I bet any YAPP would not do this !

[Sailingsaves]

Why did this battery charger's capacitor blow?

I am not having a go at the Far East company that we all know and love.

I buy lots from them as you will see at the end of the video.

But this morning something happened that made me think Bang is a good name.

Watch the video. I do not think I did anything wrong. Have been using this piece of equipment for a while.

I was testing the torches that I bought from them for longevity tests _ 4200mAh battery vs 3000mAh battery in their Cree T6 torches and comparing to my torch running on 4 AA NiMetalHydrides (I won by over an hour, but that is not the point).

I think it was scary. Thank goodness I don't let kids touch plugs and sockets that I do not trust. Let me know if you see something you think I did wrong, but I just turned it on ready to charge a battery as I have done before. The trailing socket that the charger was plugged into had a 5A fuse fitted and on the second attempt I replaced it with a 3A fuse. Luckily the only broken kit is the charger and not the house wiring or my nice anti-surge trailing socket.

I am now having to use my own cobbled together charger and get rid of the acrid fumes.

This is not a joke or an advert or promotion, but a warning to be careful (assuming I did nothing wrong and the bang was not my fault). I think at least one person on here bought a charger yesterday.

http://www.youtube.com/watch?v=Zmi3sh9P-Og&feature=youtu.be

 

[Sailingsaves]

Any one know why this would blow?

240V, 50Hz not my bag really.

 

[nigelmercier]

Any one know why this would blow? ...

Switch mode power supplies normally produce a Phapp! when plugged in, I wouldn't worry about it.

 

[Sailingsaves]

Switch mode power supplies normally produce a Phapp! when plugged in, I wouldn't worry about it.

I am more interested in learning what went wrong. The massive spark (6 inches out of socket was a little worrying though _ but not quite a brown trouser moment). The charger is kaput of course _ the capacitor has blown, circuit board burnt. Not a problem because it came free with the crumby batteries I bought (4200mAh my butt !) and I can charge the batteries with the charger I've made (via a 12VDC source !) _ give me DC any day.

Would be interested to know what / how it failed though after 3 weeks of use.

 

[elton]

With little to go on, I would first suspect a flashover/breakdown inside that big electrolytic. A circuit diagram would help with diagnosis, but instead of wasting my time, I'd just throw it in the bin and avoid buying similar again.

 

[Sailingsaves]

With little to go on, I would first suspect a flashover/breakdown inside that big electrolytic. A circuit diagram would help with diagnosis, but instead of wasting my time, I'd just throw it in the bin and avoid buying similar again.

Good advice, exactly what I have done.

I wrapped it in a bag because it stank so much, and binned it

I thought it may act as a warning to others, because yesterday one chap bought a torch without realising it needed these 'special' batteries and this charger and he was advised to buy the item that just burnt out.

Another chap said he had been using the same charger with his bicycle for years and thought I was being a little over cautious when I said I never trusted this charger and usually used it over a bed of sand and did not leave the room whilst it was on. In fact he said: "it's probably best if you don't knock things simply for being Chinese".

I wasn't knocking all things Chinese. But I would not recommend this charger. I was trying to be subtle and suggest people be careful with this particular charger and battery (being as Li ion need a little TLC).

Glad it happened to me and not someone else who may not have been as cautious as me and received a shock (maybe by sticking it in a socket that was already switch on [plus, there is a fair bit of bare metal exposed on this charger]).

 

[AngusMcDoon]

Fingers crossed that no YAPPs end up in flames! No explosions yet. I never do anything with mains though. I wouldn't trust myself with designing anything for charging lithium batteries either as they can cause lots of damage when they go wrong. I use components from Farnell, which although aren't the cheapest, seem to supply reliable stuff. I trust the decisions their buyers make.

 

[Sailingsaves]

Fingers crossed that no YAPPs end up in flames! No explosions yet. I never do anything with mains though. I wouldn't trust myself with designing anything for charging lithium batteries either as they can cause lots of damage when they go wrong. I use components from Farnell, which although aren't the cheapest, seem to supply reliable stuff. I trust the decisions their buyers make.

I would trust anything you made.

I have spent more with Farnell than I care to count.

Trouble is, the leaflets that arrive have such good bargains in them and sometimes only last a week or so.

My wife keeps telling me to stop spending, but I say to her "How can I experiment and make prototypes without kit?"

If I don't come up with the goods soon, I'll be in trouble.

