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How long is your Epic battery last?


How long is your Epic battery last?

Just curious about Epic battery, I charge my phone all night and start using from 8 AM. It is pretty down to 15% or 20% around 4 PM. Here are my normal usages: 1 hour of Google Map driving to work; checking email 4 to 6 times (set to refresh every hour); total talk time maybe around 45 minutes; few texting; browse the web perhaps 20 some minutes. I turn off WiFi, live wallpaper, and pretty kill all the active tasks from Task Manager. The only two thing that I have running are World Weather widget and Sense Analog Clock. How long is your battery last with the similar usages?

183 REPLIES 183

Light to moderate use and I get 10-12 hrs most days

Even so I have a charger at Home, work and in car just in case I need a top off.

I already had these USB chargers from my Palm Pre, they work great


Ok, here is my update.  This will be a long post to include all of the information.

i made the changes recommended by several posters regarding screen display (15 secs), keyboard display (same as screen), etc.  I verified that my display is at automatic brightness. I uninstalled Weather Bug.  I run Advanced Task Killer often throughout the day.

I had "normal' usage throughout the day consisting of checking emails, reading news, played a few games, received a text msg, looked at a couple files, edited some contacts and calendar appointments, checked the weather through The Weather Channel app, read a Bible verse.  With this activity i was able to go 9 hrs and 15 mins before i received the message that my battery was low.  After this period of time, my battery level was at 15%.  This is by far the longest that i was able to go before getting the message.

I'm still baffled by the battery summary.

  • Display - 72%
  • Cell standby - 13%
  • Phone idle - 7%
  • Android System - 4%

The item that complicates my test a bit is that i have two batteries.  one that came with the phone and the other i purchased at the same time.  Unfortunately i don't remember which came with the phone and which was separate.  here is the information on the batteries:


S/N:  AA1Z629xS/5-B  G9



S/N:  AA1Z810xS/5-B  G9


today i am using the first one.  Tomorrow i will be using the second in the list, which is from the same time period another posted having problems with.  it will be interesting to me to see if i can get 9 hrs out of the second battery.  i will post more after testing the other battery.


So I went to a service center last night and they told me that all that they would do is again swap out the battery on the phone.  I suggested that perhaps they have a bad batch of phones in my area.  The reps said that Epic was a battery hog, but that if I wanted to go back to the original store next week, they might have a new batch of phones.   They also told me to try the advanced task killer app and that I should buy a second battery to swap it out during the day.  This is rediculous.  Three visits and unsatisfied.  I'm ready to go back to my old Windows phone that is over three years old.  This is bad.  As a shareholder, I am very concerned about Sprint's turn around.

Message was edited by: mbermudez79

Message was edited by: mbermudez79


I am a statistician and I have taken on charting my Epic 4g battery life as a small side project.

I will post the full stats later, but I simply wrote down the time and the battery % (through the"battery indicator" app).

METHOD: These are projections from 100% life down to 0% life based upon the drain I got between 90% (when I got to work) to around 30% (when I did not want to risk running out of juice).  That is, I calculated the number of minutes per 1% of life then extended that out to a full 100% to 0% drain.

To keep functionality thoughout the day, we want to stay above 15% for a long day (18 hours from 100% to 15% = 21.2 hours total).


- Day 1: 12.3 hours.  Normal use of an 1-1.5 hours of screen time, 5-10 minutes calling and push mail--no wifi, no 4g, fring on, no task killers, latitude installed, GPS on in the power widget) around 12.3 hours.

- Day 2: 17.2 hours. After installation of juice defender.  No other substantial changes (sorry, it is real life and I could not do a controlled experiment).  I consider the reconnection to network services that juice defender does to be slightly annoying .

- Day 3: Same as above, but with GPS power in the widget turned off and change to fring. (Fring was connected to gtalk.  I removed the fring gtalk connection.)  Will post results of day 3 later today or tomorrow.


I think you might be right too!!!

I bought the extra battery & charger.  Unfortunately, I did not keep track of which battery is which, but the performance of one battery is completely different than the other.



S/N: AA1Z730tS/5-B     G9


This battery will only last 1-2 hours using 3G before it overheats & the phone shuts down with a battery overheat error.  (The performance is the same on or off the USB charger.)

My other battery will run 3-4 hours with no problems & will run all day on the charger.  (I'll repost that battery info later.)

Also, just a thought on the Display battery drain which I'll try to test.  Does having a Live Wallpaper affect battery usage?

This phone is absolutely fabulous, and if it turns out problems are from a bad $15 battery, it should be an easy fix.



11 hours is my best time. Last week end was a true test.

with lite surfing for prices, tweets, music, some pictures and texting i got 11 hours out of this sexy beast. i was so happy it went past the 1-3pm spot my hero would always die at.


Yesterday, i reported on the results of using my battery built in June.  Today i used my battery build in August.  It lasted for 8 1/2 hours before it got to 15% and displayed the messge to plug in my phone.  This is 45 minutes shorter than my other battery but as someone else mentioned, it is hard to do an exact comparison.

I have a couple questions for the group:

1)  Does it take your phone 3-4 hours to recharge when you plug it in at about 15% battery left?  Mine does it seems like a really long time.

2)  There have been several postings regarding Juice Defender.  Please let me know if you use it (or have used it) on an Epic and how it is/was working out for you.  Has anyone used the BatteryFU battery saver app?  Both Juice Defender and Battery FU have about the same rating.  Both have people that rated it as a 5 and others that rated it as a 1.  There are many more users of JD, but there are people that use BF that think it is better.  I would appreciate your input in helping me choose between the 2.




Ok ive come to a conclosion of everones promblem with the battery, first off: it takes about a week for the battery to break in, that means charging to full every night for a week and then letting it get low everyday. Also the default settings for the phone are crap, disable all auto sync options and get rid of google talk (no one uses this) turn of 4g, bluetooth, wifi, and gps unless you are actually using them, I have had people tell me the phone will last 12 hours like this with constant use and over 20 hours with mild use


It takes 4 hours to charge mine completely.  I suspect this is too long. Does anyone charge it in about an hour?


Here is what I have noticed with my EPIC

From about 10% charge left on battery

It usually takes about 1-2 hrs to get about 90% charge.

It takes another 1-2 hrs to charge the remaining 10%


How do we remove Google Talk??

No use for this


I've found that the JuiceDefender application works well for me. It easily gives me a 50% boost on battery life by managing the data connection (number #1 killer of the battery life). It shuts down 3G and uses 2G to receive voice and texts. It does turn on the data every so often (1 minute every15 by default) so you can still get updates every 15 minutes.

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