Just figured I'd tell you all a story to stress how important it is to be more careful than ever with the current battery-chemistry of choice -- LITHIUM POLYMER: it would be prudent to keep a fire extinguisher in close reach of these crazy high-power charging setups, or just near any place you choose to store and charge these little potential terrorists. I know it seems like it will never happen, but I can tell you firsthand that I've had my share of close-calls with lipo batteries.
I know some people who, and I am not joking, will only charge lipos outside of their homes and only when the batteries are sitting in a cinderblock "fort" so-to-speak. These batteries are a.k.a. the world's most dangerous batteries for a reason. Especially after they've had possible impact from a hard landing or crash its always a very wise idea to leave them away from combustible materials for observation for a period no shorter than 20 minutes before packing them into a place out-of-reach, like your trunk for instance, and driving off. This could lead to a very uncomfortable situation, though to be honest, the molten material might burn a hole through the trunk bottom and end up on the road so it might not turn into a total loss if you are in motion. j/k about the last part.
Seriously, I was inpatient at a rehabilitation hospital and in the middle of the night, broke the curfew and rules regarding not leaving the premises and took my trex 500 out for a spin. I was out of practice after having been in the hospital already for 3 months and kinda forgot my routine of inspecting the surrounding area for hard-to-see features that might end an otherwise successful flight. Go figure, there was an impossibly thin overhead phone line that I was destined to be tangled with. Long story-shortened: I had my co-conspirator (one of the three 24-hour caretakers/nurses who was helping me manage my new wheelchair) pick up the mangled remains as I am well-versed in repairing even the most severe incidents, and had him toss the parts into my backpack. We returned to the room and I threw the stuff into a corner of the room where my charger was located. Knowing the risks associated with lipos, and having seen a video once of a small 800mAh 2S pack being intentionally overcharged, I had at least the instinct to utilize a gift one of my hobby-buddies brought me when I first was hospitalized: a lipo-safe bag -- one word -- bull****. It ought to be called a lipo-safer-than-using-nothing bag. The next day, thankfully I was in my room due to a lawyer coming to have some papers signed by me, as I heard a familiar sound (that I learned in the video of the small lipo fire) of a hissing. I reacted quickly and yelled to my caretaker to "run that bag out to the sidewalk and toss it far away from anyone now!!" He looked puzzled and I insisted he do it immediately. I hadn't yet made the connection in my head that we were on the 3rd floor of the hospital (funny only because ultimately nobody was injured and no significant property loss was incurred, but keep in mind I was located in the special rehabilitation ward for paralyzed and really fu**-ed up patients), but my guy began his jog down the hallway toward the elevator. I guess "thankfully??" he didn't make it to the elevator (as there's no escaping once those doors shut) but the rest of the story I can tell not by seeing, but rather by hearing during and the aftermath, as I was stuck in my room. I suddenly hear a bunch of screaming and then, lo and behold, the fire alarm triggered and all the doors slammed shut. An evacuation of the entire wing of the hospital was announced initially, but luckily there was a staff member with quick reflexes who obtained a fire extinguisher and put out the flames quickly, and so both the evacuation as well as the ready-to-go sprinkler system were both halted, leaving just the rehab unit to evacuate (which is the biggest pain in the *** you can possibly conjure up. Immobile people needing to be moved due to the overwhelming smoke screen that two decently sized 6S lipos (3800mAh) caused. Upon regrouping with my caretaker, he tells me "thanks god you the battery into grey bag -- my life safe!" Further investigation revealed that he was fortunate that when black smoke began pouring from the bag, that he put the lipo-kinda-safe bag with the opening facing away from him and the nurses station that was only a couple meters away. Once he was certain that there was no way he was going to continue holding the bag, he placed it on the ground and then there was not just a fire, but by witnesses account there was more like a jet engine's torch-like flame that measured about 2-3 meters for a second or two, then regular fire. It's funny (not haha funny, just ironic I guess), in retrospect, especially because in the days leading up to the incident I made no secret of the fact that I had these materials in my room, as many of the staff doctors, nurses and cleaning crew saw me working on the heli and were admiring it, quite honestly. This was much to my advantage in explaining the situation to the fire chief who was taking my statement, since it relieved me of financial responsibility in replacing all of the fire/smoke sensors that existed on the floor that I was on. Apparently, the chemical composition of the resulting smoke cloud was of a nature that made any sensors exposed to it unreliable for future use. As for the lipo bag, the fire department returned the rubbish to me after verifying it was extinguished. I had intended to send it to the manufacturer, but as it turns out, I had many more pressing issues to address during that period of my life, so somehow it got tossed away and I can only recount my memory of what it looked like. Ultimately, the bag provided some degree of protection, but ended up burning completely through in some spots and did NOT contain the jetting flames in the direction of the opening of the bag during the combustion.
I am telling everyone this story for two reasons: because it is comical, but more importantly to spotlight the FACT that lipos have very much potential for serious damage. I was extremely lucky and thankful that nobody was hurt directly or as a result of this mishap. This also occurred nearly 15 hours AFTER the crash I had with the helicopter, not to mention that I did observe the battery, even though it was protected by a fiberglass canopy as well as the battery itself showed no signs of physical damage as far as I could tell, or I would've tossed it into some salt-water and tossed it way before it making it back into my bedroom!! Just goes to show the warnings plastered all over these batteries was not written just for fun. It could happen to you! I had hundreds of hours of experience with these battery chemistry, and was always cautious as I was lectured by my mentors while I was learning that "every year people either lose their homes or cars or even die as a result of being stupid with these batteries...they're unsafe...PERIOD".
