Europe and more specific, the Netherlands are drafting legislation (PGS37) that encompasses storage, transportation, and handling of lithium-ion batteries.
In short PGS37 entails that there will be put far-reaching measures in place to reduce the risks of potential lithium ion fire hazards. More information about the new regulations click here.
Due to for instance internal damages E-bike batteries can spontaneously combust, a so-called thermal runaway. This lithium ion fire can only be extinguished with a special extinguishing agent.
The consequences of a lithium ion fires can be grave and have enormous impact on the surroundings. Especially when the battery is inside at the moment of combustion.
When safety is concerned you could state that storing a lithium-ion batteries without using the Battery Control products is like driving a car at high speed without a safety belt on.