Trouble with Li-Pos?

[Sheldon Holy]

I've never had any issues with Lipos. That is, the thing randomly blowing up.

I've intentionally blown up too many to count.

[Mike Etheridge 1]

I have recently bought my first lipo,a 3 cell unit. I have a battery tester that is also a balancer plus a cheap Parkzone charger / balancer and to date everything seems OK but under no circumstances will allow the Lipo into the house.

MJE

[Joe Beavis]

Vecchio touched on a very important point - protection of Lipos by design! As you arrange the battery installation, think about what will happen if the fuselage stops from 60mph in two inches! When I convert an ic design to electric, I make a ply "coffin" that passes through F1 an F2, with big enough cross section to take the battery plus some velcro. I mount the motor very robustly on the front. If you ensure the inside of the box is clear of any lumps or screws then it becomes as good a survival capsule as you can make. It also facilitates fine tuning of the motor position for the cowling, and the battery can be moved inside for balance. I am sorry to say that this system has been thoroughly tested and preseved Lipos - even underground!

Joe

[FilmBuff]

Eight years of use and never had any problems at all. No fires, no smoke, no puffing.

So far.....

[Former Member]

[This posting has been removed]

[John Olsen 1]

I've written a couple off by damaging them, but they did not catch fire. It was just that I felt it unwise to continue using a banana shaped lipo, and in the other case, a lipo that was now about 3/4 inch shorter than it had started out. That was despite there having been a block of foam in front as a shock absorber.

I have had an ESC catch fire, that was quite spectacular. But it had an excuse, it had been reused from one of the earlier crashes. It had done a few flights after the crash too, but I guess there must have been a crack in the board or something like that. Luckily it went on the ground while I was doing a check with the Wattmeter, so it was easy to pull the leads off.

John

[Rich too]

never had a problem (touch wood), how do you dispose of them? I have a damaged one. does the local recycling centre take them?

Rich

[David Davis]

Mine does. So does my local branch of Morrisons.

[Biggles' Elder Brother - Moderator]

The conventional method is to discharge them as far as you reasonably can, a torch bulb attached is a good way to do this. Make sure the battery is in a safe place while you do this as there is a small chance of fire, so on tile/brick safely out of the way of anything flammable. Once its a fully discharged as possible (down to tens of millivolts), separate the cells and score their outer covers with a insulated knife then place the battery into a bucket of salty water. Leave it there for at least 48 hours. They are then fine to dispose of in the conventional rubbish.

BEB

[Bob Cotsford]

I think you will find most local authorities would prefer you to take them to a recycling centre rather than putting them in household waste.

[Biggles' Elder Brother - Moderator]

I'm sure what you say is true Bob. However, strange as it may seem, the "Waste Batteries and Accumulator Regulations - 2009" places no duty what so ever on local authorities to provide recycling facilities for batteries! I find that an amazing situation.

I'm sure my local authority is not alone therefore in providing no such service - except for car batteries. So, unless I drop them in the battery bin in Sainsburys - which only really seems to deal with alkaline and maybe NiMH - I don't really have another option and at least what I have described above makes them electrically safe.

BEB

Edited By Biggles' Elder Brother - Moderator on 29/05/2014 12:24:52

[Pete B]

There's been plenty of discussion on this before - just search here on 'disposal'.

I'm with BEB, rightly or wrongly - just doesn't seem right to drop a LiPo, discharged or otherwise, into a bin inside a supermarket.....

Pete

[Rich too]

Mmm, in that case I will have to check with them. My centre is less than 5 mins away but I seem to recall just Alkaline being catered for....

If not, time to get the bucket of salt water ready!

Thanks for the info.

Rich

[The Wright Stuff]

Posted by Pete B - Moderator on 29/05/2014 12:31:20:

I'm with BEB, rightly or wrongly - just doesn't seem right to drop a LiPo, discharged or otherwise, into a bin inside a supermarket.....

