Note7 Battery SWAP MOD? Note5 / S6 / S7E Battery etc ?

[Mr.Ultimate]

So as it seems the underlying issue was all in these batteries of note7 and the aggressive design of the phone chassis itself - leaving little to no gaps for battery, probably not enough space for battery front and back either so batteries easily got squashed inside of the super-slim factor phone design chassis while wearing phone in tight pocket like situations and due to the fragile nature of the battery it just got affected, damaged and caught on fire like explained in latest samsung reports.

Here is the deal, I will get equivalent original samsung battery from S7Edge model etc, same 3600mAh capacity (providing the thickness is same or less than that of Note7) and with necessary modification (if applicable) to the battery terminal flex connector so it clips right in to the Note7 PCB just like original Note7 battery did, I think this should be excellent workaround for dangerous Note7 batteries!

I of course would try to perform various tests before final assembly of the phone with new battery mod in it, such as full discharge and recharge, also recharge while heavily loading phone with benchmarks, and also attempt multiple fast charging routines monitor how phone behaves with the new battery, that is - all these tests are to be done on phone fully disassembled in the worst case scenario if phone battery still would get caught on fire during the testing I would at least salvage the phone from disaster that otherwise would be inevitable when testing phone fully assembled.

Your thoughts?

 

[Thevendren]

I would say you should give it a go. But isn't the S7 battery bigger ? How about trying to go with the S7 non edge battery instead ? Plus I thought that some battery were not soldered properly and made a short circuit to happen ?

Source I read : https://www.cnet.com/news/samsung-galaxy-note-7-return-exchange-faq/

 

[Mr.Ultimate]

Im yet to find out about the battery dimensions/size. while s7edge appears ~1mm thinner to my observation makes me think battery design should be similar or lesser in thickness and I really expect it to be no taller/wider but that is to be confirmed later when I take it apart(if it comes to that).

If batteries do fit, all I need to do is to unwrap the shield of the note7 battery where PCB is soldered to +/- terminals and replace battery connection pcb the same way back to s7e battery.
I think s7e battery would be the best candidate as for 3600mah capacity vs 3500mah note7 capacity, even if phone some way tries to charge this battery further than 3500mah as per physical capacity of the battery it should be "safe" I think.
Where if the battery installed would be ~3000mah etc, note7 battery terminal PCB chip would probably try to achieve 3500mah capacity and charge may again result in innevitable fatality, that is unless note7 battery pcb chip registers battery capacity 3000mah as wear and tear and adopts to charge only to 3000mah without actually overcharging it.
Had some hobby experience playing with iphone 4 4s 5s batteries in the past where I would swap around pcbs with batteries and phone would work, not ideal because I didnt pay much attention which went where but it did work to great extent.

I too see that the defects ratio was not definite and more so it was one in many many thousands that had bad soldering or manufacturing practice etc missing protective layers and so on, as I observe my note7 battery is always very cold never hot even cooler than that of s7 edge so I think analogy goes to be correct, but still I rather not take much chance with it if you know where Im going with this - "WHAT IF..."

 

[GarnetSunset]

Im yet to find out about the battery dimensions/size. while s7edge appears ~1mm thinner to my observation makes me think battery design should be similar or lesser in thickness and I really expect it to be no taller/wider but that is to be confirmed later when I take it apart(if it comes to that).

If batteries do fit, all I need to do is to unwrap the shield of the note7 battery where PCB is soldered to +/- terminals and replace battery connection pcb the same way back to s7e battery.
I think s7e battery would be the best candidate as for 3600mah capacity vs 3500mah note7 capacity, even if phone some way tries to charge this battery further than 3500mah as per physical capacity of the battery it should be "safe" I think.
Where if the battery installed would be ~3000mah etc, note7 battery terminal PCB chip would probably try to achieve 3500mah capacity and charge may again result in innevitable fatality, that is unless note7 battery pcb chip registers battery capacity 3000mah as wear and tear and adopts to charge only to 3000mah without actually overcharging it.
Had some hobby experience playing with iphone 4 4s 5s batteries in the past where I would swap around pcbs with batteries and phone would work, not ideal because I didnt pay much attention which went where but it did work to great extent.

