Recharging accumulators of electric drive carriages involves a risk of fire-explosion. In fact, when recharging, the delivery of electric current determines an electrolyse process where hydrogen develops. Also, strong acids contained in the battery evaporate in part. Consequently, the room may be saturated which can form an explosive mix.
Hydrogen (H2): it develops during the recharging process of accumulators.
H2: at elementary state, atmospheric pressure and room temperature it is a colourless, odourless, highly flammable gas. Hydrogen is the lightest, most abundant element in the whole universe