This is why your battery drops 10-15% in the first 20 minutes.

[ihbsbA]

You are absolutely wrong. I have been plugging mine in each night and it is on all night while plugged in and it is fine the following day. I get awesome battery life.

Stolirocks, when you wake up, look at your battery indicator. It won't have a lightning bolt anymore because it's fully charged and stopped charging. OP is correct, it stops charging.

Sent from my rockin' Evo.

 

[ihbsbA]

I'm going to search for an auto off app... set it to turn the phone off about 3 hrs past the time I go to bed and back on when I wake up.

Sent from my rockin' Evo.

 

[xorbe]

Well, yes of course it stops charging ... lithiums do not trickle charge to maintain, they will puff and vent and catch on fire!

But, the phone should be running from the charger power, and the battery should be idle at 100%! After the lithium cools down and the voltage drops from 4.20v slightly, you might be able to unplug and replug and squeeze in a few more mAh.

 

[Disgustoid]

No widgets, no live backgrounds, no notifications/alerts, no social networking enabled- sync email ONLY when you access the mailbox, turn off vibration completely, run in completely silent mode (no ringers no chimes.)

IF you do all that, I'm sure you can get at least 24+ hours of casual use...but 43 HOURS? Wow. I haven't done that since my Nokia dumbphone days.

I actually do all of the things above with my EVO except for notifications/alerts and ringtones and I'm certain I can get 24 hours of casual use. I blame the Pre where I did all those things to conserve its horrifically bad battery, and those habits followed me to the EVO.

I'm pretty certain that with these settings, the phone would be dead in 43 hours unless it was completely untouched, in which case you MIGHT have a sliver of battery power left.

 

[Edge767]

AMEN.

Sent from my rockin' Evo.

As someone else put it so clearly: The Evo is like a Maserati; you drive it hard and it gets poor fuel mileage. You can't expect the fuel economy of a Prius from a Maserati. Even driving a Maserati reasonably will not get the same fuel economy as a Prius. Why? 'Cause it's a Maserati.

I'd rather have the Maserati than a Prius.

To take it further: One of my daughters has a Hero and the other has a Sprint Reclaim. The Reclaim (the Prius of the bunch) gets great battery life. The Hero (like a Camry or Accord) gets decent battery life, but not quite as good as the Reclaim. The Evo is the sexiest, fastest, and most full-featured of our phones, but it pays for it in terms of battery life.

With that said, my battery lasts me a full day with normal (medium/heavy) use. I don't use task killers or anything like that, but I did turn off stocks and news polling.

 

[Gekko]

As someone else put it so clearly: The Evo is like a Maserati; you drive it hard and it gets poor fuel mileage. You can't expect the fuel economy of a Prius from a Maserati. Even driving a Maserati reasonably will not get the same fuel economy as a Prius. Why? 'Cause it's a Maserati.

I'd rather have the Maserati than a Prius.

To take it further: One of my daughters has a Hero and the other has a Sprint Reclaim. The Reclaim (the Prius of the bunch) gets great battery life. The Hero (like a Camry or Accord) gets decent battery life, but not quite as good as the Reclaim. The Evo is the sexiest, fastest, and most full-featured of our phones, but it pays for it in terms of battery life.

With that said, my battery lasts me a full day with normal (medium/heavy) use. I don't use task killers or anything like that, but I did turn off stocks and news polling.

Maserati is junk. the EVO is a Ferrari.

 

[jedisrus]

Back to the original post I wonder why my EVO does NOT drop 10-15% in the first 20 minutes. I too charge my phone over night. And when and if I bother to check my battery percentage I never drop more than 7% in the first hour of use unless I fire up a video.

 

[rem_kujawa]

I don't know but I get great battery life. My up time is going on 18 hours and I have 69% left.

 

[scott_0]

What is the point of anyone having this phone if they run it like that? LOL, It is a power phone we have to just do the best we can with what we have.

thats how I feel, Im not nuetering my phone to save battery power. I simply bought a second oem htc battery

 

[scott_0]

I'm going to search for an auto off app... set it to turn the phone off about 3 hrs past the time I go to bed and back on when I wake up.

