Creating new captions and "caption-counters"

It would be advisable to create a separate float that contains your charts. That allows you to have a handle into changing things in the future. For example, if you decide to reformat them differently, or perhaps make them the same.

The float package can easily create new floats:

\documentclass{article}

\usepackage{float}

\newfloat{chart}{htbp}{loc}
\floatname{chart}{Chart}
\newcommand{\listofcharts}{\listof{chart}{List of Charts}}

\begin{document}

\listoftables
\listofcharts

\section{A section}

This is a \verb|table|:

\begin{table}[h]
  \centering\caption{Example}
\end{table}

And this is a \verb|chart|:

\begin{chart}[h]
  \centering\caption{Example}
\end{chart}

\end{document}

A comparable setup using newfloat (compatible with caption) would be

\usepackage{newfloat}

\DeclareFloatingEnvironment[
  fileext   = loc,
  listname  = List of Charts,
  name      = Chart,
  placement = htbp,
]{chart}

You can use the newfloat package that cooperates out of the box with babel and caption.

\documentclass{article}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage[brazil]{babel}

\usepackage{caption,newfloat}

\DeclareFloatingEnvironment[
  fileext=loc,
  listname=Chart, % English name
  name=List of Charts, % English name
  placement=tbp,
]{chart}

\addto\captionsbrazil{% provide translations for Portuguese
  \renewcommand{\chartname}{Gr\'afico}%
  \renewcommand{\listchartname}{Lista de Gr\'aficos}%
}

\begin{document}

\listoftables
\listofcharts

\section{A section}

\begin{table}[h]
    \centering
    \caption{Example}

    \begin{tabular}{l r}
        \hline
        City        &   Habitants   \\
        \hline
        City A      &   2000000 \\
        City B      &   4000000 \\
        City C      &   500000  \\
        \hline
    \end{tabular}
\end{table}

And this is a "chart": %might want to change the word

    \begin{chart}[h]
        \centering
        \caption{Example}

        \begin{tabular}{|c c|}
            \hline
            City        &   Habitants   \\
            \hline
            City A      &   2000000 \\
            \hline
            City B      &   4000000 \\
            \hline
            City C      &   500000  \\
            \hline
        \end{tabular}
    \end{chart}

\end{document}