user guide

Understanding Battery level

How long does an Asteri battery last and how does that correspond to the (4) Battery status LEDs on the front of the Asteri?

This is a question we get all the time. The answer is a little complicated though. We rate the Lithium Ion Asteri battery as an All day battery. However, the amount of time it lasts will depend greatly on which model of Asteri, what options are enabled and how many satellites it is tracking.

For instance the X1i, which is a 72 channel Single frequency GNSS receiver, will last well over 14 hours on a charge. The X2i, which is a 200 channel Dual frequency GNSS receiver, will last over 10 hours. Finally, the X3i which is an 800+, Multi frequency GNSS, with Atlas LBAND corrections and powering an external antenna may only last 6-8 hours.

This is because each receiver is going to have a significantly increased power demand based on what it is doing, yet all use the same battery.

So, how does that relate to the (4) LEDs. As an easy explanation, we tell people that each LED represents approximately 25% battery life and it will flash when it gets to 10% battery life. How long that percentage lasts will be based on the Asteri model, how many channels are working, how long you are connected to bluetooth and if you are running an external antenna. However, that is actually a bit of an oversimplification. The LEDs actually work on a battery voltage level.

A fully charged Asteri battery will read 8.4v when it is brand new. This represents all (4) LEDs. The Asteri also needs at least 7.0v to run. So, the LEDs on a brand new battery would work like the chart below.

  • (4) LEDs on when it is at 8.4v
  • (3) LEDs when voltage drops below 8.25v
  • (2) LEDs when voltage drops below 8.0v
  • (1) LEDs when voltage drops below 7.75v
  • (1) LED when voltage drops below 7.5v and Flashing when it drops below 7.25v

If you made it this far in the support article, the next thing you will say is, "My 4th LED only lasts about 10 minutes, there must be something wrong with my Asteri."

Well, not really. The issue is that while Lithium Ion batteries don't build "memory" like traditional batteries,  they are affected by age and adverse temperatures (hot and cold)… So, after a few years and being used in 100 degree weather, what your actual graph might look like is this:

First, it never gets 100% charge, because it won't charge to 8.4v any longer, so the battery is now only lasting 6 hours.

Next, the voltage level goes to 8.25v after only 15 minutes, but it still has 86% battery life left. LED (3) goes out at 4.5hrs remaining, LED (2) at 3.3hrs remaining, LED (1) at 2.5hrs remaining, and it actually begins flashing at 1 hour remaining, but might not make it the full hour, because the voltage drop accelerates toward the end of the battery charge.

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