lipo misinformation

[ozzie-crawl]

i was talking to some guys yesterday that hadnt long gotten acouple of fe boats.
one of them raised the concern that if his lipos got wet it would blow his whole boat up.
i was told the same thing from a lhs when i first brought lipos for a boat.
story i was told.
guy driving down the road in his station wagon,electric helicopter in the back
a bottle of water tips over and spills water on lipos,the resulting explosion is that big it blows the rear hatch of the station wagon.
anyone else heard any crazy lipo stories

[m4a1usr]

i was talking to some guys yesterday that hadnt long gotten acouple of fe boats.
one of them raised the concern that if his lipos got wet it would blow his whole boat up.
i was told the same thing from a lhs when i first brought lipos for a boat.
story i was told.
guy driving down the road in his station wagon,electric helicopter in the back
a bottle of water tips over and spills water on lipos,the resulting explosion is that big it blows the rear hatch of the station wagon.
anyone else heard any crazy lipo stories

Well that story is an easy one to debunk. Stick a lipo pack in a bucket of water. If it explodes you know the stories are true. But I bet after hours of being dunked your going to find they are just wet and slightly drained. Water does not conduct well enough to "shorten" out a pack. Back when we ran brushed motors one of the burn in or seating the brushes methods was to immerse a motor in a cup of water. Salt water is more conductive but still not enough to short out a pack.

Over charging is the only credible story I have heard that causes a lipo pack to burn or become unstable.


John

[egneg]

I haven't seen anything personally but I did read all the horror stories about how they went up in flames if you looked at them funny.

[ozzie-crawl]

john wasn't saying it was something i believed,just a couple of stories i have heard people say.

[westbeach]

Time to call in MythBusters. I call this Busted! :rofl:

[m4a1usr]

Just remember one of the disposal methods for bad/ damaged/ at risk lipo packs is to what? Dunk it in a bucket of water, right?

Now packs going going high order is something that happens. Usually due to damage from a crash, deformation, shorting the connections, charging at abnormal rates, etc. Abuse.

But really getting a pack wet? That alone will not cause lipo packs to become time bombs or become unstable. Water alone is not the effecting factor. Got to be something else.

John

[Rex R]

not to suggest that high output batteries shouldn't be treated with respect, but I haven't heard of any 'mysterious' explosions after lipos got ejected into the pond I run at. I have seen/heard NiMH cells 'venting'(after being abused) though.

[properchopper]

Let's be fair to the clerks at our LHS - these poor folks are the ones who previously applied for work at the 99 cent store but failed the price-check test. :w00t:

[ozzie-crawl]

i think these stories started at lhs,most of them no nothing about lipo battries.
plus they have the old "i dont stock it so its voodoo magic" attitude.
just out of my own couriosity a few weeks ago i rang 4 local hobby shops,my question was simple do they stock any neu or castle/neu motors.
none of them had even heard of such things,one shop put me on to there resident electric expert,this is his answer "none of us have ever heard of such motors as we dont stock cheap chinese rubbish" :eek:

[Fluid]

Salt water is more conductive but still not enough to short out a pack.

Actually salt water is a fine electrical conductor, and it is for that reason that many LiPo pack makers recommend putting a discharged pack in a bucket of salt water (not fresh water) prior to disposal. The salt water makes a direct short between the + and - leads, draining the pack safely by controlling any heat generated.

LiPo cells are watertight, meaning no water can get into the chemicals unless the cells are cut. Water damage from wet cells is usually due to corrosion of the tabs and leads.


.

[m4a1usr]

The salt water makes a direct short between the + and - leads, draining the pack safely by controlling any heat generated.


.


Incorrect. Actually a salt solution is no where near a direct short. It takes days if not weeks to discharge any pack immersed into a salt bath. While a faster discharge will occur using a salt solution both will eventualy do the job. The electrical conductivity of a salt solution improves with the percentage of salt ions being suspended but it will never be a direct short. That would only occur with a conductor such as metal.

http://www.rctoys.com/pdf/thunder-power-disposal-of-old-damaged-lipo-batteries.pdf

John

[Simon.O.]

