# Power Sources for Unmanned Aerial Vehicles: A State-of-the Art
## 2 Unmanned Aerial Vehicle (UAV)
### Hybrid Power Sources (Fuel Cell and Battery)
Lastly, Table 7 is dedicated to a thorough comparison of diverse power supply configurations, facilitating a nuanced understanding of the various options available for power delivery in different contexts. These tables, with their respective data and insights, play a pivotal role in elucidating key aspects of energy storage and power supply solutions. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Type**} & **Energy Density (Wh/kg)** & **Power Density (W/kg)** & **Cycle Life (Times)** & **Efficiency (\%)** \\ \hline Lead-acid battery & 30–40 & 200–300 & 300–400 & 75 \\ Ni-MH battery & 60–80 & 800–1500 & 1000 & 75 \\ Li-ion battery & 100–120 & 600–2000 & 1000 & 90 \\ Supercapacitor & 4–15 & 1000–100,000 & 100,000 & 85–98 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comparison between batteries and supercapacitors [48,95,96]. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Type** & **Advantages** & **Disadvantages** \\ \hline Lead-acid battery & Affordable, rapid discharging rate, and high recyclability. & Inadequate performance in low-temperature conditions. \\ \hline Ni-MH battery & High energy density, quick charging and discharging, and extended lifespan. & Pronounced self-discharge rate, the necessity for a cooling system, and higher manufacturing expenses. \\ \hline Li-ion battery & Elevated voltage, superior energy density, lightweight, durable cycle life, minimal self-discharge, absence of memory effect, and eco-friendly. & Reduced lifespan in high-temperature environments, susceptibility to overcharging and over-discharging, and stringent security requirements. \\ \hline Supercapacitor & Swift charging and discharging capabilities, absence of pollution, and remarkableity. \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Batteries and supercapacitor advantages and disadvantages. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Energy Sources** & **Architecture** & **Advantages** & **Limitations and Drawbacks** \\ \hline Thermal energy & Gas turbine engine & Impressive ratio of power to weight, coupled with extended duration of operation. & Extremely poor fuel efficiency and elevated noise levels. \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} Thermal energy \\ \end{tabular} } & \multirow{4}{*}{ICE} & Exceptionally high power and energy densities, extended endurance, and significant payload range. & Decreased efficiency, thermal and acoustic signatures, greenhouse gas emissions, and high fuel costs. \\ \hline \multirow{4}{*}{
\begin{tabular}{c} One \\ electrical \\ source \\ \end{tabular} } & \multirow{4}{*}{Battery} & Significant energy density and storage (rather than generation), resulting in a rapid response to power demand. & Limited power density, decreased endurance, and prolonged recharging time with the presence of a “memory effect” in certain battery types. To enhance autonomy, additional batteries need to be added, leading to increased weight and cost. \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \cline{1-1} \cline{2-4}  & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Comparison of power supply configurations.