I was under the impression that when Extended Tracking (XT) is enabled, all radios in the unit are turned off and the unit is in nearly sleep mode until the time when the next track point is to be sent. Then it wakes up, sends that point and checks for messages, then goes back to sleep. If this were the case, the battery would last a lot longer than when in normal use mode where it is constantly monitoring GPS and more frequently checking in with Iridium. But that is not what's happening, XT is sucking down my battery.
I have the unit set for no track sending and no track logging (I log tracks on my watch and use occassional preset messages to send check-in's that have Lat/Lon) so I don't drain the battery all that fast in normal use. However there are times I'm in dense forest or canyon that does not have good view of the sky to connect with Iridium. Then the unit eats battery trying to reach Iridium on update intervals, just continuing to pound out power to reach a satellite. That is to be expected and the way it should work. In this use model my unit consumes about 7% battery in 10 hours (0.7 % / hour over a 24 hour test). As another test, in this configuration I put the unit in my basement where it is not going to connect to Iridium and even in this fashion it burns about 3% battery / hour trying to reach the satellites.
So when the unit is put into XT, one would think it would stop trying to talk to Iridium since there is nothing to send. Tracking interval is off, so it should not wake up and try to talk to Iridium. It's just hanging on my pack so I can send a checking-in preset every few hours. Battery life should be better than all of the above scenarios. Yet in a test case of this the unit consumes battery at an insane rate if it can't reach Iridium - but it should not be trying to. If I put the unit where it can see the sky while in XT, it burns the same 0.7 % / hr. If I put it in my basement, it sucks down 7% / hour. Worse than having XT off. This makes no sense.
What I'm trying to do is determine the best configuration to make the battery last as long as possible on a multi-day trip while still having it turned on for quick preset message sending. Recognizing that at times I'm not in good sky visibility.
What am I missing on how XT works? Or is this a code bug that makes the unit turn on the radios (I'm guessing Iridium) even when in XT?