I too see that the defects ratio was not definite and more so it was one in many many thousands that had bad soldering or manufacturing practice etc missing protective layers and so on, as I observe my note7 battery is always very cold never hot even cooler than that of s7 edge so I think analogy goes to be correct, but still I rather not take much chance with it if you know where Im going with this - "WHAT IF..."

So basically no chance eh?

 

[Mr.Ultimate]

So basically no chance eh?

Well, whatsup with that straight "face to the wall" so well thought trough pessimistic comment?

Do you not have life to live meantime?

 

[MrBaltazar]

It seems as if the flex cables are different and the note 7 battery is narrower.

I'm disappointed there hasn't been an aftermarket manufacturer that has created a "safe" battery replacement yet.

I'm using a Verizon Note 7 that I reflashed with AT&T firmware. Since the IMEI is not an AT&T IMEI, I haven't had to worry about "green battery" or "killswitch" updates coming to the phone. Still worried daily that my house will burn down or something, however.

 

[jopa7]

I think no company will provide an aftermarket battery because the market is very small. That eventually would happen if Samsung refurbished all Note7's and reintroduced them in the market. Mine (have 2) are working flawlessly without any issues

Sent from my SM-N930F using XDA-Developers Legacy app

 

[Mr.Ultimate]

Im not certain about sizes yet, it could be alot due to optical ilusion, as s7e and n7 are little different layout, etc - battery in the s7e is seated little further to the left (meaning more toward the center of the phone) and the camera on s7e at least to me from the first glance when compared to n7 looks more further to the right side which creates illusion of s7 battery to be wider because of its positioning. I may be completely wrong, just wanted to throw that in there though.

Also, battery from note4, S5 can potentially be used too, of course its core would need to be stripped and de-soldered from the old PCB and after that you have a naked battery pack that is still permanently safely sealed with two (positive and negative) terminals exposed ready for soldering with original note7 battery PCB and connection, providing we get enough room inside battery compartment. it all can be utilized, and even more, maybe note5, maybe s6 s6edge s6edge+ s7 and other similar sized samsung batteries of recent production years have similar measures that will make it a good potential donor? I'd say even if one can find battery of similar but not larger in size and capacity battery from any other manufacturer it should also work by the same methods of DIY, of course obviously acknowledging that the use of quick/fast-charge can be detrimental suicidal step in a way of charging the phone after any such DIY, even if it was samsung approved battery, fast charge is a fast-lane of premature battery wear/overheat and failure, such as explosions.

Here is my observations, I own few of these Note7. I have never ever once used fast charging on them knowing what it does and how it physically affects batteries, never ever had I used it on my note5 s6 s6e or s7e, I rather have my phone charge longer rather than let battery prematurely wear out sooner, and nobody knows what if S6 S7 batteries undergo the same quality testing like note7 batteries did and it was just a great matter of luck to a slight degree that not so many s6 s7's had exploded in the past due to quick charge technology used. Of course, alot of what I said is speculation, but just take that for a minute and let it sink in, think about it. Its certain - not everything that ever happens is publicized.

 

[Mr.Ultimate]

Ok, according to my research (call it bro-science) as it was internet based on official reported measurements of devices, I picked some stripped down samsung phones (notes and S series), adjusted these pics to represent real manufacturer reported dimensions in photoshop and measured batteries in the pictures. So far I can give rough estimates and the best to my knowledge these measures may not represent exact measures of the batteries but actual measures should be less or equal than what I have figured out. Only thing left to question is the thickness of the batteries:
We have here a patient, in a name of: Note7, this battery measures 99mm x 38.5mm
Other models I have looked at were:
S7edge 96mm x 41mm ( @MrBaltazar > you were correct regarding battery size there, its too wide )
S7 88mm x 37.5mm (looks like ideal candidate for now, especially providing extra headroom for DIY work on the top of the battery which may not come out as neat as from manufacturer)
S6 99.5mm x 46mm (too tall & too wide)
Note5 108mm x 42mm (too tall & too wide)
Note4 93mm x 39mm x 5.5mm(also seems like an ideal candidate plus its 220mah more in capacity vs S7 3000mah battery)
S7 Active 91mm x 40mm (this would be interesting @ 4000mAh ... I just am almost certain - thickness of this battery got to be greater than note7 or note4/s7 candidate battery... a strong guess)

I feel note4 may be real good choice if S7 battery thickness is more than that of Note7, and note4 battery turns out to be slimmer or the same thickness after being stripped as Note7 battery ... especially after removing the top plastic trim that holds gold plated battery terminals with battery pcb and unwrapping first layer of label with NFC antena, that should shave off additional ~0.2-0.5mm from the whole 5.5mm note4 battery thickness.

