eelink device power consumption minimisation

Ob1a year ago

hi all,
I have an eelink device (TK419 specifically) and it's working perfectly. I now want to tune it for minimal standby power draw when the car is parked. I understand that the commands likely to have most impact are:

GSM,[MODE],[T0],[T1_TOTAL],[T1_WAKING],[T2_PERIODIC],[T2_WAKING]#
GPS,[MODE],[T0],[T1_TOTAL],[T1_WAKING],[T2_PERIODIC],[T2_WAKING]#

Does anyone have any experience changing these settings? Why does it support both a single "phase 1" on period and then a repetitive "phase 2" on period? Do i need to align the heartbeat interval (HBT command) with the "on" periods of the GSM and GPS?
I'm considering setting both to "mode=1", with really long "off" periods. This means that both the GSM and GPS only come on rarely for a general ping, or otherwise if the device goes into "active" mode (moving or ignition on)....any downsides to this?

Ob1a year ago

OK for those playing at home....I've tested both commands with great results. OOTB standby current draw (with both GPS and LTE always on) was about 50-60mA at idle. I ran this command first:
gps,1,120,0,0,60,2#
Which means GPS module only on when any of:

  • ignition ON
  • for 120 seconds after ignition goes OFF
  • 2 minutes every 60 minutes with ignition OFF.
    This took standby current down to ~10mA (pretty good). The unit continues to show as "online" almost continuously and has no dramas tracking immediately after ignition on.

I then also tried:
gsm,1,120,0,0,60,2#
Which means use that same criteria above to turn off the LTE modem. It reduces standby current to 2mA (yes!!), but at the expense of having the vehicle show as offline or unknown status almost always when parked up. It comes back online within seconds after IGN comes on. This mode is best for extreme power saving, but is probably pretty poor in the situation where your car gets stolen on a flat bed truck (no ignition required). You can't even SMS it to get a live position update.