xDrip » Features » Dexcom » Transmitter Lifetime
Transmitter Days
You can use a G5 as long as it has battery. This is because you can hard reset a G5.
You can also hard reset a G6 if its firmware is 1.6.5.25 or older.
You cannot hard reset the other G6 or Dexcom One transmitters. So, only start the counter if you intend to use the transmitter. The counter starts counting as soon as you insert the transmitter in a sensor. It could even start if you hold the trasnsmitter in your hand touching the contacts for a while. So, it’s best to keep the transmitter in the box until you intend to start using it.
The last day you can start (or restart) a sensor on a transmitter in native mode is when the system status page shows 99 (105 for G5) for “Transmitter Days” as shown in the following image.
After you successfully start a sensor, it will work for 10 days (7 days for G5 in native mode) as shown in the following image.
Hard resetting a transmitter does nothing to the battery. If the battery is dying, you will need to replace the battery.
