Effect of Time Factor on the Battery Voltage State of Charge from Foot Beats Piezoelectric System

Aim: The study examined the effect of time on amount of voltage generated in a foot beat electricity generating system stored in a battery.

Study Design: A system made of piezoelectric materials was designed such that the foot beats of dancers on a platform would cause a mechanical deformation that would lead to conversion of mechanical energy due to pressure from the foot beats to electrical energy; and can be stored in a rechargeable lead acid battery for future use.

Place and Duration of Study: Awka Anambra State, Nigeria, between November 2018 and April 2020.

Methodology: A sheet of plywood measuring 300 mm x 300 mm x 3 mm thick was placed on a hard wooden board of 300 mm x 300 mm x 25 mm thick where twelve piezoelectric sensors were connected in series with foam spring inserted as separators and to aid in returning after deformation. As the dancers step on the platform, multimeter was used to take the voltage and current readings, while Lead acid rechargeable battery could be connected at the output point to store energy generated in the system and or Light Emitting Diodes (LED) and Universal Serial Bus (USB) outputs. A stop clock was also used to take the time.

Results: The study revealed that it would require 901 seconds for a 50kg dancer to increase a unit voltage state of charge in a battery. It also found that it would require 749 seconds for a 60 kg dancer; and 595 seconds for an 80kg dancer respectively to increase the same 1-unit voltage state of charge in a battery. The study showed that the voltage in the battery would continue to increase until the battery is fully charged at which point it is expected that there would no longer be any increase in charge in the battery irrespective of increase in the number of foot beats or time.

Conclusion: The result implies that the charge in battery caused by pressure from the foot beats is subject to the maximum voltage capacity of the battery in the system. Likewise, the amount of time and number of foot beats required to add a unit voltage state of charge in a battery in the system is subject to the applied pressure from the foot beats. In view of this, the study craves for popularisation of this technology through large scale research supported by government, corporate organisations or international organisations and institutions that will support new products development in the building and construction industry as it is the case in India and other developed countries.