all that dangerous.
When used correctly they are quite safe.

I have not seen many installations where the are used correctly.

Gordon Mc

My Feedback: (11)

He didn't say they supply marginal voltage / current - he said the use of A123's without the mod is marginal. I believe he means that the number of faliures that occur without the mod is sufficiently high that the risk/gain ratio is not clearly in your favor.

IIRC, the issue is that a freshly charged A123 can be too high voltage and damage the ECU.

Gordon

mr_matt

My Feedback: (10)

Bingo

c/f

My Feedback: (1)

Actually I'm quite surprised of the contained meltdown of this incedent and find it an improvement of LiPo technology of years past. Just 4 years ago the photos show a complete portion of house, garage, gone. I've been around a few Lipo meltdowns and to date have never seen the intense fireball of flames so popular with the LiPoSack promo vids.

I have been using LiPo since their being mainstream and find them to be the biggest source of Urban Legends than any other Rc item.

There are videos on the web that show an #11 exacto peircing one without incedent, I've witnessed a freind purposely drive a 1/16" music wire through one completely.
A freind drilled a 1/16" hole on his model and went a tad to much and into a new TP Lipo which DID NOT explode in his face but rather started a super generating heat swell in which he promptly removed and threw it into an open area.


While it is true TP packs are premium and hold voltages per cell closer, there are other items they dont accel in, Fact is I run Rhino cells and can discharge them to over 160 deg and they will not swell, A ThunderPower will swell around 140 deg. I was exxlusive TP 3 years ago but now exlcusive Rhino. I do charge all my Lipo's with an active balance charger adapter from Graupner to my Shulze MCduo latest software.

Charging in a model is absolute no no RULE #1, All incedents of fire IMO, a charger is invovled and ASTRO or MRC are most involved variety.


IMHO LiPo, "DO NOT" spontaneously combust, One item proven a contributor of this phenom is that DEANS mini polarized style plugs when left dangling in a model or batteries in a mass storage enviroment, CAN actually short circuit themselves and dead short a battery as the male pin can insert itself across the female and male pins of a close proximty plug of the mini polarized, I always put 5/16" vinyl caps on my mini deans ends. This phenom happened when a LiPo was left in a model for the ride home and the mating mini of the close proximity of the ESC made it short circuit. I never leave them in the model after use as well. And I cringe when I see the guy open up a case, box, container of all his LiPos with those dreaded minis in close proximity to each other..02

jeanfi

Hello,

Just to say that in our "indoor flying" local club, people use hundreds of LIPO battery..
I have never seen one of them explode of burn etc in 3 years !!!!

What you have to do is charging at 0,5C with a good balancer.

But yes there is always a risk....risk is everywhere...




JeanFi

Mace

My Feedback: (21)

I'll preface this with "if you haven't crashed you haven't flown." I have flown a lipo powered jet straight into the ground and accordioned the battery into mush without incident. I repeated this same procedure with a slow flying model and actually split the casing in several places on a zippy rhino pack with no heat, swelling or fire. I have another pack that when bought new reeked of lipoly chemical smell like it was venting. So although these are all extreme examples, it just depends on how you tear up a pack and if there is a good short, caused by wiring or a damaged cell etc. It would not be a good idea to charge a pack that is not balanced unless one knew the cell voltage and capacity for a particular pack. That is asking for trouble, no matter the chemistry. I can remember when a lot of folks were complaining of NIMH fires as well due to the fact that they were charging them at higher than C rates. They couldn't figure out that charging a pack to the point of overheating was not a good idea...

MACE