Problems with chart node (multiple lines)

I got no success with a chart, using multiple lines. Maybe some can help.
This is what I have:
picture 1
picture 2

var dataArray = [[]];
var seriesArray = []; 
var labelsArray = [""];

for (i=0; i< 5; i++) 
{
    var name = msg.payload[i].brand + " " + msg.payload[i].place + " " + msg.payload[i].street;
    var preis = parseFloat(msg.payload[i].diesel);
    var dateTime = Date.now();
    //var timestamp = Math.floor(dateTime / 1000);

    dataArray[0][i] = {"x":dateTime,"y":preis};
    seriesArray[i] = name;
    //node.send({payload: chart });
}

var chart = [{
    "series":seriesArray,
    "data":dataArray,
    "labels":labelsArray
}];


var chartMsg = {payload: chart};
return chartMsg;

Flow needs "Tankerkoenig" + API Id so may be its not so usefull for you:

[
    {
        "id": "97dfc7db.a3c4d",
        "type": "ui_chart",
        "z": "30b57812.5c8b38",
        "name": "Dieselpreise",
        "group": "107ce709.2e71e1",
        "order": 0,
        "width": "6",
        "height": "6",
        "label": "Diesel",
        "chartType": "line",
        "legend": "true",
        "xformat": "HH:mm:ss",
        "interpolate": "linear",
        "nodata": "Noch keine Daten vorhanden",
        "dot": true,
        "ymin": "1.00",
        "ymax": "2.00",
        "removeOlder": "72",
        "removeOlderPoints": "",
        "removeOlderUnit": "60",
        "cutout": 0,
        "useOneColor": false,
        "colors": [
            "#1f77b4",
            "#aec7e8",
            "#ff7f0e",
            "#2ca02c",
            "#98df8a",
            "#d62728",
            "#ff9896",
            "#9467bd",
            "#c5b0d5"
        ],
        "useOldStyle": false,
        "outputs": 1,
        "x": 1530,
        "y": 560,
        "wires": [
            []
        ]
    },
    {
        "id": "107ce709.2e71e1",
        "type": "ui_group",
        "z": "",
        "name": "wenzlaff.info",
        "tab": "7e68b62d.0b5fa",
        "disp": false,
        "width": "6",
        "collapse": false
    },
    {
        "id": "7e68b62d.0b5fa",
        "type": "ui_tab",
        "z": "",
        "name": "wenzlaff.info",
        "icon": "dashboard",
        "disabled": false,
        "hidden": false
    }
]

I am unsure whats wrong, since I see no big differences to the working version of @truglodite
The chart should show a line for every entry of seriesArray and add a new entries without deleding the old once.
Thanx for your help!

Your code will not output multiple "series".
The output should look like this (3 lines in this example).

In the example are 3 lines / values:

"data": [
    [{ "x": 1504029632890, "y": 5 },
     { "x": 1504029636001, "y": 4 },
     { "x": 1504029638656, "y": 2 }
    ],
    ....

I ve one but the same structure (If I didn´t miss a thing)
With one line I expected to set only one point BUT multiple lines. - for every entry in "series" one.
But see what I got: click
There is only one line for first iteration. - Shouldn´t it be like I descriped ?

I would like to draw more values to the chart when I request the values next time without deleding the existing ones. - I guess that is another problem I have no solution for atm.

This is my solution for the problem(s):

Function node:

var sqr = 0.0;
var len = msg.payload.length;
for (i=0; i< len; i++) 
{
    var name = msg.payload[i].brand + " " + msg.payload[i].place + " " + msg.payload[i].street;
    var preis = parseFloat(msg.payload[i].diesel.toFixed(2));
    node.send({topic:msg.payload[i].brand + " / " + msg.payload[i].place,payload: preis.toFixed(2) });
    sqr+=preis;
}
node.send({topic:"DURCHSCHNITT",payload: (sqr/len).toFixed(2) });
return null;

flow could remain like posted.