Before last night the most serious incidents in the shed have been limited to the odd scalpel cut, some decal solution in the eye, and the time I super-glued my elbow to the cutting mat, and stood up without realising. (That was just a wound to my pride to be frank!) Last night’s incident is an order of magnitude more serious.
I’m sure everybody has heard of the potential dangers of LiPo batteries, and their combustibility. And I’m sure most people, like me, have thought them over exaggerated scare-mongering. Last night I found out just how true the stories are and how dangerous one of these things can be. I was just starting to think of installing the electrics in a radio controlled glider I’m building, and got to trying out the batteries and charger I’d bought back in the summer. The battery had been on charge for about an hour when I decided to call it a night and go to bed. I turned to check the display on the charger and saw the battery looking like this:
It really should be a neatly packaged ‘obloid’ and not swollen and ‘bursty’. It was also hissing quietly and giving off puffs of vapour. I thought I’d take a quick video to send of to the vendor to get a replacement when the hissing got much worse.
It was obvious it needed getting out of the shed quickly so I stopped filming and put my phone down on the bench, when the battery gave out a huge jet of vapour from the bottom left in the video, which immediately turned to a jet of flame, burning my left arm as I tried to open the door. Luckily I’d picked it up by the cables, or I’d still be in hospital! The flames spread to the rest of the battery with a loud ‘whoomph’ before I managed to get the door open and throw it out.
Here it is burning a hole in my lawn.
And what was left this morning
In the seconds before I got it out of the shed it spewed red hot ‘soot’ – hot enough to burn in to the back of my phone case and ruin it. I dread to think what would have happened had I not noticed it was swollen when I did, as I was seconds from shutting up to go to bed, while the battery was seconds away from exploding. I’d have lost the shed and everything in it, no doubt about it. And that would be as nothing to it happening in the house. This is the closest I’ve come to a fire like this, and it’s very disconcerting to imagine the consequences of a change in timing.
If you have a charger and battery like this then do what I’ve just done and bin it, even if you’ve used it umpteen times and it’s been OK. Don’t risk it. I consider myself very lucky that this has been limited to a burn on the arm and no damage to my shed.
Anyway, I’ll be buying my replacement batteries and charger from a reputable UK vendor, not cheap off eBay. I’ve also just ordered two fire extinguishers, one for the shed and one for the house. This incident has made me think seriously, for the first time, about how I’d deal with a small fire in the house. Obviously ‘get out’ is the solution, but an extinguisher in the house might buy enough time to stop further damage.