Dangerous lipos.......dangerous users more like.

Here is a copy of my post form another thread.

In all fairness to the "dangerous and explosive" lipo grenades that we like to power our models with I have tried a few things.

Over the last few months I have puffed a few cells and they are no longer considered safe for me (by me) to charge or use.
These are some of the tests that I did.

Run over by the tyre of my Hilux (Four-runner) and was squashed. It vented and that was it. Just a bit of gas
Repeatedly thrown across the concrete driveway. Nothing happened so I ran that over too.
Hit with a crow-bar pointy end first. A small flash and vent
A near full 4S pack that vented a cell in the boat due to water ingestion.
This one was left with a 100W lamp to dump the pack to zero. No puff or anything. That got run over too.
.

QUALIFIER
I will say now that all of these events occured under quite safe and controlled conditions.
I know what risk minimisation and hazard control is.
There is very little chance ( you can never say no way ) of me being hurt or any property being damaged.

DISCLAIMER
I did this so that I might know how "dangerous" lipo cells are.
I DO NOT advocate anyone trying this. If you do and get dead don't blame me.

Lipos are fine if handled with a bit of care and common sense.

Don't get me started on how dangerous petrol is.

btw you should have seen some of the destructive testing I have done to Nimh cells...........BOOOOOOM !!

[andym]

Run over by the tyre of my Hilux (Four-runner) and was squashed
Simon are you going to tell the truth now???? You and I both know you forgot to take the lipo out of the boat :doh:

[Simon.O.]

Simon are you going to tell the truth now???? You and I both know you forgot to take the lipo out of the boat :doh:

I have never run over one of my hulls while the battery was in it. :olleyes:

[785boats]

I've got one for Ya. And yes it was my fault.
My little 25" mono (Bulletproof) has an anti spark resistor soldered across the terminations of the safety loop inside the boat. (See the Pic.)
Even though I disconnected the safety loop one day, I forgot to disconnect the batteries inside the boat. The batteries were HiModel 2 x 2s 3600mah 25c in series.
After I got home late from a days sailing & unpacked the half a dozen boats & gear, I forgot about the batteries until 5 days later when I was going to start charging some packs for the weekend.
When I measured the voltage they were down to 0.69V per cell in one pack & 0.70V & 0.71V in the other pack.
Now most misinformation would say that they were stuffed & should be thrown away. But as they were discharged under such a light load & were in no way puffed I figured they were worth saving.
Now as the lipo charge cycle would not recognise the low voltage to start charging I placed them on the NiCd cycle at 0.5A. One pack at a time.
It took about 8 minutes to bring the voltage up to 3.3V.
I let them rest for about 30 minutes & the voltages had dropped to 2.19, 2.12, 2.55, 2.79. so I charged them again on NiCd up to 3.5 V, then plugged them into a balancer to balance them & left them for a day.
As they were still pretty closely balanced I then did a full balance charge on each pack.
Pack one cutout after 112 minutes at 4.11V/cell taking on 3960mah.
Pack two cutout after 118 minutes at 4.14V/cell taking on 3876mah.
I then topped them up to 4.18V/cell with an extra 200 or so mah.
Their first run in the boat I stopped at 3.81V/cell (resting voltage) and they both took on 2182mah & 2188mah respectively, topping off at 4.18V / cell.
And they are still running fine after half a dozen more runs.
No heat or puffing problems & just as much kick as they always had.

[SJFE]

Andy... Little to much boob action in the picture Sir. I enjoy slammin jugs as much as the next guy:thumbup1: keep in mind it's a family forum bud.
Tommy G

[Gary]

Boob action?Boob action? I didnt see no Boob action.....3 times!!!!!!!!LOL:popcorn2:

[hide]

I have been told that my lipos would explode if they got wet. Obviously people assume that the water will conduct, they will short and explode. My lipos got wet, I removed the heatshrink, cleaned them up and still use them.

[sailr]

I suspect these stories are put out there by the die-hard nimh users who are too cheap to move to lipos.

I have seen lipos submerged for several hours before we could dive down 20 feet and locate the boat. Dried 'em out, they work fine!

