Stuck at work with no network today but my phone. Trying to blockout a teensy project I'm going to write here tomorrow but I'm not sure how long elapsedMillis can run. Is it longer than a few hours? I found one thing about millis being good for something like 49 days before rollover with Google. FWIW project is to monitor a battery voltage and compute maH before VBat drops to 90% and log it and voltages to the serial port once a minute but compute maH once a second. Expected elapsed time is up to 6.5 hours. Last time I had to sit and wait with a voltmeter and a pencile and got lots less data than I hope to this time. Thanks if any can answer on elapsedMillis max value.