5. Future work

Again, 440 J is stored into a 6 V 3.2 AH battery in one cycle.

Experimental observation:

Percentage of error:

charge 0.5 V.

4. Conclusion

it takes 18.8 h to charge another 0.5 V.

18 Supercapacitors - Theoretical and Practical Solutions

in theoretical and experimental values.

Direct charging without converter:

Therefore, 69,120 J can be stored into a 6 V 3.2 AH battery in (69,120/440) or 157 cycles.

Therefore, average time required for battery charging = [(27 � 157)/60]h = 70.65 h.

Therefore, total estimated battery charging hour = [(8.1 � 5) + (18.8 � 2)]h = 78.1 h.

Percentage of Error, POE <sup>¼</sup> ð Þ <sup>j</sup>70:<sup>65</sup> � <sup>78</sup>:1<sup>j</sup>

Efficiency of Supercap � based Battery Charging Circuit <sup>¼</sup> ð Þ <sup>j</sup><sup>123</sup> � <sup>78</sup>:1<sup>j</sup>

It takes 8.1 h to charge 1 V of the battery [from the previous result section]. Moreover, after 5 V,

The voltage drops in boost converter and MOSFET switch are the main reasons for difference

The battery takes 15 h to charge 1 V from the turbine until 5 V. After 5 V, it takes 24.2 h to

As a conclusion to this research, the achievements are reviewed in terms of research objectives. This consequently facilitates the system, and results are to be analyzed in terms of the percentage and degree of the research objectives that were achieved. Three cases had been compared for performance analysis. "Case A" showed a battery of 6 V, 3.2 AH, being charged from 4.2 to 5 V through a DC/DC converter followed by a series of four Supercaps. "Case B" and "Case C" demonstrated the direct charging of the battery, where "Case B" was experimented with the converter and "Case C" was without converter. Investigation was carried for 3, 4 and 5 m/s wind speed. "Case C" was taken as a reference. For a wind speed of 5 m/s, the result showed an increase of 19% of the charging time for Case A while charging through the Supercap. It took only 8.1 h whereas direct charging without converter took 10 h. Supercap-based charging was also found to be 133% more efficient than direct battery charging with a converter. Keeping in mind, direct charging might not be the appropriate way of charging a device since fluctuation of wind

Therefore, average time required for battery charging = [(15 � 5) + (24.2 � 2)]h = 123 h

70:65

� 100% ¼ 10:54% (3)

� 100% ¼ 36% (4)

123

Note: one charging cycle of supercapacitor bank takes 27 min on average.

Conventional DC/DC boost converter is to be replaced with the efficient one, which is specifically designed to work with voltage as low as 2–3 V. This will help Supercap to discharge even more and will play a vital role while dealing with low wind. All these changes will improve the system and should make it capable of performing at 2 m/s. Since most of the electronic devices operate at 12 V, a second DC/DC converter may be placed to charge a 12 V battery from the current 6 V-led acid battery.

Laptop should be replaced with wireless system in the future. A real-time wireless monitoring interface could be made available. Embedded solutions providing wireless end point connectivity to devices like XBEE modules can be of use in cases like this.
