My Note 2 with DN4 ROM was shutting down at 10~30%, i.ve charged it to full, then discharged it to 0% for several times, then used this as recommended, shut it down, pull out the battery, put it back and did one more cycle of discharge-charge, and now it indicates the correct battery level! It doesn.t do much, it just erases a file anyone could do, but hey, what it does is great! 5/5

This app will *not* improve your battery life. Any improvement is merely perceived due to the phone reporting the correct battery level. E.g. before calibration: 4 hours to 70% -> 1 hour to 0% and after calibration: 1 hour to 80% -> 1 hour 60% -> 1 hour 40% -> 1 hour to 20% -> 1 hour to 0%. That said, this app does exactly as described. 5/5

The whole point of this app, is to remove the batterystate.inf. This file saves the charge information, when it's deleted, the battery is starting again, as in a brand new condition. However bare in mind, it DEPENDS on how old and how many charges the battery as received. The more charges a battery receives the shorter the battery life becomes. No amount of removing the stats file, will compensate for an old battery or dying battery. Replace battery, new battery should already be calibrated, if not calibrate it. I always calibrate before charging, while I am draining the battery. This way when I charge the phone to 100%, i re-calibrate. Why? because by doing this, I am making sure the batterystats file see's the real charge information as opposed to randomly charging and discharging which can damage a battery's life expectancy. You only need to do this around 6 month's..unless you notice oddities in battery length..which might be battery fatigue..ie its dying and you need to replace..at least by calibrating you get a good idea whats going on with your battery, even if it does little for you because of a badly decaying battery 5/5

Battery Calibration goes to black screen when I start it then I have to press home to leace the app only worked once cleared data forced stopped it and reinstalled it still the same 4/5

I'm waiting for it to drain and then ill fully charge it after. Rooted Droid 2 liberty v.8 running tweaks :) 5/5

t's doesn't worked on my Galaxy Ace,it's still showed me fake battery status.. please fix this 2/5

Does nothing I have tried it several times per the instructions. Has done nothing at best & seems to have made it much worse. Galaxy Tab 7 1/5

Rooted, custom ROM, noticed batt was a bit rubbish, after calibration a year ago was easily 2x as good. About to try 2nd calibration before going away as it hasn't been so great the last week... will report back... 5/5

At first I was impressed, how much juice I can get from my device after running this app. Srsly, when I ran it on 100% batt, I got 2 days from my Gallaxy Note 2 with Android 4.3. But when I plugged it in to charge, charger simply does not follow simultaneous usage of the phone. Not in my car, not via PC, not directly into charger - battery drains faster than it charges. Could not charge over 30% even after full day being connected! Ideas welcome. ADDED: Raising from 1 to 3 stars because of developer's quick response, but problem still persists. 3/5

This app works 100%. Your phone should be rooted. Just do as it says. Charge till 100% and then calibrate. And after this please let your battery completely drain to 0% . Charge again till 100% and then use normally. 5/5

I used this on 2 of my devices (android cliq and gs3), both were having battery life problems doing normal activities, after a ROM install. Then I downloaded this, charged to 100%(let it sit at 100% for like 5-10 mins) pushed the calibrate, it did its thing and wow longer life.. What else can I say? 5/5

Calibration done.. I followed all the instructions. Okay. But now my phone is taking 8 hours to fully charge!! What have this app done to my phone?? 1/5

No placebo effect here. Even without using my phone had bad battery drain. I would reboot & jump 30%. Recalibrated, and after 7 hours & 2 restarts, still at 90%. Droid X2. 5/5

However, why does my battery voltage stays at 3 to 4mv? Please help, once fix I will rate 5 stars 3/5

Does exactly what it says on the tin, doesn't extend battery life, just makes the battery meter more accurate after new ROM installed. So many fools on here complaining because they lack basic reading skills!! 5/5 5/5

The device is still rooted, but the app does not seem to recognize it. A fix is desired. Thanks! 5/5

Can't say this helped matters any, even after following directions. I'm seeing roughly same performance from the battery. Maybe it's just a lousy battery. Besides, fully discharging a lithium ion battery is NOT a good idea & actually decreases the life span of the battery. Dev should advice accordingly. 4/5

If u rate this one star its prolly because 1. Ur device is not rooted with cm7 rom on it like mine. 2. Your too stupid to read and to have android 5/5

Droid 2 doesn't work. Root first, 100%, plugged into power, calibrate, then fail. Am uninstalling. 1/5

