Power consumption L5

Now when the Librem 5 is starting to converge towards a finalized product (looking forward to get mine, and I don’t mind the waiting), do you have any measurements or educated guesses on its more exact power consumption (in watts)? The use case I’m interested in is when continously using a 4G data uplink and GPS (no display or wifi etc.). I would assume that the Dogwood and the Evergreen will be similar in terms of components, and therefore have similar power needs. Future SW can of course reduce this further, but we need to start somewhere.

To soon to answer.
Read this to know why:

Not exactly what you are asking, but here is some recent L5 power consumption news:


Note though that the question was about “power consumption in Watts”, not the run-time on standby.

It’s true, but you can link power and run-time by these equations:
power = voltage x current (id est W = V x A)
average current = electric charge / run-time
average power = nominal voltage x (electric charge / run-time)
Electric charge is 3.5 Ah.
In the video the nominal voltage of the 2000 mAh battery is 3.7 V, so we can assume the same value for the 3500 mAh battery.
In the video they explain that with screen off, modem on and 3500 mAh battery, the run-time is 7:18 (7.3 h) if WiFi is on, 11:48 (11.8 h) if WiFi is off, so you can get average values for power consumption in such cases: 1.77 W and 1.097 W respectively.
@olbender is asking for screen off, modem on and GPS on, but in the video there are not data about GPS, anyway the values I calculated should help.

1 Like

Nice calculations but I would just measure it (albeit that I would be measuring average AC input power i.e. would not account for inefficiencies in the AC/DC adapter and in charging).

Which is best? Depends why @olbender was asking?!?!

Some kind of data logging application with external DC power?? The L5 sounds like an expensive solution.

I don’t yet know for the L5 but continuous GPS use on my spiPhone is horrible for time-between-charges.

Thank you for the calculations. I think the values look quite OK, and they are probably good enough for a first estimate. I think that an active continuous data uplink might make the consumption increase significantly. I do not have any experience with the chip that is used in the L5, but for other LTE chips the consumption may increase from 0.005W (idle) to 2.5W (full steam ahead). The details for the L5 might of course differ but I think I could, based on your calculations, count on a consumption on 1-3.5W (even though 3.5 seems unlikely thinking about what heat that must generate in such small device). Thanks again for the calculations.

In the video the shortest run-time scenario with a 3500 mAh battery is 4:26 (4.433 h), when screen and WiFi are on, then in this case the average power consumption is 2.9 W, so values above 3 W are possible.
We experienced that L5 without kernel optimizations got hot quickly.
If we answered your question, please mark the reply that solved.


If you don’t mind looking a bit like a geek, one could always rig-up some kind of ‘bat-belt’ (think batman’s belt loaded with all of his superhero bat stuff) loaded with several small gel-cells instead of bat stuff. You might get 10 to 20 Amp-hours (50 to 100 watt-hours) of continuous power with the right setup, enough for a long day full of active use of your Librem 5 and still not look too geeky. But the phone would at least need to be capable of charging or running directly from external batteries when turned on, and have a long cord from your belt to your phone (for when you’re using the phone) to do that. You could strap the phone to one leg to help stay warm in the winter or use the back side of it as a plate to keep your food warm. Jokes-aside, I sit next to a PC for most of my work day or am in my car when not at my desk. So most of my work day my Librem 5 can be plugged-in and charging. But I’ll need that bat-belt on the weekends. That bat-belt isn’t just a joke. The closer the shipping date comes, the more I am asking myself exactly what I’ll need to buy to assemble it and how to minimize its appearance.

:rofl: Why not carry a car battery in a back pack?

Excess weight and unused capacity. The right belt might be practical.

that sounds like Morgan Freeman thinking out loud :sweat_smile:
if it comes to practicality then nothing beats the TROLL BELT …