I too now find the smell of any kind of analog to be awful, but for some strange reason I am still attracted to crushed, empty cigarette packages lying in gutters - even after more than two years of vaping and no analogs. Oh well, I smoked analogs for over twenty years, so I suppose weird little things like that are understandable. For greater battery charging safety I ordered a Belkin Conserve Socket F7C009q Energy-Saving Outlet (which has a 1/2 hour, 3 hour and 6 hour power auto-cutoff timer switch on it), plus one Integy Large LiPO Guard Charging Bag INTC22532 (11.7 x 9 x 0.4 inches), and one Cables to Go 1.5 ft 1 to 4 Power Cord Splitter (to run from the Belkin outlet plug power shutoff timer into the LiPO bag for multiple battery charging). All of these items cost only about $5 to $10 a piece on Amazon, which wasn't a bad deal at all with free Super Saver Shipping (Amazon Prime). They are all also fairly compact and portable for use when traveling, at a hotel or wherever else. I will charge my ECHO batteries in that bag with the timer set to shutoff automatically after 3 hours (which is sufficient for the newer ECH 650mAh batteries and chargers). That will be in my kitchen, where everything is tile, both the counter top and floor, but I will also have the bag sitting in a small metal baking pan - for extra protection. I think that will be a pretty safe setup that will work well for charging 650mAh ECHO batteries.
I also bought another black 650mAh battery today, from a different supplier, as (interestingly enough) my other supplier is not selling this type of battery anymore - at least not for now, though that supplier still sells that model size's e-cigarette starter kits. I also got a few extra dual-coil cartomizers, which I like quite a bit - though they are not all that different in overall performance compared to the standard single-coil ECHO cartomizers. The single-coils are milder in throat hit & vapor production, but more e-juice flavor comes through.
Doing all that makes me feel quite a bit better, but I was (and still am) depressed about the damage to my bedroom carpet. Because of that, I used a Dremel tool and several different grinding tips (using scissors would have taken too long) to grind the hard burnt pieces of carpet down to fresh, cleaner carpet, then rewashed the whole area, finishing with several vacuum passes. I even used a bit of bleach to try and lighten some of the areas of carpet darkened by smoke. The results were far from perfect, but now the spot looks more like something of an old spilled drink stain, rather than something scorched with a torch. The area of damage is over a foot long, so it will sadly always be noticeable, and be a constant reminder of that terrible day when the battery blew up, but it doesn't look nearly as bad as it used to. I'll see what I can find out about maybe some other methods of getting the smoke stains out better. Lesson learned, eh?
Many people use much larger/longer PV batteries, at least up to 1300mAh, and even larger. I don't think it is practical for those that are charging batteries that size, that take several hours to recharge (overnight?), to be constantly monitoring the charging battery's status and condition. Even if one were to notice that a charging battery was seriously overheating, I for one don't think I would try to grab it and unplug it, as it might go off in my hand - which would be bad news in itself. Some kind of more extensive safety precautions are a must, like using the LiPO charging bags, power plug auto-cutoff timers, and whatever else helps assure greater safety. Having a fire extinguisher and fire blanket handy isn't a bad idea either, and you should probably have those around in your house anyway - especially near your kitchen.
My wife was a little disappointed that I didn't decide to quit using e-cigarettes entirely after this incident, but I am cutting back on their use, and my last order of e-liquids were all made in the next nicotine level down from what I usually order and use. I've only just recently switched over to using the ECHO from using m402 gear (which I had used fairly satisfactorily for quite a long time), and I find the throat hit increase from just using the higher performance ECHO to be great enough that I really don't need as much nicotine in my e-liquids anymore. So that is something at least, eh?