Yes it does Eddie, and we have one member at least who swears he will never charge indoors again. In Germany one woman had her house burnt down by a bike battery which caught fire.
That's the downside, but it's not all bad news. Most of the troubles came from the older Li-ion Cobalt type, and they were superceded by Li-ion manganese which are very much safer. Another type, NiMh, can under certain circumstances generate huge heat and melt down, but NiMh chargers these days generally have three cutout methods to ensure the charge stops before there's any danger of that.
In conclusion though, I would never charge a battery indoors when I'm out, but am happy to do it when I'm indoors and near enough to the battery to know if something starts going wrong.
If trouble ever occurs, pick up the battery with gloved or wrapped hands as they can get seriously hot, then either throw it into a garden and stay well clear or put it into a bucket of cold water to cool and finish it's collapse.
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