Sent from my rockin' Evo.

yes! keep us updated on what you find. thats one feature I miss from my black berry

 

[ksuwald]

I put my phone in airplane mode last night while charging. As soon as I took it off the charger within 5min I am down to 91%. This damn thing is going back to Sprint. I've tried everything. I can't get 5hrs out of my phone on minimal use.

 

[soldierblue]

I think the actual reason is that the phone, for whatever reason, doesn't trickle charge. It charges up to 100%, and then stops. You use it while it's plugged in (or idle battery usage happens or whatever), and the EVO still erroneously reports 100% charge (which it isn't). So you unplug it and it reports the correct charge.

 

[drdrewdown]

i'm using JuicePlotter to try & validate some of this.. to anyone interested in this topic i would highly recommend this application. it can tell you a lot about what your battery is doing & i have not noticed any ill effects.

 

[meyerweb#CB]

I was having similar questions about charging and why power drops so quickly. I have noticed if I charge the phone in the off mode, and the green light goes on, I unplug it and shut it off for the night. When I turn it on in the morning, it is not 100%. It is usually anywhere's from 99% to 96%, never 100%. Now when I charge it off first and it hits green, I unplug the EVO, turn it on, plug the charger in and wait till it gets to 100% again, and then shut it off, and when I turn it off, it is 100%.

I think you should be careful with this technique. One of the weaknesses of Lithium batteries is that they don't handle overcharging well. In fact, overcharging is really very bad for Li batteries, and will dramatically shorten their lifespans. In fact, even discharging and recharging to 100% frequently will negatively impact battery life. Electric cars with Li batteries, for example, typically keep the battery charge between 25% and 75% to ensure maximum lifespan of the pack. Of course, it's a bit more of a worry when you're talking a $10,000 pack vs. a $10 phone battery.

I think the EVO charging circuity is ensuring the battery isn't damaged by shutting of charge slightly below 100%, and the technique you describe above is bypassing this safety margin.

Does starting the day at 96% vs. 100% make THAT much difference in how long the battery goes during the day?

 

[Eazy123]

At work just now, I had the phone charge until the light was green, unplugged it and 20 minutes later it's at 94%. This is odd.

 

[xorbe]

At work just now, I had the phone charge until the light was green, unplugged it and 20 minutes later it's at 94%. This is odd.

I ran a little battery test yesterday, and at around hours 7-10, it was only dropping 1% per hour.

However, the first hour it dropped 6%. This is not because it was sucking a lot of juice -- it's because lithiums cannot be linearly charted. I gave up after 10 hours because it was headed towards 38+ hours.

ie, the moral of the story is, don't extrapolate from 20 minutes worth of data.

(Today I'm running a test with Meebo IM client running, which keeps the phone awake ... as all Android IM clients seem to do.)

 

[TrueDrooid]

I really thought my Palm Pre had it bad. Im really limiting my web activities and usage to limit how much time I have to keep this phone plugged in. I just noticed this mystery battery drain this week.

I had my phone at 100% before I left for work and THIS time I immediately placed my phone in airplane mode and wahlah.. 15-20mins later when i got to work & still in airplane mode, my battery was down to 90%
This is a Problem.

 

[BradJ]

I too can confirm this:

I charge my phone overnight. Throw it in my pocket when I leave for work. Once I get to work 30 minutes later the battery is reporting 90% without even using it!

Topping off the battery before I leave for work gives me much better battery life throughout the day.

 

[Jesse]

Purchased a Kill A Watt to monitor the Evo's electrical draw during charge. Updated first post with some initial findings.

 

[gbm85]

Purchased a Kill A Watt to monitor the Evo's electrical draw during charge. Updated first post with some initial findings.

Jesse, thanks for doing this research. It's definitely disheartening that the EVO doesn't run off AC once it's fully charged.

Last night, I turned my Evo off to charge it. When I turned it back on this morning, it dropped to 93% in about 10 minutes. So there's probably more to this story. But thanks for writing the first chapter!