I went on a camping trip last month with my son’s Scout troop to a site without any electricity. I have a Samsung Galaxy S5 smartphone with a Sprint plan, and when I’m roaming away from home in remote areas with sparse coverage I find the battery really takes a beating. However, I need to be available to the outside world in case someone needs to contact me or one of their sons, so powering the phone down at lights-out isn’t really an option.

Therefore, I tried out the Ultra Power Saving Mode (UPSM) feature on my phone for the first time. Released with the S5, UPSM is also available in the S6. It’s an extreme “Shut it down! Shut almost everything down!” (I’m channeling the electrical worker from “Die Hard”) feature that enacts the following changes:

  • Blanks the homescreen
  • Changes the interface to greyscale
  • Lowers the brightness
  • Reduces CPU speed
  • Reduces display refresh
  • Ends all running processes/services
  • Turns off Wi-Fi and Bluetooth
  • Changes data connection to 3G speed
  • Turns off mobile data entirely when the screen is off

Essentially, it’s meant to allow phone usage and texting only but you can also choose other apps which can run in UPSM such as email, social media programs, the calculator, the clock, or the web browser. The maximum number of apps you can run in UPSM is six.

To enable UPSM, swipe with two fingers from the top of your screen:

Tap “U. power saving” (you can also go to Settings, Power Saving and toggle “Ultra power saving mode” to On).

Once I did this, I received a notification that enabling UPSM would provide me with about 11 days of maximum standby time. I tapped “Turn On” and the screen went grey then dimmed.

I couldn’t take screenshots with UPSM enabled, but I was able to snap a picture of the next screen with another camera:

My phone displayed the enabled default apps which consisted of Phone, Messages, Internet and Clock.

The plus sign icon allowed me to add these other apps:

  • Calculator
  • Facebook
  • Google+
  • Memo
  • Twitter
  • Voice Recorder

I chose to leave the default apps as is. While writing these details down I noted the screen blanked very quickly (about 10 seconds) while using UPSM, showing how brutal it is about reducing power consumption.

If I tapped the “Menu” icon (three vertical dots in the upper right) it showed controls to remove any added apps to run in UPSM or configure additional settings such as:

  • Wi-Fi
  • Bluetooth
  • Airplane mode
  • Mobile Networks
  • Location
  • Sound
  • Display

With UPSM enabled my phone went from 93% at about 11 AM to 91% by 7 AM the next day. There was a surge of power consumption when I turned it on, which is understandable since everything fired up once more and the display/CPU/network usage began spiking up.

Samsung claimed at release that UPSM could keep a phone alive for 12 ½ days. Someone tried this option on a cross-country trip and reported that after turning it on they were able to drive from New York City to Los Angeles in a week with 7% battery life to spare. However, the article is quick to state this “in no way is indicative of real-life.” After all, the phone wasn’t used at all on the road trip, which would hardly be the case with us smartphone aficionados. But it’s an interesting assessment as to how conservative the power consumption on the phone becomes when UPSM is on.

I carry spare batteries on camping trips, but with no access to electricity even the most conservatively-used phone will die fairly quickly without UPSM. Ditto for the spare batteries, which only buy you time. UPSM is a simple yet powerful (pun intended) method to be reachable – or dial out – in emergencies and keep at least one toe firmly on the grid while enjoying the great outdoors (or wherever else you may happen to be).

See also:

Windows 10: The smart person’s guide

Pro tip: How to use the calling features of the Apple Watch

The Distiller App: A Portal to the World of Whiskey

When it comes to tech budgets, it’s time to make money matter