This explode if wet B.S. is just that..... B.S.

[Flying Scotsman]

Andy... Little to much boob action in the picture Sir. I enjoy slammin jugs as much as the next guy:thumbup1: keep in mind it's a family forum bud.
Tommy G

Tommy, if mum takes the kids down to the beach or hotel pool, guess what the kids see, lots of lassies in bikinis including mum. Now in Europe they would see the lassies with bikini bottoms only or no clothing :tongue_smilie:

Douggie

[Fluid]

Incorrect. Actually a salt solution is no where near a direct short.

Actually salt water behaves exactly like a resistor does by creating a short between the pack leads. It may take a long or short time to discharge a pack depending on the salinity of the water. Distilled water is a non-conductor and will never discharge anything. But then we don't run in distilled water, much of the surface water in the US is filled with various ions which will help to dischage a submerged pack over time.

More info:

http://radiocontrol.wikia.com/wiki/Lithium_polymer If a battery's outer case is punctured, the lithium inside is highly volatile and will react violently with water. Such a pack may be disposed of by first discharging it with an automotive lamp, carefully slitting the outer skin of each cell with a razor blade or X-Acto knife and neutralizing it for several hours in saltwater. Since the chemicals are considered environmentally friendly, the pack may then be disposed of in the regular trash. Note that some cells might react to any discharge attempt with further bloating. Such cells should immediately be placed into a saltwater bath. It can take several days for a fully charged cell to deactivate in saltwater. If your cell is bloated, excercise caution when opening the outer foil. Using a needle on a stick is advised. Only puncture the outer skin, do not push the needle all the way through the cell. It is advised that this should be done with the cell already submerged in the saltwater bath.


.

[sailr]

Aw c'mon. Do you not allow your children to go to the beach? Jeeez.


Andy... Little to much boob action in the picture Sir. I enjoy slammin jugs as much as the next guy:thumbup1: keep in mind it's a family forum bud.
Tommy G

[SJFE]

Tommy, if mum takes the kids down to the beach or hotel pool, guess what the kids see, lots of lassies in bikinis including mum. Now in Europe they would see the lassies with bikini bottoms only or no clothing

Douggie
Edit/Delete Message


Quite true my friend:smile:. While not being in charge of or responsible for the beach dress code..... I am charged with seeing the content of the forum conforms to a family oriented standard.

[sailr]

Methinks thou dost protest too much.

[Rumdog]

Andy... Little to much boob action in the picture Sir. I enjoy slammin jugs as much as the next guy:thumbup1: keep in mind it's a family forum bud.
Tommy G

lol, all is see is hot chick in a bikini, it's def. not *!***!***!***!**. I could drive down to the local beach in the summer and see the same thing, well beside the fish

[SJFE]

I take it I'm the only one who fails to notice the a fore mentioned garment is transparent.

[Diegoboy]

she may be wearing a bikini, but one that is slightly transparent as the one in your avatar is prohibited in virginia beach ( as is thongs) so please respect your moderator and take it down.
What is more important here? The short lived display of your risque avatar? or your free use of this site?

[sailr]

ya got better eyes than me or perhaps more of a prurient interest?


I take it I'm the only one who fails to notice the a fore mentioned garment is transparent.

[TRUCKPULL]

but one that is slightly transparent is prohibited in virginia beach ( as is thongs)

Virginia Beach - You have got to be kidding.:doh:

In Ontario Canada it is legal for a woman can go topples any time she wants,
Thongs - the smaller the better.

Larry

[Chop]

ya got better eyes than me or perhaps more of a prurient interest?

I see it too, AND LIKE IT!!!:rockon2: But I have to agree with SJFE that it is not appropriate for this forum.

Maybe you can email me the picture so I can do more research on the validity of the transparency of the garment.
:buttrock:OH YEAH!

[Jeff Wohlt]

LOL...

Just forward in large format to me, Andy. All I see is a bikini top but I continue to look so hard my eyes hurt. I am going to go get better reading glasses.

You should see what happened on RC Zone...now that was bad!! The moderators were told several days about it and it was still there yesterday....more than bad.

