Flow of current in a circuit

Question

I am trying to create a circuit with resistors and voltage sources. I need to have each resistor labeled with their resistance (above) and the unknown current (below) flowing through the resistor. I manually added the unknown currents using nodes. Finally, I need to have arrows showing the flow of current through the circuit placed at each of the nodes. In my MWE (taken from an earlier question, circuitikz label malfunction), given below, there are four nodes (junctions). How do I get those arrows using what is provided by circuitikz? I need three arrows at each of the nodes indicating the flow of current (either into or out of).

\documentclass{article}
\usepackage[american,siunitx]{circuitikz}
\begin{document}
\begin{circuitikz}[x=1.5cm,y=1.2cm]
    \draw (0,0) to[battery, l=12<\volt>] (0,2) -- (0,3.5)
                to[R,l=4<\ohm>] (4,3.5) -- (4,2)
          (0,0) -- (4,0) to[battery, l=24<\volt>,i>] (4,2)
          (0,2) to[R, l=2<\ohm>, *-*] (2,2)
                to[R, l=3<\ohm>, -*] (4,2)
          (2,0) to[R, l=2.5<\ohm>, *-] (2,2);
    \draw (1,1.6) node { $I_2$};      
    \draw (3,1.6) node { $I_3$};
    \draw (2.3,1.0) node { $I_4$};
    \draw (2,3.1) node { $I_1$};
\end{circuitikz}
\end{document}

I would like to avoid having the add the arrows manually. There are several questions regarding circuits, however, I've been unsuccessful in finding an answer to my question. If this is a duplicate I apologize.

Answer 1

To add arrows representing the current flowing through resistors you just have to follow the package guide in which there are some examples about this problem in section 4.2 Currents.

Thus, the example becomes:

\documentclass{article}
\usepackage[american,siunitx]{circuitikz}
\begin{document}
\begin{circuitikz}[x=1.5cm,y=1.2cm]
    \draw (0,0) to[battery, l=12<\volt>] (0,2) -- (0,3.5)
                to[R,l=4<\ohm>,i_=$I_1$] (4,3.5) -- (4,2)
          (0,0) -- (4,0) to[battery, l=24<\volt>,i>] (4,2)
          (0,2) to[R, l=2<\ohm>, *-*,i_=$I_2$] (2,2)
                to[R, l=3<\ohm>, -*,i<_=$I_3$] (4,2)
          (2,0) to[R, l=2.5<\ohm>, *-,i<_=$I_4$] (2,2);
\end{circuitikz}
\end{document}

The result:

P.S. The current direction might be wrong ;)

Answer 2

For the arrows, you can use three small 'short' segments to put the arrows on the nodes:

\begin{circuitikz}
\draw
(0,4) 
to [R, l=R1] (2,4)
to [short, -*, i=$I_1$]  (3,4)
to [short, i<=$I_2$]  (4,4)
to [R, l=R2] (6,4)
(3,4) to [short, i=$I_3$]  (3,3)
to [R, l=R3] (3,1)
;
\end{circuitikz}

I'm not sure I understood the label problem. I use a lx label, from this thread:

Set label name on two lines in CircuiTikZ

Cheers!