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I've revived a zero volts 3S LiPo.

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Wingman27/05/2013 19:42:57
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Nine months ago I crashed my Flying Wing into a wheat field and was unable to find it. Last week the farmer returned it having ploughed it up and, of course, it was in a really bad way, squashed, torn and with completely rotted ailerons. However the receiver, esc and battery were still in their compartments and still connected together so the battery, a Gens Ace 2200maH 55C was, of course, at absolute zero volts but was in excellent physical condition apart from where a mouse had sampled the insulation where it exited the compartment. I decided I would try and revive the battery, more as an experiment than with any real hope of success. Of course, with zero volts no charger would look at it so I connected another 2200maH battery in parallel with it - there was a spark when connecting so that was a good sign of possible life! I left them overnight and in the morning I was amazed to find both batteries reading 11.4 volts - effectively the good battery had balance charged the 'patient'. Next I connected the 'patient' to an 800ma 3 cell balance charger that had come with an RTF model and once again left it overnight.
The next morning I had 3 'greens' on the charger and 12.6 volts on the battery - looking good. Next I connected it to my Pro-Peak Constellation charger set to discharge to 2.7 volts per cell and the battery supplied 1805ma - a bit down on capacity but not bad. I then charged it with my Hyperion EOS0610i and it took a charge of 2045ma - near as dammit full capacity! So was it still a 55C? - well I flew it in my current wing which pulls 50A at full thrutch and it climbed vertically to the cloud base - normal performance for this beastie and gave me the normal 10 minute flight time after that. So, as far as I can determine, a LiPo battery which was held at zero volts for 9 months has been restored to full capacity, something which I had always been led to believe was impossible - a testament to the quality of Gens Ace batteries if nothing else!

Chris Bott - Moderator28/05/2013 11:53:47
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Well done Wingman, that sounds quite remarkable.

However I think a rider/warning needs to be added, along the lines of "Don't try this at home"

Unless you fully understand what you're doing, and the dangers and the precautions that should be taken, this could be a very dangerous activity.

For example, alll conventional wisdom at this time, says not to leave LiPo's unattended while charging.

Did you parallel the two batteries via the balance plugs? If not there is certainly the potential for one of the "receiving" cells to be overcharged, with disasterous consequences.

I think I'd also have been concerned about killing a second battery too.

Well done though, it just shows that we may be writing the odd pack off preaturely.

kc28/05/2013 12:56:43
6032 forum posts
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Interesting!

If the Lipo had been declared useless what is the way to dispose of it.....:-

a. the official way

b. the practical way ( if the official way is not practical )

Bob Cotsford28/05/2013 13:03:51
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a) dunk it in salt water for a few days to discharge it then take it to the council recycling centre.

b) place it on a hard surface and wack it with something sharp - be sure to invite the club round to watch. 999 ready dialled on a mobile may also prove useful.

John Hickson28/05/2013 13:24:04
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I did something similar with a 3S 2200 I left plugged into a battery monitor (doh). It was completely flat and my charger refused to do anything with it. I put it on a 9v NiMh charge for 5 mins, then switched over to a normal LiPo charge and it worked. I've used the pack countless times since

John Laird28/05/2013 14:11:14
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connecting a "full" battery to a flat battery is almost like shorting the full battery - so it is little wonder you got a spark connecting the two - you were lucky there was enough resistance in the flat battery to prevent a dead short and  blowing up  the good one -definitely not a recommended practice.

John Hickson has the right idea - get something into the battery so that the normal lipo charger can see it and charge safely if it will take it

john

Edited By John Laird on 28/05/2013 14:13:18

kc28/05/2013 14:45:37
6032 forum posts
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For those who dont yet understand aeromodelling club humour, Bob was obviously joking about method b but what about method a? Do the council recycling centres have a section for Lipo? Should we just mix them in with car batteries, alkaline cells, nicads etc at the dump? Do councils accept Lipos as normal household waste or do they make some extortionate charge if we tell them exactly what they are?

Toni Reynaud28/05/2013 15:01:15
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I believe the accepted wisdom is that after discharging they go for landfill (AKA the dustbin) rather than recycling. That's where mine have always gone. Also I slit the cells open (carefully) after discharge and leave in the salt water for a day or two to ensure that they are completely inert.

Bob Cotsford28/05/2013 15:13:17
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I always thought you could dump them in the dustbin after discharging, but someone (sorry, can't remember who) put up a link explaining that they should be handled seperately.