 

[Norman_E]

I have what looks like the same charger, which came with a very nice torch and the same type of battery marked with an impossibly high capacity. I suspect that although the plug is marked 100-250 volts it is really intended for use in the USA on 110 volts. I'm thinking of replacing it with one of these http://www.ebay.co.uk/itm/321330810475?_trksid=p2055120.m1438.l2649&ssPageName=STRK:MEBIDX:IT
Any thoughts?

 

[LadyInBed]

Electronic components fail, if it's a trend, then it's a design fault.
When the mains fuse was replaced was that as in the diy book of fault finding "If the fuse blows, replace with a larger value and tune for smoke"

 

[William_H]

The switch mode power supplies are very common in LED light fittings and chargers. Especially in the light fittings they are made very small which gives very little margin for insulating gaps between conductors. The input capacitors on these power supplies are also miniaturised as far as possible making them more susceptible to failure on the mains voltage ie about 340v DC after rectification. DC volts equals peak of AC cycle. So yes they are rated 100 to 260v but as said probably get more use on 110VAC in USA.
I imagine your failure with smoke is an unfortunate not common falure. I have had failures with smaller power supplies in 240v LED lights. However I do think the charger should have been in an insulated box to say the least.
I have had a lot of fun with cheap stuff from China. Mostly OK. I did buy some 14500 Li-ion batteries that never arrived (refund given) possibly because airlines thought they were dangerous cargo. Boeing had just had a Li-ion battery fire. I charge my Li-ion batteries with as small current and am patient for a long charge ie 24hrs.
I have tested some Sub C NiMh batterie s andgenerally found them no where near the amp hour rating claimed but they are cheap. I haven't checked the Li-ion 14500.
I see you love Chines LED torches. I bought a claimed 1800lm Cree from banggood. It worked OK but did not seem especially bright compared to 300Lm claimed one I had. The multimode switch was anoying I prefer just on and off. not dim and strobe. Anyway this torch had a recharge socket. I had 3xAAA nimh in the little carrier. I connected my variable voltage charger to the recharge plug. I could not get any current into the batteries so in frustration cranked up the volts to over 12v There was a falsh of light and both the LEd and the electornics went to heaven in an instant. The electronic switch FET was overpowered and turned on giving cree led too much current. A little story of foolishness.
Anyway I am convinced this is the best torch ever especially for the price http://www.banggood.com/Wholesale-C...lashlight-Black(1+AA-Or-1+14500)-p-33588.html. I keep buying them for friends. Goes well on AA battery but brilliant on Li-ion. good luck olewill

 

[nigelmercier]

Anyway I am convinced this is the best torch ever especially for the price ...

I've got a couple of those at home, just ordered 6 of a slightly more conservative design, with twice the claimed lumens, to hang in the boat cabins and communal areas: http://bit.ly/1hnM0bP

 

[Neil_Y]

I used to work at IBM in the EAL lab life testing and investigating failed components, there was once a capacitor in CRT screens that would go Puff/bang with a cloud of acrid black smoke. We tried and tried to replicate it testing hundreds of capacitors but it was just the odd 1 in a 1000 that we think had a less than perfect insulating layer.

There are good and bad components but I would be tempted to inform trading standards for them to check if this item has a genuine CE marking to show it is made to a recognised standard. I'm sure there are cheap electrical items with poorer quality control getting through, but it is probably just one of the very small number of failures that are almost impossible to avoid in cheaper electronics.

 

[rhumlady]

If a switch mode PSU blows a fuse it goes in the bin as usually it goes bang with a replacement fuse. We are not allowed to open any switchers in work has it is too risky.

 

[single]

So which chargers and 18650 batteries are the safest brands to buy? No problems yet, but i am wary of the ebay Chinese ones.

 

[nigelmercier]

So which chargers and 18650 batteries are the safest brands to buy? No problems yet, but i am wary of the ebay Chinese ones.

TrustFire (unfortunate name) are quite popular, I've just ordered one. You won't like it though, it's from China.

Charger: http://bit.ly/1pymEwj
Note: this has 230V and 12V inputs, as well as a cover which allows the temperature measurement to be more accurate.

I also ordered batteries: http://bit.ly/1fWFu8e

At first I thought the Ah rating was a bit low, then I thought about it

 

[Norman_E]

I bought the charger that I posted the link to earlier. It arrived today and has just charged its first Li-ion batteries. It seems to be a well made piece of kit, with instructions written in good English.

 

[single]

I seem to have a mixture of different mAh 18650s now and also a few different chargers.Should the charger be matched to the mAh rating of the battery, or does it simply take longer the higher the mAh? (ie.same charger for all)