Galaxy S6 battery mod: S7 Edge battery

I am pretty happy with my Galaxy S6 – its an excellent phone. Amazing CPU and GPU performance, fast storage (though I only got the 32 GB version), good software support (Samsung updated it to Nougat) and of course the beautiful AMOLED 1440p display – it certainly is one of the best phones released by Samsung. One issue I had with it, however was its battery life. At the beginning, while not amazing, the battery performance was okay – I was getting about 30 h with medium-heavy usage, which fast charging alleviated a lot. However, with using fast charging all the time, after an year and a half, my average battery life has dropped to about 18 hours, which while manageable is far from perfect.

So replacing the battery on the S6 is no easy task – as is with most phones manufactured recently – the days, where you could pop the back open and change it are gone and you have to do some pretty complicated stuff to get to that battery.

What you need?

In order to replace the battery on the Galaxy S6, you will need the following stuff:

  • hot air gun (hairdryer probably will work as well)
  • a suction cup
  • screwdriver set (for 3.5 mm Philips #00 screws)
  • hot silicon gun
  • S7 Edge battery (obviously)
  • a toothpick or another thin hard object
  • a thin hard plastic tool

Why S7 Edge battery?

Battery capacity comparison:

  • S6 – 2550 mAh
  • S6 Edge – 2600 mAh
  • S7 – 3000 mAh
  • S7 Edge – 3600 mAh

So it seems that the S7 battery is identical in dimensions with the S6 one and the S7 Edge battery is only slightly thicker and has much more capacity. This means that the S7 is easy replacement and with some luck we will be able to squeeze the larger S7 Edge battery in the S6 body… yeah – nothing dangerous about that. Not like Samsung got in any trouble attempting to push a large battery into a thin phone body…

Do this with care and on your own responsibility.

So armed with a lot of bravery and optimism let’s proceed to the actual work.

Opening the phone

I used this excellent video from WitRigs that covers the S6 battery replacement process very quick and thorough, so you can check it out, before proceeding to get a visual idea of what follows.

Before you begin, remove the sim card tray (here you use the toothpick/needle).

We will need to heat the back of the phone, in order to loosen the adhesive that holds it in place. While the electronics are pretty safe – after all they are made to be soldered, some of the other components like the screen and the battery may be damaged, in case of excessive heat. Note however that the adhesive that holds the back is really, really strong and you will need to both heat it up a lot and pull it very hard to separate it from the midframe.

 

So, first begin by heating the phone with the hot air gun. Make sure that you get it really hot, so the adhesive can loosen, but proceed carefully and slowly so you don’t burn something (like your hands).

Put the suction cup to the back of the phone and pull gently but firmly. Apply more force and/or heat, until you notice a thin split between the back cover and the midframe.

Insert your plastic tool there and slide it across the edges of the cover to break the adhesive from it. If it becomes too hard – don’t push it too much and reheat as needed. Take care, because the glass material, the back is made of, is bendy, but still cracks much easier than plastic.

After you break the adhesive tape from all sides, separate the cover and put it aside.

Removing the old battery

The black thing covering the battery is the NFC antenna / wireless charging. Peel its sides off the midframe to allow easier access to the battery.

There are 13 x 3.5 mm Philips #00 screws that hold the midframe to the mainboard and display assembly. Unscrew those and make sure to not lose them.

While holding the midframe from the sides with one hand,  push on the battery with the other. Apply force until the mainboard and display assembly “pops” out of the midframe.

Now remove the cable that connects the battery to the mainboard and proceed to take it off.

The battery is held to the front of the phone with a similar adhesive, so you will need to insert something hard and plastic to pop it out. Reheat if necessary.

Note: Puncturing the battery can cause the lithium inside to ignite or even explode! Do not use metal tools to separate it and be very careful!

Now we see here that the both batteries have very similar dimensions, the S7 Edge one is even a bit narrower.

However, it seems just a tiny bit thicker than the S6 one. (S6 on the left, S7 Edge on right)

Putting the new one in

Lets put it in the place of the original one and connect it to the mainboard. Take note that the connection cable is a bit longer, so you will need to bend it.

The new battery should sit well in the phone.

Let’s proceed to put the mainboard display assembly back in the midframe. Make sure that you begin screwing from opposite sides and not sequentially in order to avoid stressing the screw threads and assure that everything gets back in place.

I think that the thickness difference between the original S6 battery and the S7 Edge one is about 1 mm, so it is definitely a feasible mod.

Closing and sealing the phone

Now heat up the silicon gun and apply small amount all over the edges of the midframe.

Putting too much can make a mess after pressing it together, so just spread it over the edge.

On the right side, where the battery would protrude a bit, I decided to put a bit more silicon to make sure that any gap is not just air, but at least filled with silicon.

I also applied a bit more on the edges.

Be steady and slow – don’t rush it. The first silicon, you put, will most certainly cool down, until you finish putting the last. So take your time and apply it carefully. After it is done, align the back cover and put it on the silicon, you just laid. Fire the heat gun and melt that silicon back.

