Because only the rich can afford cheap batteries..... A good quality deep cycle lead acid battery will cost between $50 and $200 and, if properly maintained, will give you at least 150 deep discharge cycles.
What is the boiling point of oxygen? a. 100 degrees C c. -57 degrees C b. 8 degrees C d. -183 degrees C.
Extreme injury and death can result all too quickly. In the case of oxygen, you also have another danger. If the liquid oxygen is converting back into a gas, then you will have too much oxygen around you. Oxygen is what is needed to keep a fire burning. So with extra oxygen around, substances that are normally almost non-flammable can suddenly be very flammable!