John Olsen 128/05/2013 23:36:08
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I've had a 460mAh 2S go completely flat after I inadvertently left it connected in the model for over a week. When I connected it to my charger ( a Turnigy Fat Boy) it told me it was undervoltage, which at zero volts I guess it was. I was about to disconnect and discard when a message came up about "going into recovery mode". So I left it going...it charged the battery up, and it seems OK now. Of course there is no way of knowing if I will get a normal number of cycles out of it. So it seems that at least some chargers are set up to try to fix undervoltage cells. I presume this would be done by charging at a constant rate until the voltage comes up into the expected range.

John

Pat (rActive) Harbord28/05/2013 23:55:30
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My local tip has a bin for laptop and power tool batteries. Is there much difference between li-ion and li-poly? I must admit to binning dead lipos after discharging and splitting in the regular trash.

Olly P29/05/2013 13:25:07
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Bob - you are correct, Toni - please don't put them in the normal bin!

Batteries are a type or WEEE controlled waste, and especially so LITHIUM based batteries. these need to go to any battery recycling bin after being discharged (no need to split open).

From there they will go through a recovery stream process and the Lithium and other chemicals will be recovered and reused. Putting any heavy metal into Landfill is a 'bad thing' it can cause huge problems and contaminate water supplies etc.

Olly (who deals with WEEE on a regular basis...)

Pat (rActive) Harbord29/05/2013 22:28:22
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Thanks for clarifying Oli. Makes perfect sense

John Olsen 129/05/2013 22:41:47
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Olly, while you are right about the disposal, Lithium itself is not what we would normally call a heavy metal. It is after all only number 3 in the periodic table, and is the lightest of all elements that are solid at standard conditions. It would be light enough to float in water, except that it would react rather violently instead. Of course it is still definitely not something that you would want to find in your drinking water!

John

TheFlyingCrust30/05/2013 00:31:07
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Hi Olly. Lithium is not a heavy metal. In fact it is the lightest metal on the periodic table. Specific gravity of about 0.54 (SG of water is 1)However everything else you said I agree with. Take to the recycling centre and don't landfill them.

Olly P30/05/2013 08:01:06
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My apologies I was doing an 'on the fly' translation of a french article at the time and got the 2 terms mixed up - somewhere in my report for work will be 'materials classed as contaminants' rather than heavy metal!

Lithium is of course a MCaC not a Heavy Metal. Slayer, Manowar and Metallica are heavy metal....

(runs to avoid thrown objects...)

 

Edit  - forgot to add, you can take lipos to the battery bins in most shops too - they generally go into the same streaming facility as the stuff from the tip/recycling centre/refuse site.

The cost for this is paid by us, your local electrical manufacturers (and importers), we pay per ton of what we create to cover the cost of its disposal at end of life, but as there is no pot of money, we are actually paying for the stuff being disposed of now, and those producing in the future will pay for our stuff to be disposed of. We are also responsible for disposing of any WEEE we generate correctly (i.e. the things we replace) and paying the cost of this (normally a profit due to the metals reclaimed).....

Edited By Olly P on 30/05/2013 08:05:27

Phil Winks30/05/2013 17:26:05
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So aving read through this am I right in thinking that a lengthy time in salt water to ensure a completly flat bty and disposal at the council recycling centre?

This does indeed fall inline with whart I believe I read somewhere in a BMFA mag some years ago

Phil

Peter Beeney30/05/2013 18:41:39
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When the very first lipos came on the scene the charger had quite a narrow charge voltage ‘window’. It had to see at least 3.3 volts/cell before it would start charging, so I made a Y lead that enabled me to parallel a charged battery with a discharged one. The higher voltage was then enough to fire up the charger, then the charged pack could be taken off if required. We’ve also revived the odd pack that has been left for months and gone down to zero volts, and as I’ve described before, even brand new packs with cells that are reluctant to start delivering the watts. A standard charger throws these out as faulty. Although more often than not a dud cell is a dud cell, but I’ve always thought it’s worth at least making sure, on the odd occasion they will come back to life. As said before, I’m fortunate in that I have a variable bench supply, so I have total control of volts and amps; and this does mean, too, that I can easily get to spots that standard chargers can’t reach.

With regard to disposal, the EU Waste Battery Directive does say all battery material must be re-cycled, although I’m sure there is some leeway on that. Our local Civic Amenities Site, a small rural location, is a virtual paragon in waste management. There is a bin, about the size of a large dustbin, with a lid, and I’m told this is for the disposal of any types of small batteries. There is a larger cage for car batteries and any lead-acid types. The turn over rate is phenomenal, because although it’s always busy, the bins are always clean and fairly empty. I’ve always tried to avoid putting any cells into household rubbish, anyway, and now it’s very easy not so to do!