Press the back firmly until it pushes the silicon from the inside. Hold with your fingers on as many contact points as you can, until it has cooled down and solidified. Now, while it is still warm and soft, take a sharp plastic tool and slide over the edge where the silicon has came out, to gather the excess.

Now, you have it! The phone is put back together.

Don’t forget to put the SIM back.

After this mod, my phone had a very tiny opening on the right side between the back and the midframe, but since I had put a bit more silicon, I think its okay.

We turn it back on and… it works!

I am now charging it to 100%, after which I will calibrate the battery (to reset the battery stats). For this I recommend  the Battery Calibration [ROOT] app.

After I use if for a couple of days I will update this post with some battery life statistics.

UPDATE 05/01/2017:
Here are some statistics about my battery life after the mod.

  • Taha SEVER

    Hi; i was thinking about this mod. But you did it. How did you resolve capasity usage isue. İ think kernels will charge the battery till 2550 mah.

    • Well, the thing about battery percentage indicator in Android is that it is calculated from an algorithm modelling a lithium battery using only voltage reading as input. So while the mAh capacity of a battery is greater (like S7 Edge over S6) the operating voltage range is similar, because it is defined as 0% (voltage so low, that current is increasing dangerously and electronic circuits malfunction) to 100% (so high voltage that no point in trying to charge more), which is very similar across different smartphones / batteries. So while the endpoints may be very close, the voltage/capacity curve accuracy might depend on many other battery attributes like internal resistance and some other unique properties. Basically I am seeing roughly 70% increase in battery life, which accounts for the 41% increase from the original battery capacity (3600 / 2550) and the degradation of the old battery.

      I haven’t had enough days of typical usage (100 to 0, using moderate SoT) to make concrete conclusions yet, but I will definitely update the article, once I have.

      • Taha SEVER

        Thanks for reply. I am waiting for your sharings and aldo new battery to come 🙂

    • Merwan DJELLAB

      change value in system/etc/floating_feature.xml from
      2550 mAh
      to
      3600 mAh

      • Is that used for anything? It looks like a text data, not numeric capacity.

  • Patrick Wagner

    Hi, is this “Silicon Glue” in a heatgun or just a normal hotglue-gun ? Because i want to do this mod on my s6 and bought already the battery and repair tools
    Thank you

    • Well, I think I have exactly what Americans call “hot glue gun”. I hope that helps. 🙂

      • Patrick Wagner

        Yeah nice that helps, im very excited to do this 😀 , the s7 edge battery is awesome with its 3600mah !

  • Patrick Wagner

    After I had installed the battery the smartphone does not start any longer without charging cable.
    In the ROM menu the battery indicator remains at 86 to 88%, at about 4350mv. As soon as I remove the charging cable while the device is running the phone switches off. Any Ideas ? Thank you very much 🙂 (btw, was running everything “stock” rom kernel no root, maybe thats it ?)

    • Did you already sealed the back? Can you try if the phone behaves similarly when the battery is totally disconnected? If so then this means the problem is in the connection cable, but I guess you already tried fiddling with it. If not… then my best guess would be a faulty battery. Where did you get it from?

      • Patrick Wagner

        Have bought the battery of ebay “janado-shop”. It was also more expensive than the cheapest batteries. 18 euros paid. Had not expected such a problem and therefore the backcover already sealed :-/

        i can try it again to reconnect the connection-cable, maybe its too much bended. Just have to melt the glue again … the seal is actually very good had spend a lot of my time to do it properly 😀 . Well – **** happens 🙂

        • Yeah, I had previous bad experience when not testing another phone while it was still not sealed, so now I am always verifying twice before I close the phone. 🙂
          Btw, I would advise against ebay as a place to buy phone batteries – at least I did not have luck. If the problems turns out to come from faulty battery – check some local shop which sells legit OEM batteries.

          • Patrick Wagner

            Fixed it. (happy :D) the problem was the battery-connection-cable as you said
            i now start to calibrate the battery

          • Sibo Lin

            Hi Patrick,

            I have the exact same problem as you described above. I’ve tried playing around with the connection cable and reinstalling the s7e battery several times, to no avail. Do you have any tips for what was the key to getting it to work?

        • Is this your battery (http://www.ebay.de/itm/Original-Samsung-Akku-Batterie-EB-BG935ABE-3600-mAh-fuer-Galaxy-S7-EDGE-G935F-/282243846427 ). If so it seems ok, so maybe the connector is loose.

          • Patrick Wagner

            yes it is exactly this one, i try to fix the problem soon and reply my results, hope the internal battery-connection cable is not broken or something like that :p

  • Christophe BISCOVE

    Hi, I just received today the S7 edge battery from Ifixit and the repair kit.
    I just notice after that the battery is not branded Samsung. I sent a email to Ifixit to know why as I received something different from what they show.

    Anyway, I change the battery in my S6 and I notice that the new battery has the same thickness than the S6 battery. That meens I was able to use the original tape to close the back cover.
    Now everything is in place and the phone is in charge. I’ll let you know if everything is ok, later and give you the answer from ifixit.

    Ciaoo

    • Christophe BISCOVE

      Hi, I confirm that the battery from ifixit are fake. Just a new unbranded s6 with 2350mah, nothing more. If I cannot trust Ifixit where are we going ?
      Vordhosbn, where did you buy your’s ?

