Bike light charger fire

[Deleted member 26818]

I thought this was ultimately the homeowners responsibility to inform LABC?

Yep.​tep

 

[Lucien Nunes]

I don't expect the two events are related. There's nothing you can do at the CU to 'alter' how the laptop charger works - either it gets 230V between L&N in which case it charges the laptop, or it doesn't. Polarity doesn't matter. Inside the laptop, the 20V DC - or whatever the charger produces - is converted to various other voltages including 5V for the USB output. So even a malfunctioning laptop charger would, as you say, normally fry the laptop innards first, before affecting anything plugged into the USB ports.

The only really obscure and nasty scenario I can invent to connect the two is that the final circuit that the charger was plugged into had its CPC connected to line at the CU, making the laptop chassis (and probably everything else in the room) live. Then somehow the output side of the bike lamp charger contacted real earth potential and the fault current passed through the laptop charger and laptop DC ground without visible harm but fried the final link in the chain.
Other than this almost-inconceivable occurrence, it's just coincidence.

It's hard to get enough power out of a USB port to do real damage, even at 2A it's 10W, half a soldering iron's worth of heat. But if something on the output side shorts, the lamp battery might discharge back into the short and even a small LiIon can pack a punch and burn things out sharpish. Also, some of these products are not made of properly self-extinguishing plastics so once something gets too hot, the whole casing bursts into flame.

I would be interested to see a close-up of the PCB from inside the charger. I see a lot of blown-up power electronics and can often reconstruct the chain of events.

 

[Marvo]

These switch mode chargers are downright dangerous, I've personally had two that have gone molten and I know someone that lost the contents of his garage because of one that combusted. I've now set up a single charging shelf in our house with a large multiplug which is on a 24 hr timer so it switches off at 11pm and back on at 7am, that way there won't be a fire when there's nobody around to deal with it.

I agree with Lucien, it's highly unlikely the charger fire was related to anything happening in the CU.

 

[trev]

I thought this was ultimately the homeowners responsibility to inform LABC?

Yes it is but this clown might not know that.

 

[driverman]

These charges are extremely dangerous, especially cheap imported ones that swamp this country. Saw one on TV other day, whereby a visitor to a friends house plugged in an e-cigarette charger. It ignited and burnt all the kitchen out! There are numerous reports of these things going wrong.

 

[dens333]

I suspect it was foul play from the green skeleton!

 

[VoltzElectrical]

These charges are extremely dangerous, especially cheap imported ones that swamp this country. Saw one on TV other day, whereby a visitor to a friends house plugged in an e-cigarette charger. It ignited and burnt all the kitchen out! There are numerous reports of these things going wrong.

I saw one on one of those consumer programs like watchdog, where one woman bought a charger from a market whilst on holiday, for her grandson's device and it electrocuted him.

 

[driverman]

I saw one on one of those consumer programs like watchdog, where one woman bought a charger from a market whilst on holiday, for her grandson's device and it electrocuted him.

And more than likely no one prosecuted.

 

[mike the bull]

Did you check the ends of bike light charger. I know had smart phone chargers where the ends are loose or broken in the cord ends