So thats that, some food for thought

 

[GarnetSunset]

Alright first off,

HOLY ****ING ****

Second off,

That's amazing

Third off,

**** you ;P

Keep up the good work mate! If you can find a system you can replicate let me know, I would LOVE to try it.

 

[Mr.Ultimate]

Im sure it will all work well, keep an eye out here, this actually drives me somewhat to do this. Most interesting is testing under load once all is done.

I was thinking more, and I believe S7 3000mAh battery is the best choice regardless of anything (unless S7 Active battery magically fits just the same, but its unlikely given its huge capacity it must be much thicker, but I am not sure 100% yet anyway). S7 and Note7 is of the same period/same production line, so if anything it should work the best, even with quick/fast charge when needed, as I thought today it still would be a very good feature to use if one is stuck in an emergency situation such as airport and needs a quick sufficient charge in short time - if fast charge works well - its there to use, otherwise I would still be against using it every-time, for longevity of course.

another interesting trick would be to remove Note7 battery and have it X-Rayed to see if any dangers are underlying like those explained by samsung, should be visible under high-res x-ray imaging, but I dont have access to that(yet) so I will still keep the note7 battery cell for a while until maybe I get access to such equipment.

 

[MrBaltazar]

Ok, according to my research (call it bro-science) as it was internet based on official reported measurements of devices, I picked some stripped down samsung phones (notes and S series), adjusted these pics to represent real manufacturer reported dimensions in photoshop and measured batteries in the pictures. So far I can give rough estimates and the best to my knowledge these measures may not represent exact measures of the batteries but actual measures should be less or equal than what I have figured out. Only thing left to question is the thickness of the batteries:
We have here a patient, in a name of: Note7, this battery measures 99mm x 38.5mm
Other models I have looked at were:
S7edge 96mm x 41mm ( @MrBaltazar > you were correct regarding battery size there, its too wide )
S7 88mm x 37.5mm (looks like ideal candidate for now, especially providing extra headroom for DIY work on the top of the battery which may not come out as neat as from manufacturer)
S6 99.5mm x 46mm (too tall & too wide)
Note5 108mm x 42mm (too tall & too wide)
Note4 93mm x 39mm x 5.5mm(also seems like an ideal candidate plus its 220mah more in capacity vs S7 3000mah battery)
S7 Active 91mm x 40mm (this would be interesting @ 4000mAh ... I just am almost certain - thickness of this battery got to be greater than note7 or note4/s7 candidate battery... a strong guess)

I feel note4 may be real good choice if S7 battery thickness is more than that of Note7, and note4 battery turns out to be slimmer or the same thickness after being stripped as Note7 battery ... especially after removing the top plastic trim that holds gold plated battery terminals with battery pcb and unwrapping first layer of label with NFC antena, that should shave off additional ~0.2-0.5mm from the whole 5.5mm note4 battery thickness.

So thats that, some food for thought

Sounds like the Note 4 battery might be the ticket. I'd be willing to try this out if I knew how to attach the note 7 flex cable to the note 4 battery, as well as disassemble both batteries.

---------- Post added at 10:07 AM ---------- Previous post was at 10:03 AM ----------

Im sure it will all work well, keep an eye out here, this actually drives me somewhat to do this. Most interesting is testing under load once all is done.

I was thinking more, and I believe S7 3000mAh battery is the best choice regardless of anything (unless S7 Active battery magically fits just the same, but its unlikely given its huge capacity it must be much thicker, but I am not sure 100% yet anyway). S7 and Note7 is of the same period/same production line, so if anything it should work the best, even with quick/fast charge when needed, as I thought today it still would be a very good feature to use if one is stuck in an emergency situation such as airport and needs a quick sufficient charge in short time - if fast charge works well - its there to use, otherwise I would still be against using it every-time, for longevity of course.

another interesting trick would be to remove Note7 battery and have it X-Rayed to see if any dangers are underlying like those explained by samsung, should be visible under high-res x-ray imaging, but I dont have access to that(yet) so I will still keep the note7 battery cell for a while until maybe I get access to such equipment.

Please keep us informed on your endeavors into battery exploration.