      Thanks

      • Taha SEVER

        Actually i bought battery from reatil Samsung Service Provider. It was a bit more expensive but it is originality guarenteed. I am using battery for a week and befer replacement i had to charge the phone twice a day for heavy usage and now i ade 2 days with single charge. But this time ı am getting overheating isue on heavy usage Like Google Navi, Blouetooth connected car and spotify music listening over lte at the same time. In this condititon ı am getting a full dayy battery life but after 3 hours of usage ı am getting over heating warning on phone screen and when i check it, it felt really hot. I checked the battery temp at this time, it showed 49.5C .

        FYI

      • @christophebiscove:disqus , I bought mine from a local bulgarian spare parts retailer – there was a cheap option for “compatible” battery and a bit more expensive for an OEM one. How do you know that the battery is fake? What kind of battery life do you experience?
        Maybe you can post a photo of the battery, so others can know what kind of battery not to buy.
        @tahasever:disqus , I have exactly the same use case – Google Maps navigation + Spotify over LTE + charging and the phone definitely gets warmer, but its not “hot” and I have not seen a temperature warning. What kind of ROM are you using?

        • Taha SEVER

          @borislazarov:disqus ;i am using custom rom from xda and N0G33K V2 kernel with synaps for some settings. i did not have other roms for testing but i will try on fture

  • Leandro Nunes

    Hello, just done the mod yesterday with s7 edge battery, but seems like stock, what could be wrong ? Calibration done at 100% .

    • Did you wait until the battery has discharged completely? Because it may seem to go down fairly fast, but then it will usually “stick” to 1% and stay there for hours. You will need to drain it completely until the phone shuts down and then recharge it to 100%. Then, after several such cycles, the percentage indicator becomes correct. The total lifetime of the battery however should not be affected by this, so you should see definite improvements – if you don’t then maybe its not genuine S7 Edge battery or has something wrong with it.

      • Leandro Nunes

        Yes, i have drain completely completely and recharge it to 100%, I will wait a few cycles to see improvements. the battery seems genuine, but really dont know…

      • Patrick Wagner

        My battery is still not calibrated too, did the full charge and discharge like 8 times now, charge until its green led, discharge until the phone shut down itself

        after dropping to 1%, there is still huge power left 😀

        Well, i use stock rom- u said something about you are using s7 note port noble rom ? maybe it has something to do with that i dont know :/

  • Fernando Gava

    Boa tarde amigo, gostaria de saber mais resultados da troca da bateria, também trabalho em assistencia técnica e estou pensando em trocar a bateria do meu s6 flat. obrigado

  • Maris Laudams

    If you take off sticker from battery will it be enough to close back properly? 😎

    • Hahah, I don’t think so. 😀
      I’ve read on xda, some people are removing the wireless charger coil-sticker thingy, but I really see it as pointless. Just make sure to seal the back in some way – hot silicon, thick double sided tape – whatever. I had bad experience in the past with adhesive tape on another phone and that’s why I used silicon for this replacement – it’s a bit messy, but it gets the job done.
      And generally speaking, I would advise against tampering with the structural integrity of the battery in any way.

    • Taha SEVER

      do you have any pics about this situation.

      İ removed nfcpad, and i got much better rear cover closeup result before than.

      • Maris Laudams

        I’m not sure to do or not to do. I don’t like idea about cover sticking out.
        As I’m using Android pay daily, I need nfc so I need other option.
        Battery is only thing I hate about this phone. Would be nice to extend it but would like to do it without visible ‘evidence’

      • But the nfc pad is paperthin. Its literally under half a millimeter. I just don’t see how removing it will gain any significant space. Are you certain that it was the removal of the charging pad that made the back close better?

        • Taha SEVER

          Yes its thin. But it works. If you look at the back side of the phone it seems complately closed. Left side of cover complately sits well. Right side which is battery side it sits with some presure but not much as left side.

  • Trung Đức

    Hi, i want ask about S6Edge can mod battery S7E ??

    • No, the S6 Edge battery has the power connector on the other side of the battery and it will not be easy replacement as with S6.

  • Peter Petrov

    Hey! I saw that this phone is running on Vivacom, which leads me to the conclusion that you’re in Bulgaria…Can I ask…How much will it cost me if I send my phone to you so you can change the battery 😀 I’m afraid I’ll break something 😐

  • Grarg

    In the pic where you remove the old battery, it looks like there is a raised edge running around the battery compartment that is separate from the rest. is this something that could possibly be removed to gain some extra room, making the back casing fit better?

    Would have been nice if someone made a third party cover wit an extra mm clearing that would fit snugly. 3D scanning the existing one and edit the resulting model to add a measly mm of height shouldn’t be too hard, but I’m more skeptical if it could be 3D printed thin enough in plastic and still offer any protection.

    • Well, I am pretty sure that this raised edge is there for a reason. If I were to speculate – it’s probably to accommodate for battery expansion/contraction, so removing it wouldn’t be ideal.

  • Dibyanshu Sharma

    how its working now??