Doesn't work on HTC EVO 3D 2.3.4 rooted 1.5hboot it can't find the file :( sad cuz this app was one of the reasons I rooted 3/5

No idea why but seemed to work really well for aprox 2 days, there for 5 starts Galaxy S4 LTE Android 4.4.2 (pretty sure is in the android 4.4.2 the problems is) App works great tough 5/5

As battery gets old its capacity goes down but setting file that gives your percentage doesnt update(battery drops suddenly from x% to y% cause the expected capacity and actual doesnt match ).This app updates that and gives exact percentage.do you think it helps battery life?it gives perfect reading nly.so dev thank you for making such a great app. 5/5

I believe this app is good as on xda, but when I open this it stucks at black screen=not responding pls fix and will give five stars. 1/5

Is good to the redness of the coconut ladder. The percent of glue needed to achieve the lateral stabilization is 5. Calibrate the battery to stabilize the coconut on the ladder. By the way, there are some really idiotic comments on here, concerning rooting, better or worse battery life, etc. Geez people, read up on things before you make yourself look completely stupid. Google search is your friend. 5/5

Note to ppl you must have rooted phone! Before i got this, I'd charge to 100% and my cell would be at 98% before I could unlock my phone after unplugging it and would drop drastically as I used it, gaming was impossible without constant charging, this fixed it! I'm running lollipop gpe 5.0.1 ROM on a galaxy s4 i337m oh n i have my cpu idle uped too. 5 stars! 5/5

Ok so it saying my battery is charged 100% (4200mv which is what out said anyway before calibration) however when it reaches 0% I still have over 3500mv..so my battery is only using 600+mv for a full charge n is saying empty when its used around 20% of the juice..therefore I still have around 80% of my battery left but my fone still dies. Msged dev but no response.. 1/5

so sorry for my first bad review it is not your fault devs srry i did not rooted properly my device so sorry 5/5

One is always somewhat comprehensive but I was amazed that after observing my battery draining rapidly after upgrading the o/s I got to googling a bit and downloaded Battery Calibration and tried this app and heck it just does what it promised. Thanks Great App. 5/5

My battery wasnt lasting a whole day after I rooted my phone and put a new Rom on it. I followed the directions and its been almost 17 hours and i still have 68% battery life. Thank you Dev 5/5

This app does not calibrate the battery. It merely removes the batterystats.bin file which is just saved stats on your battery. It DOES NOT affect the life/uptime of your battery. Placebo effect. 2/5

i have unlocked xperia e and using cm 11 unofficial....i hate the way the battery quickly drain...after using this apps....my battery lifetime extend into 9 hr with 32%..... whenever i go its still 31-29....thumbs up (y) 5/5

who is low rating or reference the google stance on this shouldnt even be rooted because u nor google missed the whole point of this app. it never claimed to physically fix a battery u morons 5/5

This is good, this app is for root users only. Why would non-root users rate this as 1 star? If you are not rooted and this app is not compatible it is YOUR PROBLEM, why blame the app? Stay away from root apps losers. 5/5

To the people who are saying this gives you better battery life, that is impossible with this app. it just does what it says it will do 5/5

I mean, it does what it says it will do, I has absolutely no problem using it on my Samsung Galaxy S4 i9505, but before using it I would get 21 hours on 50% of my battery after installing CyanogenMod 10.2, but since I used this app I struggle to get 7 hours on the same amount of battery life. I don't understand why this is, but hopefully it's down to user error? 2/5

I upgraded cyanogenmod, and my battery starting draining at about 7% an hour at Idle. I installed this app, ran it, then did a full discharge and charge cycle, and now my battery works again! I left the phone idle for an hour, and it only lost 1% after running this app! Awesome! 5/5

I hated my battery life but loved my new Rom, used this app and Iove it! Must have after flashing, really makes a difference! Please don't rate badly if you use and are NOT rooted, for rooted device only! If you don't know what rooting is your NOT rooted. Great tool! 5/5

I'm not convinced this app helps. Battery percent after unplugging was dropping to 98% instantly, today it plummeted to 89%, on a new battery. :( 3/5

This app saved my marriage. My "battery" wasn't lasting over 2 mins b4 getting drained then I downloaded this app. Now my ahem "battery" last almost an hour a round. My spouse and 2 mistresses owe this dev a real debt. Thank u battery calibrator for calibrating my ahem "battery". 5/5

I have it installed and executed. But when it goes to 13% it shuts down my phone. Why? When I start up again u still can use it until it hits 1%. Any idea what could cause this? 1/5