Battery standby time on devkits?

I know, devkits are intented to be used wit ac-power adapter,
But you can use an external powerbank to power it.
And if you do that you could do some tests like

-Measure battery standby time
-Measure battery time with devkit functioning.

This could give us an idea what Librem5 battery duration would be.

Anyone did the test?

Not that I know of. Things are evolving with respect to power management, so you would only get a vague idea of what battery life would be, though I realize that it would be useful to have that information.