Something wrong with my arduino code? Lost sync with device, restarting...

edit

Hi guys. I'm using an arduino mega with the rosserial stack. I tried to write a code to read the voltage of a LI-FE accumulator. Rosserial should show me the measured voltage in a terminal. The last step of my project was to sum two characters, so that i can connect more accumulators and see which accumulator has which voltage. The crazy thing about that is that it worked as I used this order: "measured voltage, text" but when I change the order to "text, measured voltage" my terminal says: lost sync with device... after i typed "rosrun rosserial_python serial_node.py /dev/ttyACM0" and "rostopic echo chatter".

Here is the code that worked:

int spgn1 = A5;
int ledpin = 13;
int Spannung1=0;
double Spgn1=0.0;

#include <ros.h>
#include <std_msgs/String.h>

ros::NodeHandle  nh;

std_msgs::String str_msg;
ros::Publisher chatter("chatter", &str_msg);


char Text[17]=" Volt an Zelle 1";
char Zelle1[32]="";



void setup() {
  // put your setup code here, to run once:
  pinMode(ledpin, OUTPUT);
  nh.initNode();
  nh.advertise(chatter);

}

void loop() {

  Spannung1 = analogRead(spgn1);
  Spgn1 = ((0.005*Spannung1)-0.0703);
  dtostrf(Spgn1,10,2,Zelle1);
  strcat(Zelle1,Text);
  str_msg.data = Zelle1;
  chatter.publish( &str_msg );
  nh.spinOnce();
  delay(5000);

}



And here is the code that did not work:


int spgn1 = A5;
int ledpin = 13;
int Spannung1=0;
double Spgn1=0.0;

#include <ros.h>
#include <std_msgs/String.h>

ros::NodeHandle  nh;

std_msgs::String str_msg;
ros::Publisher chatter("chatter", &str_msg);


char Text[]="Zelle 1: ";
char Zelle1[32]="";



void setup() {
  // put your setup code here, to run once:
  pinMode(ledpin, OUTPUT);
  nh.initNode();
  nh.advertise(chatter);

}

void loop() {

  Spannung1 = analogRead(spgn1);
  Spgn1 = ((0.005*Spannung1)-0.0703);
  dtostrf(Spgn1,10,2,Zelle1);
  strcat(Text,Zelle1);
  str_msg.data = Text;
  chatter.publish( &str_msg );
  nh.spinOnce();
  delay(5000);


}

I hope you could understand what my problem is and i also hope that you can help me with that.

Thank you