Purism's Librem 5 "Dogwood" Seeing Improvements In Battery Life

Purism has revealed more details about their improved "Dogwood" batch that will be soon shipping for their Librem 5 GNU/Linux smartphone. The battery life is longer but still short of what is provided by modern day flagship smartphones.

Dogwood is the batch of the Librem 5 smartphone with significant hardware improvements as well as continued software improvements. Librem 5 Dogwood flips the SoC to the other side of the PCB to improve heat dissipation, upgraded to a 3600 mAh battery that is 75~80% larger than what shipped on prior revisions, and more robust build quality of the chassis/device itself.

Dogwood was supposed to be shipping in Q1 but saw delays due to the coronavirus and other issues. The Dogwood batch is expected to begin shipping in the weeks ahead and ultimately followed by their "Evergreen" batch that is expected to be close to a finished product.

Today Purism shared details on the thermals and power / battery life for the Librem 5 Dogwood. Their results show that Dogwood is running about four degrees cooler than the "Chestnut" batch.

With the ~75% larger battery but with higher power draw of Dogwood, the company says this is around 60% more run-time compared to Chestnut. In a graph published by Purism it's still a ways out from competing with modern day smartphones:

- The idle battery life is just under five hours with the screen on. On another graph looking at the battery life with the screen off it appears to be just over 35k seconds, or just over nine and a half hours. Still not to get through the day and that's assuming not interacting with the phone at all, but at least better than before where the Chestnut revision got less than six hours of battery life with the screen off.

- For battery life if just making phone calls, it's just under four hours.

- If watching videos via GNOME Web, there is just over a two hour battery life.

- Other mobile workloads put the overall battery life in the 2+ to less than four hour range.

They remain hopeful though of being able to squeeze out a longer battery life with additional software optimizations like supporting suspend-to-RAM. Details for those interested via this blog post.