View Full Version : Lipo fire
What a plonker.
http://www.youtube.com/watch?v=6M5ftkN9PtY&feature=related
Chequered Flag Racing
30-11-2010, 05:42 PM
What a plonker.
http://www.youtube.com/watch?v=6M5ftkN9PtY&feature=related (http://www.youtube.com/watch?v=6M5ftkN9PtY&feature=related)
:confused:
did you bother to read the text from 6 seconds in as well as watch the video?
it's a demo of what can happen if lipo's go poooooof
you plonker :p
There are safer ways of doing it.
How to give LiPo's a bad name....
He's got it in a steel box, away from anything flamable. He could have worn some gloves but it looks like he knows what he's doing.
Its not like he's doing anything that can't happen in a really bad crash and this shows how volatile lipo's are. Theyre not toys and anyone who uses them does so at their own risk.
People need reminders like this. Anyone that feels like complaining about having to use lipo sacks should think again.
mark christopher
30-11-2010, 08:56 PM
He's got it in a steel box, away from anything flamable. He could have worn some gloves but it looks like he knows what he's doing.
Its not like he's doing anything that can't happen in a really bad crash and this shows how volatile lipo's are. Theyre not toys and anyone who uses them does so at their own risk.
People need reminders like this. Anyone that feels like complaining about having to use lipo sacks should think again.
tosh..........ALL power sources pose a risk, its how you use em, would you fill your big car up with petrol and a fag in ur gob?
no body did sh1t when IB's were exploding,
EXPLODING NiMH 23/43 CELLS
No doubt you will have read or heard the stories of batteries exploding and that the Norwegian Federation has temporarily suspended all electric racing. We have been monitoring these ‘incidents’ but obtaining hard facts is not easy, making it difficult to draw any meaningful conclusions.
Given that there are thousands of cells in circulation, such incidents have been exceedingly rare in the past. The only serious incident that has occurred to date in UK was when a receiver pack blew, that has permanently damaged a person’s eyesight. Although there will have been more injuries caused by scalpels or super glue in eyes than caused from exploding cells, you still need to take care!
The NiMh cells have a chemistry that allows the cell to 'self-discharge' over a relatively short period, (days as opposed to weeks). Lately, some of the 4200 cells seem to self-discharge more rapidly than other/previous versions. More importantly the amount each individual cell within a pack discharges varies (i.e. cell 1 might be .9v, cell 2 .8v, cell 3 .9v, cell 4 .7v, etc.)
If charged in this state, some chargers will not know when to stop the charge process, as some cells are demanding to continue with the charge, whilst others could be over charged. It is also important to control the delta peak (voltage drop-off after completed charge) to a low value when charging. Once the cell has achieved full charge, any further charging will produce gas. The cells have a pressure vent, but if that is blocked or not working, the gas pressure could cause an explosion.
High charge rates will also produce more gas and reduce the cell’s useful life. It is possible that internal gas pressure may cause distortion to some internal parts that could result in a short circuit within the cell. An internal short circuit combined with gas pressure is likely to be a 'big bang'.
Drivers need to recognise that the 'matchers' recommendations are intended to achieve maximum performance. It is the recommendation from the cell manufacturer that should be used.
Best Practice for use of NiMH cells.
1. Equalise cells before charging if they have been stored (with charge) for more than 2/3 days. If any of the cells in the pack show that they do not need to be equalised (i.e. the light does not show or goes out straight away) then remove the pack from the equaliser and charge for a short period (approx. 5 mins. should be adequate). Then carry out the equalising process.
2. Never exceed the manufacturers recommended fast charge rate. This should be 1C max., even if the manufacturer states higher. (C being rate of charge based on capacity of the cell, e.g. a 4200 mAh cell = 4.2 amps)
3. Disregard any charge rate recommendations by the 'matcher' if it is more than 1C.
4. Use a maximum Delta-Peak setting of 3mV per cell (6-cell pack = 3mV x 6 =0.018V).
5. Never repeak cells after main charge.
6. Use a temperature cut-out as an additional safety feature set at 42 deg. C max., located on the hottest cell (usually middle cell). If charging on a cold day then consider reducing this to around 35 deg. C.
7. Allow cells to fully cool to ambient temperature before further charges. Be aware the
centre of the cell cools slower than the outer casing. Do not put them in water to cool down; in an emergency cover the cells with a damp/wet cloth if you have to quickly cool them.
8. Store cells with some charge (30/50%).
BRCA Electric Board 16.11.07
UPDATE:
Updated news regarding NiMH 4200 cell faults.
The Intellect Battery Co. have now supplied the following cell Batch No's., which may contain cells that could explode when subjected to ‘race type’ conditions :-
ARAET, AZCWT, BNCWT, BNDST, BRAET, BZAWT.
We must stress that the Batch No's. detailed have been compiled only from returns by European customers to Intellect. There may be other batches that we have not yet been notified of. (So, do not assume that if a Batch No. is not detailed above, that it does not have any problem cells within it). Some EU drivers obtain cells directly from USA, etc. and it is possible that batches outside the EU could also be affected which have not been notified to us.
Intellect supply the same cell in 'Customer designed shrink'. Intellect has not confirmed if the same Batch Codes are used on these versions of cells. Most of the reports that have been received appear to be relating to cells in the Intellect shrink. Hopefully the above information will cover most of the problems.
BRCA Electric Board. 17.11.07
Sounds like they were concerned to me..
tosh..........ALL power sources pose a risk, its how you use em, would you fill your big car up with petrol and a fag in ur gob?
no body did sh1t when IB's were exploding,
Sit down Mark, gonna say something.... I AGREE WITH YOU.... really pisses me off this type of subject.
Yes, LiPo's can be dangerous, and it mostly comes down to abuse, very few failures can be put down to the actual cell failing in use... generally they have been charged on the incorrect profile, over-discharged or punctured in the car.
As for LiPo sacks, when someone comes up with a suitable sack, that contains the combustion and is tested AND stamped that it has passed said test, will I be happy with using one, as it is, LiPo Sacks is just a big can of worm, that is waiting to bight your arse!
mark christopher
30-11-2010, 11:08 PM
Sounds like they were concerned to me..
Concerned yes, doing jack sh1t still my comment stands
mark christopher
30-11-2010, 11:10 PM
Sit down Mark, gonna say something.... I AGREE WITH YOU.... really pisses me off this type of subject.
Yes, LiPo's can be dangerous, and it mostly comes down to abuse, very few failures can be put down to the actual cell failing in use... generally they have been charged on the incorrect profile, over-discharged or punctured in the
As for LiPo sacks, when someone comes up with a suitable sack, that contains the combustion and is tested AND stamped that it has passed said test, will I be happy with using one, as it is, LiPo Sacks is just a big can of worm, that is waiting to bight your arse!
Heck lol
I agree with ur other coments too
Shit Mark, hit Print Screen!!
David Church
01-12-2010, 07:21 AM
Heck lol
I agree with ur other coments too
Shit Mark, hit Print Screen!!
Feel the bromance:wub
Shhh!! I have slept since, I may change my mind DC :lol:
David Church
01-12-2010, 07:31 AM
Shhh!! I have slept since, I may change my mind DC :lol:
Haha nice!! Mark is special though:woot:
I have seen his bus, with the special licking windows!! :lol:
Only teasing Mark (never seen your bus!! :p)
David Church
01-12-2010, 07:37 AM
Mark's gonna love this, it's turning into a bashing session hehe
Big G
01-12-2010, 08:38 AM
it does highlight what happens if a lipo is punctured though and why we have to have hard case packs :)
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