DC power specifications


#1

Concerning Librem 13 Version 2 laptops,

  1. What is the constant input voltage [V] that needs to be applied at the DCIN socket by a power supply, and the input voltage range tolerated by the Librem system?

  2. What is the maximum load current [A] that a power supply should be capable of sustaining through the DCIN socket?

  3. What is the nominal electric power [W] consumed by the Librem system with no peripheral devices attached? How does the electric power vary per different operation modes?

modes
  • running on battery alone
  • sleeping on battery alone
  • running on power supply while charging the battery
  • sleeping on power supply while charging the battery
  • running on power supply with full battery charge level
  • sleeping on power supply with full battery charge level
  • turned off while charging the battery through power supply
  • turned off while maintaining the full battery charge level through power supply

https://www.crowdsupply.com/purism/librem-13

https://en.wikipedia.org/wiki/Power_supply
https://en.wikipedia.org/wiki/Electric_power


#2

I haven’t owned this laptop. But I can’t imagine it to be totally different from other models. For the components my guess is as following. I can’t imagine it to be a lot different than that.

The battery has 45w/h and 2 cells (7.4V). Taking into account fast charging with 1C (45w) and max load of 35w (which will drop anyway to ~25 after a short time period) a 80w power supply should do the job perfectly. I believe even a 60w power supply should not hinder in any way.

My guess is that the internal voltage regulator works with 12+V. So anything from 14-20V should be fine. Amperes would be 3A (20V) 4.3A (14V).

With ThinkPads I have experienced that the voltage Input is quite flexible (nominal 20V, but works with 15-23V)

How accurate do you need to know?