manual/plugins/batterybenchmark.tex

   1 \subsection{Battery Benchmark}
   2 The Battery Benchmark Plugin enables you to test your battery's performance,
   3 while making normal use of your \dap. Once loaded it will run in the
   4 background (TSR plugin), reading various info about your battery while you use
   5 it. Once you finish your session you can find the benchmark output data in a
   6 file on your \dap\ \fname{/battery\_bench.txt}.
   7 Please submit your results to the Rockbox wiki.
   8 \wikilink{BatteryRuntime}
   9
  10 \subsubsection{How it works}
  11 After you load the plug-in the operation of your \dap\ continues as normal.
  12 You can do whatever you could do before loading the plugin except loading
  13 another plugin. If you happen to load a plugin while benchmarking, a splash
  14 screen will inform you about the termination of the benchmark.
  15 While you operate it will log various battery related information every time
  16 the disk is activated by external causes, (buffer refill, open directory,
  17 USB mode) or an hour passes without updating the log file.\\
  18 The plugin will continue to log info until:
  19
  20 \begin{itemize}
  21 \item Another plugin is loaded.
  22 \item The \dap\ is shut down.
  23 \item The battery is empty.
  24 \end{itemize}
  25 Between disk activity (or an hour), it will log info in memory (every
  26 measurement is captured when the voltage changes). If there are too many
  27 measurements older entries will be deleted and the log file will inform the
  28 user about the interval where entries were lost. Benchmarks can be resumed if
  29 you accidentally load a plugin, or turn off your \dap, as long as the log
  30 file \fname{/battery\_bench.txt} is not deleted.
  31
  32 \subsubsection{Information explained}
  33 On the top of the file you will see various info on how to use the plugin.
  34 \begin{description}
  35 \item[Time] This column reports the total time of operation of the \dap. It is
  36 not the time that you started the plug-in. If you have your player on for 5
  37 minutes and then start the plugin, it will start measuring from 5 minutes.
  38 \item[Seconds] As time, it shows time passed in seconds. Nothing special, it is
  39 there because it is free and maybe someone might want to make graphs with
  40 seconds.
  41 \item[Level] The percent level of the battery estimated by Rockbox. This is an
  42 estimation and not an accurate result. Using the real percentage (current
  43 battery voltage / top battery voltage) * 100) we can calculate the difference
  44 between the estimation. Goal of this column is to make the estimation algorithm
  45 of Rockbox more accurate.
  46 \item[Time Left] It shows the estimated (by Rockbox) remaining time until
  47 shutdown. Again, as with Level(above), this column can be used to see
  48 differences between real time left and estimated time left. This could help
  49 make time left more accurate.
  50 \item[Voltage] The battery voltage, the moment the measurement was captured.
  51 Measurements are captured when this number changes while benchmarking.
  52 This column can be used to give quite interesting graphs in a spreadsheet
  53 program. (Excel, Calc, e.t.c)
  54 \item[M/DA] (Measurements per Disk Activity) The number of measurements stored
  55 temporarily in memory, before written on the log file. This can give you an
  56 idea of how many voltage changes there are between disk activity (or one hour).
  57 \item[C] Stands for Charger. An "A" in that column shows if there was the power
  58 adapter attached to the unit, at the time of the measurement.
  59 \item[S] The "S" column shows the state of the device (Charging, or not). The
  60 "C" indicated that the unit was charging when the measurement was captured.
  61 \item[U] USB powered. Only for targets that support this. A "U" will indicate
  62 if the unit was using the USB port for powering.
  63 \end{description}
  64
  65 \subsubsection{Making graphs}
  66 While you can tell how long your battery lasted, with a single look at the last
  67 line of the battery log (\fname{/battery\_bench.txt}), the most useful purpose of
  68 Battery Benchmark is to make graphs using a spreadsheet program like Excel or
  69 Calc. The battery log (\fname{/battery\_bench.txt}) is in CSV format (comma separated)
  70 so you can quite easily import it to a spreadsheet program.