I’ve always thought that, had the battery manufacturing industry got it act together in the first instance, they would have started to re-cycle nicads back then and now they would still be be freely available; and who’s to say that sooner or later lithiums, and others, might also start to look a bit suspect? I’d consider that any cell or battery, if discharged to completely flat and then a short in the form of a piece of wire, say, is left across the terminals, is never really going to come to much harm. A modern re-cycling plant must be well capable of dealing with any type and condition of any battery, lithium is not going to be a problem. As it happens, I’d be surprised if most batteries don’t just go in the bin in the condition they were removed from the appliance they were nearly powering.
Of course, it’s always possible that the whole lot is just tipped into landfill anyhow!

Just taking a quick look at some consumption figures, the demand worldwide in 2012 for lithium was 125 thousand tonnes, of which 50 thousand tonnes was used for battery manufacture. By 2025 it’s estimated that the demand will exceed 400 thousand tonnes, of which 250 thousand tonnes will be absorbed by batteries. If we very hypothetically assumed that the average weight of a LiPo cell is 100 grams, and 25 grams of that comprises of actual lithium, then that will equate to 10 billion individual cells. This seems to me to indicate the fact that at some point some of this stuff is going to have to be used for the second time around.

I don’t really know what the actual weight of the lithium is, as it’s lithium-ions that are in the cells, the metallic lithium proved to be too difficult to handle. But whichever way, there is surely going to be a fair few lithium batteries around…

I have to admit, I’ve never fully subscribed to the ‘complications’ of lithium usage. If these things are truly as dangerous as what some of the literature would have you believe, then I’m not sure that I’d want to contemplate using them much anyway. When you consider how many lithium cells there are in circulation now, why does it seem that in general it’s only modellers that have any problems? Does this point to operator error? I don’t have any problems with how anyone chooses to to charge/discharge or generally look after his LiPo’s, but I think there is a certain irony to the fact that when someone is earnestly telling me that I can’t treat my packs the way I do, all the time there is a mobile phone in his trouser pocket containing it’s LiPo just on the point of bursting into flames!

Just a few more rambling thoughts…

PB

John Olsen 131/05/2013 11:49:43
446 forum posts
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I gather Boeing has had a few problems with them too. Although my electric car builder friend is a bit scathing about that, apparently they were asking for trouble in the first place. Actually the phone and laptop people had a few woes in the early days too. But then a tank full of petrol is pretty dangerous too. Anything that stores energy at a reasonably high density is potentially dangerous. People have been killed by springs.

I think few people other than modellers expect to charge their batteries in less than half an hour and then discharge them in less than ten minutes, as well as occasionally thumping them into the ground rather hard. I have to confess I bent a 4200mAh 6S like a banana. I guess it is to the credit of the maker that it did not leak or burn up, it came down from about 300 feet rather quickly.

John

Peter Beeney31/05/2013 13:56:13
1554 forum posts
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Yes, the Nokia phone batteries that went on fire, I think around 2003 - 04, on investigation all proved to be fake. The Vice Chairman of Nokia made a fairly forceful statement afterwards, saying that the import system needed to be tightened, apparently these had crept in under the radar of the very people that were looking for counterfeits!

There was also the laptop that spectacularly went on fire at a Japanese computer convention. It was decided that very small particles of metal in the batteries was the culprit, and this resulted in a massive recall of batteries. However, some manufacturers took a chance, and didn’t bother. The report that I read sometime later said that not any of these original batteries had caused any fires anywhere else either, and so there was some speculation as to exactly how big the problem actually was. With hindsight, it now seems like a nice coincidence that it happened at a meeting with all the executives sitting around, and a camera set up to record the event…

The recent Boeing incident is interesting, inasmuch that as so far the public reports go, or at least the one’s that I’ve read, anyway, say that so far they don’t know what caused the problem. It seems that as yet they are unable to blame the batteries. We have a couple of airline pilots amongst us, one is a Boeing Captain, I’ll see if he has a take on it. But I suspect that unlikely, I’m sure any opinion will be just an opinion.

I’d certainly agree about the petrol. It has been said, I believe, that if cars were invented today, they would not exist because they would not be allow to carry petrol. And I wonder just how many incidents there’s been using jump leads? There has been a few explosions…

I think your statement about charging and discharging is also very true. A comparable industrial situation would be properly geared up to cope. Also considering that batteries are a consumer item with a very high turnover rate, (encouraged!), mostly because very few customers have any means of checking the quality and the capacity, then perhaps our lithiums do not fare too badly.

Apologies for going somewhat off track, but hopefully still within general guidelines.

PB

Edited By Peter Beeney on 31/05/2013 14:00:36

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