As you can see 1 battery is clearly leaking, which I sure would be very harmful to my young son, or any child. I feel let down by this brand named company, and thought I was buying a safe quality product. Anyway I will not be buying these batteries again, and would advise not purchasing them until they sort out their safety problems.
Hopefully the future of batteries means that these sort of things never happens again, but I am not sure if this will be possible. It sounds like carbon nanotube batteries are the future, but they still contain acid, so how can they remove the risk? I am not sure, maybe the housing of the battery needs improving, also could improvements be made to the product that requires the batteries? I am not sure, but think it needs to be made a priority by the manufacturers to stop this sort of thing happening.