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View Full Version : Your Phone Is Lying About The Battery Level And Signal Strength


Ed Hansberry
07-30-2008, 08:00 PM
<div class='os_post_top_link'><a href='http://www.dansdata.com/gz084.htm' target='_blank'>http://www.dansdata.com/gz084.htm</a><br /><br /></div><p><em>"Your mobile phone is lying to you. So is your laptop. And not just when they whisper to you in the night.Mobile phones, and most modern laptops, have signal strength and battery life displays. One or both of these displays has probably been the focus of all of your attention at one time or another.Neither display is actually telling you what you think it's telling you."</em><br /><br />Here is an interesting article on what your battery indicator and signal strength icons on your phone are telling you. It explains why when I am sometimes in an area that has "full signal strength" that calls are dropped or of really bad quality.<br /></p>

nmcclana
07-30-2008, 08:20 PM
That explains why my piece of crap Apache shows 4 bars - then when I actually connect it drops to 1 bar. Good article!

Brad Adrian
07-30-2008, 08:56 PM
That explains why my piece of crap Apache shows 4 bars - then when I actually connect it drops to 1 bar. Good article!
...and how I can maintain a look of complete attention on my face no matter how long my wife talks to me.:rolleyes:

Reid Kistler
07-30-2008, 09:27 PM
Interesting article on both counts!

The Signal Strength vs Interference problem applies not only to cell phones: many FM receivers also display Signal Strength - but a relatively few (at least at the Affordable Price Points) also display Multi-Path Interference: with my old Marantz, you often get noticeably better sound by adjusting the antenna for Minimal Interference as opposed to simply Maximum Signal Strength...

The battery gauge is a hoot: my Razr will display 2 bars, but plug it into the Charger and it immediately drops to 1 bar.... Leave it in the charger for only a few minutes it comes out right up to Full Charge!

Cynical view of American Mobile Phone Service Providers however - surely NONE of them would spec a phone that Deliberately Misleads their customers?!?!? :rolleyes:

subzerohf
07-30-2008, 11:03 PM
Another example is the speedometer of my car. The reading from the speedo is always faster than the reading from another source, say a GPS. The manufacturers probably say that it is a safety feature.

plasticbiker
07-31-2008, 03:47 AM
Just a thought, but it would take more cpu cycles to accurately measure the battery and signal strength.

The code required to quickly check the signal level, is 1/3 the code to measure the signal strength, noise level and calculate the snr. This might seem like a minor thing, but in an embedded environment, every cpu instruction counts. You also have to figure in the fact that the signal calculation is performed every 15 to 30 seconds.

It all adds up to reduced battery life to perform the extra calculations over and over again. So they sacrifice the accuracy of a few widgets to give you better talk/standby times.

JKingGrim
07-31-2008, 03:50 PM
Another example is the speedometer of my car. The reading from the speedo is always faster than the reading from another source, say a GPS. The manufacturers probably say that it is a safety feature.You are right! My speedo always seems to be reading a speed higher than the speed limits. Even when I drive the same speed as the cops! :)


"And remember: Measuring signal without measuring noise is like only counting the goals your team scores." <-Good quote.

I bet thats why most phone battery meters only have 3 bars now. What can you really tell from an indicator that only has 3 levels? I bet the categories are something like 100-50%, 50-25% and 25-0%. My PPC 6700 reported the battery in 1% increments. New WM devices only give it in 10% increments, though it can be hacked to be 1%.