@TimO @boozz
Finally there I did, the problem was due by the resistances; I bought the new resistors
2M Ohm and 470k Ohm and now works correctly.

Thank you all for your support and for your patience

(Now I have a little more knowledge on electronics )

Mattia

@TimO
Sorry, but Whatsapp is AREF? Is the Pin thai I use to measure the battery voltage (A0) ? Bcause on Google i find some Arduino Board with AREF pin but my Arduino mini pro has not that pin.

Thanks
Mattia

I have rebuild the dividers with R1 1M ohm and R2 220k ohm, i have try with pin A1 and A0 and have strange value

990
Battery Voltage: 5.59 V
Battery percent: 99 %

1023
Battery Voltage: 5.78 V
Battery percent: 102 %

First read is correct, but after this all other value have value 1023, if use multimeter on R1 and R2 have a value of 0,93 on touch point have 0,93 and on the Pin A0 or A1 have the same value.
It is possible that Arduino read the wrong value ?

I have change R1 to 2M and R2 470k , I think to have some problem with resistors, tomorrow will buy new resistors and try again from scratch.

Thanks for your help
Mattia

@boozz
Many Thanks, now I understand but I still have doubts, in the skecth i have change this
float batteryV = sensorValue * 0.003363075;
in
float batteryV = sensorValue * 0.00575035;

because if I understand it ((1e6+470e3)/470e3)*1.1 = Vmax = 3.44 Volts
in my case is ((1+0,23)/0,23)*1,1 = 5,88 and after 5,88/1023 = 0,0057478
Now, however with new battery the output is

99
Battery Voltage: 0.57 V
Battery percent: 9 %

The code i used is
// get the battery Voltage
int sensorValue = analogRead(BATTERY_SENSE_PIN);
Serial.println(sensorValue);
// 1M, 470K divider across battery and using internal ADC ref of 1.1V
// Sense point is bypassed with 0.1 uF cap to reduce noise at that point
// ((1e6+470e3)/470e3)*1.1 = Vmax = 3.44 Volts
// 3.44/1023 = Volts per bit = 0.003363075
float batteryV = sensorValue * 0.00575035;
int batteryPcnt = sensorValue / 10;

Thanks
Mattia

Good morning,
Congratulations for this fantastic project ; are my first steps with Arduino and I have a litle problem with battery monitor on Arduino Pro Mini 5V, I use the sketch and instructions find in this page http://www.mysensors.org/build/battery , but the value read in pin A0 is always 1023, i have try othe analog pin with the same result
In touch point however the value is 1,4 /1,5 measured with digital multimeter, in pin a0 the value is the same.
The sensor is powered from 4 AA battery 1,5V .
I do not understand where wrong.

Sorry for the English is not perfect

Thanks
Mattia

Hi Michele, have you try to "reboot" the sensore Node, because only when Sensore Node "boot" he send the presentation information to the Controller (Jeedom).
Normally the sensore is added in automatic.
Check the log in Main->management->logs and select mySensors from dropdown menù on the top let, in this log you can see the communication between Gateway and node.