I'm not a fireman, but wouldn't a wet towel do the job? I would think a thick towel doused in water should do the trick. you can keep pouring water on the towel to keep it soaked till things quiet down. This would keep the temp from rising higher and at the same time minimize the spread of fumes. Of course, unplugging the laptop at the first sign of smoke is helpful too. On a plane, I suggest running to the toilet with the laptop at the first sign of smoke. Then do the towel bit. With millions of laptops in use everyday, the chances this would happen to you is very slim. Li-ion batteries have a safety fuse in them to prevent such accidents from happening. My advice? Stay away from cheap unbranded replacements. The money saved from buying an unbranded one other than a more expensive original battery pack wouldn't nearly cover the price of your laptop if it does explode. At least with the original, the company would reimburse your laptop.