[egneg]

Virginia Beach - You have got to be kidding.:doh:

In Ontario Canada it is legal for a woman can go topples any time she wants,
Thongs - the smaller the better.

Larry

The strip joints are more conservative than the beach! ... so I have been told.

[Chop]

Did someone say there was a fish in the picture?:confused2:

[TRUCKPULL]

The strip joints are more conservative than the beach! ... so I have been told.

I am not talking about the strip joints.

It is Legal for a woman to go topless in public here.

Larry

[properchopper]

I haven't seen anything personally but I did read all the horror stories about how they went up in flames if you looked at them funny.

The proper(chopper) way to dispose of a lipo [ as witnessed in this scene at the 2008 NATS]
is to encourage (dare) an AZ gentlemen racer to hammer a big nail in it. We really enjoyed the toxic fumes while bathing in the warm glow of the pyrotechnics. :crying:

[andym]

Me thinks the bad rap that lipo's get is the same as the bad rap my avatar is getting. Miss information from people with know all attitudes who try to control the world..............
No seriously batman, I changed it because obviously the fish were to big. Now if you want nudity and sex scenes just watch any American prime time TV show!!

[egneg]

Me thinks the bad rap that lipo's get is the same as the bad rap my avatar is getting. Miss information from people with know all attitudes who try to control the world..............
No seriously batman, I changed it because obviously the fish were to big. Now if you want nudity and sex scenes just watch any American prime time TV show!!


Sounds like sour grapes!!!

:eek:

[sailr]

Much ado about nothing. Move along..nothing to see here.

[domwilson]

PKNAONxFU4U

[ozzie-crawl]

is it just me or is it strange that i start a thread titled "lipo misinformation"
and half the responses seem to be that i believe lipos will explode if getting wet :confused2:
the other half seem to be arguing if the women in andys avatar has a see threw bikini or a big fish.
now if everyone is going to avoid the real subject i will bring it up, are we alone in the universe
personally i am sick of being abducted by aliens from different planets,and what is it with this anal probing obsession they have.

[SJFE]

know all attitudes who try to control the world..............

The FCC can worry about tv. Just doing my job here nothing personal.

[sailr]

You gotta stay off of GAYDOR.


is it just me or is it strange that i start a thread titled "lipo misinformation"
and half the responses seem to be that i believe lipos will explode if getting wet :confused2:
the other half seem to be arguing if the women in andys avatar has a see threw bikini or a big fish.
now if everyone is going to avoid the real subject i will bring it up, are we alone in the universe
personally i am sick of being abducted by aliens from different planets,and what is it with this anal probing obsession they have.

[egneg]

...

[domwilson]

I've been noticing that about many threads as of late. It's a combination of a number of factors. I was just waiting for the train to jump the track on this thread....

Anyways there is a large number of misleading stories out there about lipos. From the initial purchase of brand and capacity to disposal with disaster stories in between. Although some lipo stories may be true, I think it's more of a "One Up"
on the stories. It's sort of like showing people a new car...someone always has a friend or a cousin that has something better..

[SJFE]

We are lucky to only get the random thread now and again. I remember years back when packs where first used. It was armageddon. Full blown knock down drag outs on forums with posts ranging from safety to cost and everything in between.
Ahh the good old days:olleyes:.

[sailr]

When lipos first hit the scene a few years back, they were not very stable. The old horror stories, even then, were remote. They were the result of misunderstanding of the care and feeding of lipos and overamping, overcharging, overdischarging, etc. There has been tremendous improvement in the composition and quality control of the packs in the past two years.

In general, those of us using lipos have paid attention and become much more educated regarding their use. I started using lipos in 2003-2004 and have NEVER had an incident. BUT...I charge them right and use them right.

For what it's worth, I have seen nimh packs blow up also!

[egneg]

I have only had 1 pack puff and I bought the pair used so their back ground is questionable at best.

[SJFE]

I have seen nimh packs blow up also

I have had Ni cells pop... The IB4200s where just plain junk toward the end. Now the 3600s they where damn fines cells




http://i42.photobucket.com/albums/e343/STOAK/DSC00506.jpg




Man this picture brings me back....

