@AWI: I am down to 1,3 µA 
my code:
//#define MY_DEBUG
#define MY_RADIO_NRF24
#define MY_NODE_ID 66
#define MY_PARENT_NODE_ID 0
#define MY_PARENT_NODE_IS_STATIC
#include <MySensors.h>
#include "Vcc.h"
#define SKETCH_NAME "MySlim2aaBatteryNode"
#define PRIMARY_CHILD_ID 3
#define PRIMARY_BUTTON_PIN 3
MyMessage msg(PRIMARY_CHILD_ID, V_TRIPPED);
const float VccMin = 1.7; // Minimum expected Vcc level, in Volts.
const float VccMax = 3.3; // Maximum expected Vcc level, in Volts.
const float VccCorrection = 3.496 / 3.572; // Measured Vcc by multimeter divided by reported Vcc
const int32_t report_interval = 8640000; // 1day -> h * m * s * ms NOTICE: milliseconds, not microseconds!
Vcc vcc(VccCorrection);
#ifdef MY_DEBUG
void before(){
Serial.begin(9600);
}
#endif
void setup()
{
pinMode(PRIMARY_BUTTON_PIN, INPUT);
}
void presentation()
{
sendSketchInfo(SKETCH_NAME, __DATE__);
present(PRIMARY_CHILD_ID, S_DOOR, "Reed Contact");
}
void loop()
{
int32_t timestamp = millis();
uint8_t reedState;
static uint8_t lastReedState = 2;
static int32_t lastBatteryReport = -report_interval; // for inital report
sleep(5); // Short delay to allow buttons to properly settle
reedState = digitalRead(PRIMARY_BUTTON_PIN);
if ( (timestamp-lastBatteryReport) >= report_interval ) {
uint8_t batteryPercent = (uint8_t)vcc.Read_Perc(VccMin, VccMax);
sendBatteryLevel(batteryPercent);
lastBatteryReport = timestamp;
}
if (reedState != lastReedState) {
// Value has changed from last transmission, send the updated reedState
send(msg.set(reedState==HIGH));
lastReedState = reedState;
}
sleep(PRIMARY_BUTTON_PIN-2, CHANGE, 0);
}