Hi Pete,

That comment is kind of ironic, I suppose, in the sense that we are trying to persuade ourselves that it's safe to keep LiPos in our houses, but wouldn't put them in a bin at the supermarket. Our logical brain tells us that they are safe, but our subconscious still isn't comfortable, somehow...

TWS

[Pete B]

I know what you mean, TWS, but I'd like to think we take a bit of care with storage, handling etc whilst they're under our control as we are well aware of their potential.

The fact that, in the replies to the poll so far, there doesn't seem to have been one response citing spontaneous combustion in normal circumstances, seems to suggest that they don't present a significant risk when handled and used properly.

My concern is when they end up in a bin or handled by people with no knowledge of that potential....

Pete

[Ian Jones]

None of mine have ever smoked but I've seen others do it.

One chap damaged a lipo in a crash and stuck his thumb nail in a shallow cut that had been caused top see if was alright. It wasn't, sparked a bit and burnt his nail - nothing serious though.

Seen a good number of ESCs go up in smoke too.

[John Lee]

In the early days of Lipo's I had a small (about 10Mah) 1 cell blow up on me when I assumed another manufacturer's charger with the same connector would be suitable. Made enough of an impression on me to fully focus the mind every time I've charged a battery since.

[The Wright Stuff]

Posted by Pete B - Moderator on 29/05/2014 13:59:14:

The fact that, in the replies to the poll so far, there doesn't seem to have been one response citing spontaneous combustion in normal circumstances, seems to suggest that they don't present a significant risk when handled and used properly.

Pete, just a thought, but do you or the mods have any access to numbers regarding how many of us log in regularly enough to have participated? By that I mean, can we estimate what percentage of model flying forum members have participated in the poll? I guess where I'm going with this is that 155 responses (so far) isn't actually that high a number in the sense that I wouldn't bet my house on a 1 in 155 chance of losing it: it would be good to know whether the data can be statistically significant in terms of assessing the risk... Similarly, I'm not sure I believe that 96% of model flyers use Lipos...

Cheers.

[john stones 1 - Moderator]

Looks to me so far that only impact or misuse results in failures TWS ?

Also bear in mind a lot of us that have posted use an awful lot more than one lipo, so the 155 figure could be viewed differently if say we had an average of 6 or whatever the number may be. And if I where to say how few incidents amongst 60 club members the figure would look even more reassuring. ....so far

John

[Bob Black]

I have Nye on twenty Lipo`s

Only had one majorish problem (of my own doing I must confess), after a heavy arrival saw a hint of smoke from 3s2200 ,thought it was a bit risky trying to get to Deans connecter to pull apart, then without thinking cut through twin cable with side cutters. That did make the sparks fly, Luckily the side cutters are well insulated.

Bob

[Bob Cotsford]

Posted by Biggles' Elder Brother - Moderator on 29/05/2014 12:24:08:

I'm sure what you say is true Bob. However, strange as it may seem, the "Waste Batteries and Accumulator Regulations - 2009" places no duty what so ever on local authorities to provide recycling facilities for batteries! I find that an amazing situation.

I'm sure my local authority is not alone therefore in providing no such service - except for car batteries. So, unless I drop them in the battery bin in Sainsburys - which only really seems to deal with alkaline and maybe NiMH - I don't really have another option and at least what I have described above makes them electrically safe.

BEB

Edited By Biggles' Elder Brother - Moderator on 29/05/2014 12:24:52

BEB, I wasn't trying to say it was a national rule but certainly a lot of councils now accept all battery types. Sorry if it came across a bit combative, too many 2:00 am call-outs!

Your suggestion will certainly make them safe too.

[Speedster]

Lipo fire due to wrong setting on charger..

6 cell instead of 5 and no use of ballancer cable.

