• After 15+ years, we've made a big change: Android Forums is now Early Bird Club. Learn more here.

Astonishing Battery life discovery!

linzgeneral

Well-Known Member
May 29, 2010
108
20
irst off, I love my Evo and it has been relatively problem free with one exception, that of a very poor battery life. With modest use I would get about five hours before it is completely dead. I have tried most of the battery life tricks and applied the latest software update (successfully the first time) all to no avail.

Every night, i plug in my phone at about 12 AM and take it off the charger at about 8 to go to work. I noticed that almost immediately or at most within a few minutes, the percentage drops about 10 points. I usually charge it back to 100 percent but the rapid decline to total discharge during moderate consistently persist.

However I was so tired last night that I was unable to charge my phone overnight. This wasn't a concern since I knew that I was at about a 90% charge and would probably be close in the morning. When I woke up, I figured I would put the phone on the charger while I got ready, it wouldn't be at 100% but close enough I guess. I got ready and took the phone of the charger showing 98% at exactly 7:30 AM.

I get to work and have sent about 7 texts, being playing with the phone awhile. At about 9:30 the phone is showing 97%. I am thinking hmmmm....but no biggie. At 11 AM it is showing 96%. I actually sent a few more texts and scrolled through some emails. While at lunch, I check the phone and at 1:15 PM, the phone is showing 92%. Normally with the way I had been using it, it would have been in the low 70s or even 60s. Then it hit me. However this baterry is calibrated or the phone is reading the battery, I dont think that WE ARE SUPPOSED TO CHARGE THE PHONE BEYOND A FULL CHARGE.

I remember similar posts but I dismissed them as hogwash until I have seen it for myself. Its weird but apparently true. In the month that I have owned this phone I have never seen my battery perform like this. Anyone else can confirm my theory or add further clarification? Just check my percentage at 1:37Pm and it is at 90% after 6 hours off of the charger. That's an 8% decline in 6 hours; interesting to say the least. I am truly excited!

UPDATE: GOT OFF WORK AT 11 PM. AFTER 14 PLUS HRS, BATTERY READS 82%. NORMALLY IN WOULD HAVE BEEN 20% OR LOWER.
 
  • Like
Reactions: skpd
If left on while charging, once the phone hits 100%, it starts running off of battery - but continues to show 100% charge.

This prevents overcharging the battery - something that could produce dramatic results - like total battery destruction, total phone destruction....

After being unplugged, it takes a short while for the phone to show its true charge level.

This is identical to the behavior of most laptops.

I'm using a laptop right now - widget says I'm at 100%, unplug - it's instantly at 99%.... Now 98%... Very, very soon, it may go as low as 92%. Or maybe a bit above that.

Most people think that laptop battery use time is a lie - just as they are thinking the same thing for an EVO - when it's really a simple matter of understanding the charging cycle.

When Apple, Dell and HP fix this for their laptops, I'm sure EVO and others will be close behind.

In other words - don't hold your breath, it's not a bug, it's a feature.

And why is this so prevalent on the EVO and not so much on other smartphones?

Wait until other power-hungry, super smartphones hit the market. Guarantee they'll have the same confusion/issue.

Have you seen the display size and CPU/GPU/Memory specs on your EVO? It's got more in common with a small laptop, aside from hard disk, than most smartphones.

That's all that's going on.

So - yes - disconnect when at 98 or 99% - or the very instant the LED up front turns green and it'll last longer.

But - don't sweat it, you're not destroying your battery or overcharging it beyond a full charge - that's exactly what's not happening, by design.

And don't expect EVO to fix this - it's basically the standard way things like this work...


The only thing that they could really change here is the set-point where the battery drops low enough during plugged-in-but-running-off-the-battery to trigger charging. Most folks, me too, see their phones more quickly go to around 92 or 93% if left on the charger too long - so - guess what I'm thinking that set point is? ;)

But whatever the set-point for that charging switch is - the overall behavior will remain constant.

PS - My laptop just leveled out at 92% - 20 or 30 minutes after I started writing this. And there's absolutely nothing wrong with it or its battery.
 
Upvote 0
There should be an option to trickle charge or quick charge.

Just like all the laptops that DO NOT have such an option? ;)

Battery tech is not advancing as fast as the devices they support.

I applaud your idea, it's a good one from a certain point of view, but won't hold my breath for it.

The battery option I'm waiting on is superior battery technologies - and with luck, those will get out of R&D and into our hands soon enough. <fingers crossed>

Here's one slice of the possible future...

Lithium-air
 
Upvote 0
I dont think that WE ARE SUPPOSED TO CHARGE THE PHONE BEYOND A FULL CHARGE.

This is absolutely true, thats why the batteries in our phone are "smart". They include circuitry to prevent overcharging. If they didn't, we would probably have exploding phones on our hands.

Now that being said, a rule of thumb is that a Lithium battery degrades (not discharge, big difference!) faster at the extreme ends of the charging spectrum, meaning above 85% or below 20-15%. So when you can help it, try not to keep lithium powered devices on the charger all the time (eventually it will kill it capacity, little by little), dont let it discharge all the way if you don't have to, and if you are going to store it for an extended period of time, shoot for a 60-70% charge.

That being said, I'm not sure that's the source of your new found battery endurance.

I've read in a thread here, that there are certain tricks that help battery life (i suppose what folks are really doing is "calibrating" the battery with charging cycles), such as one backed by HTC:

Charge for 8 hours straight with phone one
Turn Phone off, charge for two hours
Turn Phone on, charge for one hour
Turn Phone off, charge for another two hours

Turn phone on and enjoy newly found battery endurance.
 
  • Like
Reactions: midget and EarlyMon
Upvote 0

BEST TECH IN 2023

We've been tracking upcoming products and ranking the best tech since 2007. Thanks for trusting our opinion: we get rewarded through affiliate links that earn us a commission and we invite you to learn more about us.

Smartphones