---------- Post added at 10:12 AM ---------- Previous post was at 10:07 AM ----------

I am actually almost tempted to order a s7 battery and see if the connection is the same on the note 7 PCB. Then it's just a matter of bending the flex cable into place

 

[Mr.Ultimate]

Connectors all look identical for S6 Note5 S7 S7E , what worries me most I think the most is its the way pinouts can vary on them model to model, as I remember there's not only Positive/negative terminals , look here:

other connections are also important, and most important that it is not going to get connected in reverse which I dont want to even try, thats too precious loss if I fry anything on note7 pcb, try go and get another one of those note7 pcb's nowadays ahaha, let alone note7's !

So, all in all we can try and measure terminal voltages on both Note7 vs S7 and compare how it looks on multimeter, then try position it accordingly and expect it to be straight fit, then if all works well and flex is actually long enough - solution is found, no need anything to solder I suppose just plug in, bend flex a lil bit where necesary, making sure no sharp edges are exposed to the bent flex, no excessive pressure applied on bent flex cable before/after assembly, and for most part that the battery is right thickness and not squished in there, then its all green-lights and good to go, but just by the visuals it looks that note 7 has somewhat longer flex, and oposite facing angle, look here:

S7:

Note7:

 

[Mr.Ultimate]

I did not realize it would be this difficult to find authentic original non-replica s7 battery... lots places sell those but if one has half functioning brain its clear as day these are non-original... However, I did find some note4 original in samsung retail packaging and all papers batteries, which I think rather go with, which is almost local too vs. importing another second best from China/Hong Kong... so that's that... My only hopes in buying note4 battery, if its truly original and new unused not charged unabused piece is that if it will still actually hold 3000+ mah capacity off the shelf ... hope it will. I mean after all it would be dormant for 2~3 years or more, and batteries do get old and sometimes just prematurely die also...

Will keep you posted

Night

 

[Mr.Ultimate]

Updates...

So far I was very unlucky sourcing S7 battery which is my personal preference option due to this battery being most "up to date" tech variant available that should logically fit vs. the second best choice - a Note4 battery...

Also my donor Note7 is due in tomorrow as best case scenario, or latest Monday-Tuesday the 19'th-20'th of February, and I just dont feel like burning 30bucks on battery that probably does not fit by its thickness... (talking about note4 battery) , so I really want to take apart this note7 first and inspect the thickness of its original battery and the depth of the phone. What I mean in detail by that - please review this in-depth detailed report:
https://www.instrumental.ai/blog/2016/12/beyond-the-teardown-galaxy-note-7

^^^ That is allegedly a note7 illustrated right there, this gives me hopes as if I stripped plastic and NFC chip from note4 battery I should end up with just about 5mm of thickness of the naked without NCF chip and w/o labels battery. However, I need to look harder about the S7 battery thickness as my eyesight would be strongly concentrated toward that if it was of the same thickness or even better if it was just under 5mm, but I am not sure...
I also contemplated maybe even retrofitting apple iphone 6/6s or 7 battery providing it fits by its dimension and voltage measures (yea just pulled it from thin air havent measured or researched yet) , but at least talking about voltages should be bout right and capacity may be close to that of S7...
Otherwise I was even thinking removing NFC/Wireless charging mechanisms from the enclosure so the excess pressure from battery wear and tear does not build up on either old original or new replacement retrofit batteries, give or take there has to be ~10% headroom for battery expansion which was really not thought trough in note7's (or if it was there was general battery design fault that was underestimated and exaggerated expectations from engineers who designed battery had failed them prematurely...)
I have meantime located S6 battery which is way too big and it by no means going to be fitted there but I have another few tests in mind until I get my properly fitting battery alternative, just to rule out some questions and variables...

I think Chinese market fellows are up to some news regards note 7 because just lately I have noticed increase spike of note 7 cases and accessories at least on ebay, it just spiked my curiosity, what are the plans of samsung for the remaining 3+million note7's that they got back from the recall, are they by slight chance gonna push Note7S with note8 and S8 release? what are the chances of that happening?

Also I was deeply considering how would note4 battery be of a worse technology build vs S7 battery, knowing everyone who I know had note4 in the past almost every single one of them batteries had expended and died out rather soon within first year or so... I am just very cautious about this happening prematurely while retrofitted in note7 ... where as with S7 as many people I know using them and it has been about a year now of heavy use and abuse including those using quick-charge, batteries still perform ok and not swelling which is more promising when compared to note4 battery.

