I have recognized there are some people out there that believe that LiPo bags are too expensive and questions whether the bags are worth the bucks. They want to find ways to create them by themselves. I would give a big NO NO to this. Why try to save money on safety?
LiPo safety first
In an earlier article, Get yourself a LiPo Safety bag NOW! I wrote about why to use them. There are many LiPo safety bags to choose from out there and most of them are in the range 5-25$. So let us face it, if we put that money in relation to how much a house costs or in the worst case, someone getting hurt I believe that we should always put safety first. Spend a few dollars into this part of the hobby, it can save a lot of money in the end.
Quality may vary
Of course, the quality between all the brands may vary. Ensure that your lipo safety bag has been tested with acceptable result for the kind of battery that you are using, e.g. not to buy one that only can handle a 2S 1000MAh LiPo when you intend to use 3S 2200MAh LiPos. However, look at the LiPo sack as a device that will buy you time to take actions if there is an accident. They might not all be able to contain the fire though they will minimize the damage. It is always better to use a LiPo bag than not to.
Although I have personally never experienced any LiPo accident I still use LiPo safety bags every time I charge my batteries. I also use them for storage of the LiPos.
Some creative persons have taken the safety a step further and created their own LiPo charge box with smoke detection installed etc. This
Just make a search on YouTube for lipo battery safety and you will find a lot of videos.