Oops, my fault. Another 18650

[90VG]

I bought a nice work lamp with 3x18650 batts in it, China no-name brand. I plugged it in to charge, and it was in a location I can't see easily. I had some late night equipment failures at the house (cooler) and was pretty tired, off to sleep, batteries still charging.

BOOM!

It woke me and the dog up, the whole top floor stunk horribly and there was some smoke in air. I went into my office and a paper plate the dog pulled out of the trash was on fire, battery melted into the rug beneath it (still smoldering).

Burnt stuff was scattered about 15ft from where the battery landed.

All is fine. Damage, cheap rug from a garage sale $10. Lesson, well, we all know what I did wrong.

Pics:

 

[jandrew]

Unfortunate --- Glad the damage was minimal.

 

[Anise]

I swear I will NEVER leave a battery charging overnight or go off somewhere while one's charging!! Thank you for the reminder. You were lucky.

 

[90VG]

The worst part was the smell, way nastier than the most devilish fart.

 

[90VG]

I do electronics stuff, so I'll have a forensic video about the charging circuit, the event, batteries, etc. Full details later on, maybe tomorrow.

 

[Fidola13]

I bought a nice work lamp with 3x18650 batts in it, China no-name brand. I plugged it in to charge, and it was in a location I can't see easily. I had some late night equipment failures at the house (cooler) and was pretty tired, off to sleep, batteries still charging.

BOOM!

It woke me and the dog up, the whole top floor stunk horribly and there was some smoke in air. I went into my office and a paper plate the dog pulled out of the trash was on fire, battery melted into the rug beneath it (still smoldering).

Burnt stuff was scattered about 15ft from where the battery landed.

All is fine. Damage, cheap rug from a garage sale $10. Lesson, well, we all know what I did wrong.

Pics:

I’m glad you’re ok and I hope have a better understand about battery safety esp unsupervised charging.

 

[r77r7r]

The dog put a plate under the battery to protect the carpet?

 

[Fidola13]

Why is it on a paper plate?

 

[90VG]

The dog dug the paper plate out of the trash over the night. That's where the battery landed. I have to pick stuff up every morning from him. Little bugger waits for me to go to sleep then starts his quest for goodies.

 

[Rossum]

I bought a nice work lamp with 3x18650 batts in it, China no-name brand.

Sounds like it's unclear whether the source of the problem was the charging circuit, or whether one of those batteries was simply defective?

Personally, I won't use no-name (or any re-wrap brand) Chinese 18650s in anything, not even a flashlight. They've gotten better at making cells with decent performance, but manufacturing flaws can cause spectacular failures like this. The big boys (Sony/Murata, LG, Samsung, Panasonic) have really good QA/QC practices and that keep flawed cells very low (supposedly fewer than one in a million). I really doubt that the generic Chinese manufacturers come anywhere close to that.

 

[90VG]

One of the batteries in the enclosure, you can see the char marks on it from the one that popped. 2 batteries appears to have survived, although chemically dead (Reads 2 volts then approaches zero after 10 secs). They are going in the burn barrel.

 

[90VG]

For those curious, this is the logic chip:

Does that say Hot Chip? Well, it's named properly.

 

[Eskie]

The board is in pretty good shape considering. No idea what those batteries are but in truth doesn't matter.

 

[90VG]

Well, my verdict is in. It's a badly designed circuit, with the wrong power supply.

It's designed for 5 Volts in, came with 2 12 volt chargers. 3x18650 in parallel. So it was over voltage. The light still works though. I will cut off the charging leads and charge it in the vape charger.

I don't have a decent schematic/datasheet for that chip yet, but I'll get one soon.

 

[90VG]

Vin pin, epoxy/plastic whatever melted slightly.

 

[90VG]

The whole board, oriented in chip direction. V+ V- go to Power Source, K goes to the switch (pulse to ground), Black is ground, battery I haven't traced out yet. There's all the details. It's not often that it happens to someone on E-Cig-Forum, so all information that I have is available.

 

[somdcomputerguy]

I'm glad this didn't turn out worse, @90VG. Carpets, no matter how inexpensive or expensive can be replaced a whole lot easier than lives or skin..

 

[90VG]

I don't really care about the rug. Just glad it's all fine. Notice you don't see me talking about suing anyone? It was my fault not inspecting the whole thing first before use. It came in the original box, with a 12V car charger (lol). Imagine that going off while driving.

Anyways, it will serve its function fine as a work light, I'll just swap in vape batteries for the ones it came with. The charging portion of the light is disabled now.

Anyways, if you found a work light, LED, 10 watt, at a garage sale with 3 batteries and a charger wouldn't you pick it up for $8.00 USD?

 

[jim_87]

That paper plate may have helped. If it wasn't there, it probably would have went through the carpet onto the wood floor, could have been a house fire. Seems your dog did a good thing digging in the trash this time.

 

[90VG]

Doggo is really old, so I don't correct him on little things like pulling out paper plates. I don't think it would help any either, he's gonna do it when the snoring starts.