As lucky as I can get just by doing online hunt, I found one seller on aliexpress selling copy replacement batteries where he claims battery measurements to be ~88mm x 40mm x 5mm, and here we are talking about non original battery that is rated @ 3300mah as per sellers web page , out of which I feel it is reasonable to believe that it holds quality ~2000mah capacity knowing how all these generic batteries are made... it is real hard to find genuine battery, unless if I want to wait 60 days, I can order from China... hard hard decision on waiting vs the availability. I really am leaning forward just straight S7 battery swap with best hopes of longevity , but the quest now is to get exact measurements and fast delivery.

PS: Anybody reading this has new original battery for S7 (SM-G930 / G9300)who can ship it over to me or measure it precisely X * Y * Z ?

Thanks

 

[manu_b]

I Tried Note 5 battery. Its bigger in terms of Length and width. As mentioned before flex cable is different and male/female end of connectors have been interchanged.
Out of desperation disassembled old battery and took the battery circuit out. Soldered Nokia BL-4C 3.7 V 840mah battery. Voltage of battery at full charge ~4.1V. Charging stops at 100%. I was thinking of installing something like old rom to limit charge to 60%. I will be installing wireless charging battery for the battery backup.
Its quite fun to play with it.

http://ca.crackberry.com/samsung-wireless-charging-backpack/4A123A24419.htm

 

[Mr.Ultimate]

I Tried Note 5 battery. Its bigger in terms of Length and width. As mentioned before flex cable is different and male/female end of connectors have been interchanged.
Out of desperation disassembled old battery and took the battery circuit out. Soldered Nokia BL-4C 3.7 V 840mah battery. Voltage of battery at full charge ~4.1V. Charging stops at 100%. I was thinking of installing something like old rom to limit charge to 60%. I will be installing wireless charging battery for the battery backup.
Its quite fun to play with it.

http://ca.crackberry.com/samsung-wireless-charging-backpack/4A123A24419.htm

Nice post, looks like you did not strip nokia battery from the nokia battery charging PCB so it literally goes two ways. I may be wrong but I believe I am not, when battery wears out on original samsung battery combination, lets say samsung s7 battery was used and abused and from 3000mah drops to ~1700mah real usable capacity, the charging chip adjusts accordingly to the current usable capacity and stops charging when receives signaling from the battery that it no longer increases in the charge capacity. Hope Im putting it out right so you can understand, I believe if you use note7 charging pcb chip on stripped nokia 800mah battery it should literally accept 800mah as total max capacity and record this "100% equivalent" memory record in to its circuit (dont know if its one way memory write though , because as if you were to add 3000mah s7 battery on the later date, the N7 battery charging pcb chip may decide only charge it to 800mah due to previous record of capacity created when 800mah battery was used...)

Its complicated I know... but thats what I would do. Otherwise, two nokia batteries if stripped could be coupled parallel (if it fits well) and you therefore have 1600mah battery) which is rather usable for at least ~ half a day off the power cable

I was also thinking about note7 wireless battery charger mod, I dont know whats inside of that battery back pack, but if there is enough space to store two S7 or S7edge batteries, that would be amazing DIY mod that would deliver ~9000-10000mah of raw juice coupled with S7 battery already installed in the N7 frame.

For most I hope tha note7 battery charging chip does not have memory recording feature on its own, so we can play with random batteries for as long as we find one working the best, as otherwise if it does have such effect - its sad news, as once you install less than 3000mah S7 battery for testing etc, you can never use 3000mah brand new batery to its full capacity, but I am only speculating here for the most part untill its tried.

While on this note - would you have another of the same type nokia battery to connect in parallel (doubling the capacity) to see if it still charges to 100% on indicator and last ~twice as long after this mod?

PS: I think time to time n7 backpack battery cases appear online on ebay for lots cheaper, worth a search there too

Also, the charging indicator @100% is fine and well, and setting limitation of charge to 60% in settings would result in 60% of currently measured capacity which I believe is pretty pointless as that was the aim of samsung safety/prevention methods, knowing batteries usually failed while in higher charge state - they tend to swell more and tight fitment inside the n7 prevents expansion therefore battery will be softly pushing against itself while theres a risk of failure at that shorting within itself due to built up inner pressure, thats why the limiting to 80% then 60% then 30% was put in place so batteries does not reach high charge state there fore does not expand as much within itself and the risks are greatly reduced, that's how I understand samsungs point of view on the issue.

