I have been using a set of 3 3s LiPo packs for the last 4 years or so. They have been a boon enabling extended duration of video relay from sky to ground. I recharge them slowly, never at more than 1A. They have been part of my routine…importing photos in to Lightroom, make a cup of tea… put the first battery on charge, check camera state and I begin the image sift as the charger whirs away, its fan humming gently.
Today was different. I’d had the camera aloft for a good while and returned at dusk. I left the rig in its box and began the battery maintenance next morning. I’d already got the SD card out and had a first peep so the camera was not bolted into the rig, I plugged in the battery charging tail and settled down to check sharpness of the batch. There was a quiet hiss from the rig, I went to investigate, restarted the charger and went back to the digital negatives..seconds later there was a louder hiss..and white smoke seeping from the rig box…I whipped the box open…it burst into flame.. I grabbed the camera…opened the window and flung the whole thing out. I raced outside and pulled the rig and the 2 remaining LiPo packs out of the burning box and stamped out the fames..with the fire out I retuned indoors to find the floor had begun to burn from the residual heat from the offending battery which I’d dropped it on the floor as I disconnected the charger…there was no flame but a lot of smoke and the floorboards seemed to be melting at the fire site… by now the room had filled with thick white smoke and the smoke alarm had began its insistent bleat.
Once I ‘d got the smoke out of the house and silenced the alarm I thought about what had happened..and how lucky I was to get away with nothing more than a scorched rig and a nasty burn mark on my floor. This could have been very serious indeed.
I cleaned up the rig, most parts still worked..I only lost a switch, a servo, quite a bit of cabling and I’ll need to get new boxes for the video TX and OSD boards. The camera now has ‘cosmetic wear’ but survived in working order.
I’ll never trust a LiPo again and never leave it on the rig and never, never charge one unattended. I will put a stout pair of shoes on before charging them too!