[domwilson]

Now that lipos have proven themselves in this hobby, it's just a matter of brand, "C" rating, mah rating, etc. There is, of course, a lot of misinformation out there. Especially with recommendations.

[FloatDaBoat]

Actually salt water behaves exactly like a resistor does by creating a short between the pack leads. It may take a long or short time to discharge a pack depending on the salinity of the water. Distilled water is a non-conductor and will never discharge anything. But then we don't run in distilled water, much of the surface water in the US is filled with various ions which will help to dischage a submerged pack over time.


.

I performed a little resistance test on H2O. I taped two steel washers ~ 3/8” (0.375” or 9.53 millimeters) apart on the bottom of an old Gladware plastic food container. I then proceeded to make the following measurements with my $20 digital multimeter with the test probes attached to the washers, which were covered by:
4 ounces of supermarket distilled water - 112.4 K Ohms
4 ounces of tap water - 5.15 K Ohms
4 ounces of tap water with 1 teaspoon of table salt stirred in - 1,169 Ohms (1.169 K)
Not very scientific; it should suffice to compare conductivity between the three.

[tsenecal]

myself and several of other members of the subcommittee (yes its real, check it out http://subcommittee.com ) run our submarines with Lipos in the wet, for several hours at a time.

water by itself won't kill a healthy Lipo.

[Gary]

Well at least he changed the picture! Andy.........you are my hero!!!!!!!!!!!!!!!!!!!!!!!! LOL

[FloatDaBoat]

I have had Ni cells pop...


Anything like these ???

[domwilson]

I had a Nimh burn up like that.

[Flying Scotsman]

The point is use the manufacturer's instructions on all facets..charging..storage..disposal etc.
If you follow those guidelines, you will not have a problem. If the battery gets wet, it is corrosion on the tabs that will cause problems. There have been many silly stories on battery powered equipment. The other sources of power are probably more dangerous gas/petrol. nuclear,etc. and Andy's avatars.

Douggie

[domwilson]

The point is use the manufacturer's instructions on all facets..charging..storage..disposal etc.
If you follow those guidelines, you will not have a problem. If the battery gets wet, it is corrosion on the tabs that will cause problems. There have been many silly stories on battery powered equipment. The other sources of power are probably more dangerous gas/petrol. nuclear,etc. and Andy's avatars.

Douggie

And do your research. See if others have had problems with the brand you are looking to purchase.

[astecme]

Modern Lipo's are fine if you obey the charge/discharge rules. Water will corrode the internal connections so it is advisable to sela the packs with silicon.

With old packs they used to "explode" well a big flame. Lithium is flamable but there is so little of it in modern lipo's it should not be a concern. With modern lipos you can drive a nail through the pack and you will only get a small fizz.

Lipo's are more stable than NIMH cells which vent hydrogen when abused!

[Steven Vaccaro]

All I have to say is just because it hasn't happened to you, doesn't mean it isnt true.

All sources of stored energy are dangerous. Try to store more then fits and boom.

[Doby]

With modern lipos you can drive a nail through the pack and you will only get a small fizz.




Wrong:flashfire:

[sailr]

Please don't talk about how safe they are these days and that you can drive a nail through them! I think you are confusing lipos with the LiFE (lithium iron) batteries such as A123's. These are NOT lipos! They also don't have as much capacity, are big and heavy, etc.


Modern Lipo's are fine if you obey the charge/discharge rules. Water will corrode the internal connections so it is advisable to sela the packs with silicon.

With old packs they used to "explode" well a big flame. Lithium is flamable but there is so little of it in modern lipo's it should not be a concern. With modern lipos you can drive a nail through the pack and you will only get a small fizz.

Lipo's are more stable than NIMH cells which vent hydrogen when abused!

[properchopper]

With modern lipos you can drive a nail through the pack and you will only get a small fizz.


Please see post # 35 for picture of small fizz. :smile:

[Doby]

Some more "Small Fizz"

http://forums.offshoreelectrics.com/showthread.php?t=3313