Let me know what do you think

 

[Mr.Ultimate]

now that looks interesting ... https://www.xda-developers.com/repo...rbished-galaxy-note-7-with-a-smaller-battery/

replacing old chassis with thicker one to accommodate 3200mah battery? oh samsung

 

[GarnetSunset]

now that looks interesting ... https://www.xda-developers.com/repo...rbished-galaxy-note-7-with-a-smaller-battery/

replacing old chassis with thicker one to accommodate 3200mah battery? oh samsung

Please please please let me know if you have any success. And if so, please send me a link to a battery I can buy (S7) so I can attempt this too

 

[Mr.Ultimate]

Please please please let me know if you have any success. And if so, please send me a link to a battery I can buy (S7) so I can attempt this too

Hey I was just typing a reply to this thread and have seen you reply to it before I clicked [Submit Reply] ...
Ok, so Im in a "triangle" situation here right now... yes I had more of them note7 on hand but now... I have only two coral blue note 7's, one is new and unused but still it is unsealed box unmodified/unupdated unit which works perfect and charges to a 100% battery etc which I intend to keep this way for later on selling it for a profit probably to some enthusiast collectioner guy...and another coral blue note7 is as good as new but it is used for few weeks by the first owner and it had this deadly update from samsung that prevented it from charging, so I have fixed this and now it is charging while still on its latest firmware and I am willing to play a little more with its firmware and so on until I decide to sell it too ... yeah I cant explain, I just enjoy reaching for some "goals", hitting them hard and then letting them go for someone else to enjoy while myself moving on, maybe weird, I know., but stay with me here for a moment. So I was thinking long and hard, and I am unable to justify splitting open my last firmware-fixed note7 that I was so anticipating on doing so ... that waterproof seal from factory means alot to me, I'd rather keep it on the phone for as long as I can, unless that would be inevitable, as I originally imagined the last note7 unit with disabled battery charging would require me to split it open to do at least battery charging up outside the phone just to get it ON so I could work on it trying to patch firmware and do some battery experiments further while Im at it, but as you may know I managed to fix it without opening it... and I few days ago (again...) I ordered myself another one of these bad boys Note7's, but this time its for real guys, its a cheap live demo unit (LDU), it should have no IMEI/no GSM radio chip and otherwise to be identical to retail units, so this is the model I will be stripping apart, most definitely, promise. Meanwhile I am really seriously thinking about learning on rom modding so I can build at least one or few fresh Note7 rom's for folks that are still out there holding on tight and giving all the love and care for their old note7's. The only one real reason is holding me back from keeping and using one of two note7 straight away and modifying it for self use is that I cannot get my hands on any dual sim note7 model (SM-N9300 or SM-N930FD), which I adore to death, literally... as my daily driver of a phone is S7edgde DUOS at the moment and it is a life saver not needing me to carry two phones everywhere I go, and any of note7's I had would make me do just that, use 2nd phone which is really not ideal at all... however dilemma in my mind goes to expect me to finally modify and use one of the two blue note7's if I will not be able to sell it for minimal no-loss profit, but for now I do not the plan on using any of them for daily use, hence my reasoning on waiting till I get Note7 LDU some time next week and give it all my tech-modifying love so I can break the IP68 water sealed back loose, probably crack it or scratch it and not be bothered about the rough love and abuse because Im about to give it, as this LDU has no such value as any of other retail units that I have... hope you's understand where Im coming from and are patient enough not to cross me over yet and wait a little more for my experiments on battery mods.

On another thought, since samsung-pay will not work and I am not sure if android pay will have any use with such heavily modified note7, I was really thinking taking out NFC/Wireless charging modules from the inside of the back of note7 to get more headroom for battery swap, plus if opportunity allows, I may as well split the chassis from the LCD screen later (if its feasible option) and measure the firewall thickness between the amoled screen and battery, see how much more I could machine off of that firewall while keeping some minimal amount of it still there for screen protection purposes, just a thought in an open wild triggered by the last samsung report regarding refurbed note7's which will receive thicker chassis, which may be ~2mm extra in thickness etc...