At 20 sec. in video:

Cheers

Soren

[Biggles' Elder Brother - Moderator]

Absolutely no problem Bob - I didn't see your post as combative at all. You are quite right many council may well offer facilities - and if they do obviously it would be wise to use them. Sadly for me my council rarely offer anything that isn't demanded of them under threat of execution! . (A bit unfair actually, because they are actually quite good to deal with over our flying site - but you know what I mean!)

TWS we can get data like the number of unique logins per day etc. And while it varies up and down a bit I believe it runs at about 5,000/day.

So 170 is not enormous, but for the couple of days the poll has been up - and if you say 50% of modellers fly electric then its not too bad - a little bit under 1 in 10 have responded so far.

Overall the typical response rate to a poll on here is of the order of 4-600, the previous one on Tx makes was very much more but that was exceptional.

I would suggest that a sample of 4-600 is actually fairly large statistically and probably enough to form a reasonable picture.

But of course we must always remember that these polls are really just a bit of fun. Yes they can give you an idea of what is happening, sometimes a fairly accurate idea, but I'd hate anyone to draw the conclusion from this poll that all the talk of Lipo's burning is just scare mongering.

I think what this poll will show us (and I'm only speculating here) is that Lipo incidents are actually quite rare, and that when they do happen they are fortunately often of the less dramatic and potentially dangerous type. So overall we may well draw the conclusion that Lipo's are a "safe" technology. But,....I would suggest that that is very much down to our generally good practices. Incidents are infrequent because we treat Lipo's with respect and care due to the fact that we see the potential danger. If following a basically "null poll" we started to be more reckless and lost that respect and care, because we'd became blasé, then I think we might start to see a different story.

BEB

[Pete B]

Posted by The Wright Stuff on 29/05/2014 15:16:17:

Pete, just a thought, but do you or the mods have any access to numbers regarding how many of us log in regularly enough to have participated? By that I mean, can we estimate what percentage of model flying forum members have participated in the poll? I guess where I'm going with this is that 155 responses (so far) isn't actually that high a number in the sense that I wouldn't bet my house on a 1 in 155 chance of losing it: it would be good to know whether the data can be statistically significant in terms of assessing the risk... Similarly, I'm not sure I believe that 96% of model flyers use Lipos...

I wouldn't know how many daily hits we get on the site, TWS, but at a guess I'd say it's probably in four figures. There's probably as many or more who lurk as regularly post here - for example, of the 155 so far, only 30 or so have added a comment.

If we assume (dangerous, I know) that the overwhelming majority who have voted so far have no experience to relate or axe to grind, then I'd say it probably reflects the fact that most users don't experience problems. Now, given also that the posters and lurkers on this site are of the ilk who want to learn and do things 'the right way', I'm not surprised most are using LiPos in a safe fashion. Whether that also applies to those who choose not to visit us, I know not, but I suspect it does.

A sample of 155 in how many thousand RC flyers in the country is never going to give an accurate answer in a poll but I'd say that the trend so far shows fewer problems in practice than we may have thought.

Pete ( GCE O Level Maths Grade 5....)

[Erfolg]

It appears to me that the registered results are pretty reassuring. As has been observed by others, users of Lipos would normally have several in use at any one time and over a period of some years the numbers will almost certainly be higher than most of us remember.

The failure rate would be significantly less than the 1% unexplained rate, as that applies to users, rather than the number of lipos.

Being a little bold, I would also conjecture that the unexplained instances, often have a cause other than spontaneous.

I do remember being here some 30 years ago with Nicads, where there many reports of exploding cells. Where there were also dire warnings that these cells were "the spawn of the Devil". The reality was abuse of the poor things, being connected to Pb acid cells charger, or attempts to charge from the mains in one case, with a dropper lead. N wonder there were problems.

I would suggests, as the chargers improve in capability and inbuilt safety features and users increase their knowledge and respect for the cells, a lot of the issues will become history. That is without further improvements in the Lipos themselves.

Edited By Erfolg on 29/05/2014 21:52:32