Samsung 4200mAh battery mod

this is a mod for using two OEM Samsung batteries together for a "real" 4200mAh extended battery. unlike most 3rd party batteries the OEM ones tend to be much closer to their rated tolerance voltages and mAh.

this thing is a BEAST!

DIY:

i am not responsible for any bad stuff that happens to you or your phone. im not right in the head, i have a modding sickness and i do crazy stuff to expencive things i have only owned for a few days. so folowing this DIY means your crazy too and dont care if your phone blows up in your pocket or whatever...

if you have never soldered anything before. just stop now... dont do this mod.

if you bridge the wrong contacts with solder your battery WILL catch on fire, melt and possibly explode. this is not a joke!

please dont post questions about asking how to solder etc. i will flat out ignore them as i dont want you to do this mod if you dont have exp in this dept.

also make sure BOTH batteries are charged up to at least 4.3v before even starting.

for ref:

battery 1 is the one closest to the phone
battery 2 is the one with NFC and furthest away from the phone

now for the directions...

if you dont care about NFC and just want the battery to work ignore everything below. just tape the batteries together and just solder the + & - contacts in parallel. bam! your done. :good:

for working NFC: :fingers-crossed:

1. remove silver outer sticker from both batteries & remove the NFC sticker from only battery 1 (not sure if removing the NFC sticker is 100% necessary but its what i did). then take the little black end caps with the water mark stickers off. you can just pry them off pretty easily.



2. tin the following contacts on each battery.



3. tape off the following contacts on battery 1 only.



4. use a tiny bit of double sided tape to join the two batteries together. dont use too much tho, just in case you ever need to take them apart later. make sure the batteries are positioned correctly. you want battery 2 (with NFC) on the out side.



5. use foil tape or copper tape to go over top of the tape you already put on battery 1and solder it to the parallel contacts on battery 2.

what your doing here is just telling the circuit to ignore battery 1's passive contacts for NFC and jump the circuit to battery 2 to power the NFC sticker.





6. now solder the following contacts.




7. tape the two batteries together so if you need to pull the battery the whole assembly will come out in one piece.



8. tape off the exposed contacts just for safety sake.

first 8hrs off the charger

no power saving stuff. no wifi, 2hrs of Pandora over Bluetooth.

To be honest i don't use NFC. I don't even know what I can test it on.

i did intend to have it work thats why i disconnected the NFC on one of the batteries. i didnt want it to get confused . lol

end of first cycle:

moderate use over long day.... slept for 4 hrs (you can see it flatten out near the end) then i hit things pretty hard with web browsing for the last stretch.

about 1 hr of Power Amp, 2 hrs of pandora. 30min GPS. 30min of games, a bunch of random youtube searches in HD. always on 4G

no wifi, everything else on. no power saving. auto brightness.


this cycle didnt really sown the battries true colors. but after this cycle the calabration was much better and it shows in the following posts.

ranchosteve said:

Any update in your battery?

Would be possible to use a generic extended battery housing and swap out the battery's with Samsung ones?

Sent from my SPH-L710 using xda premium

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nope. at least not with my Max power ones. i was going to try to use the same charging circuit board off the Max power batts but the samsung cells are bigger and dont fit inside the non-OEM case underneath the stickers.

however the battery door from my Max power batts does fit the phone with the modded Samsung 4200mAh if thats what your asking?

i actually haven't gone thru any full discharges other than the ones i posted due to a really busy work schedule. but i will update ASAP.

update:

25hrs off the charger. 3hrs screen time, played N64 emu for about 45min, poweramp for 2hrs, pandora for 1.5hrs, 30min of web browsing, 45 min of voice calls, etc...

all radios on except WiFi. been on 4G this whole time. no power saving, auto brightness.


still got 41% left.

need to figure out what "Media server" is and why its taken more power than my browser...

Sweet, thanks.

Currently @ 6% and over 7hrs screen time. Ill prob be able to squeeze 36hrs out of thisbattery with no compromise on my usage. On heavy use days (more web and screen time) I'd surly be able to get a full 16-18 hrs of use.

Ill post screen shots when i get down to 1-2%

G1_enthusiast said:

U need to post an extensive guide on how to do this.

Sent from my SGH-T999 using xda premium

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Click to collapse

i will but im pretty sure NFC is not working right now. ill have to do some crazy soldering tricks to get it working. worst part is that it all will be off theory. as i still cant find a schematic.

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Update:

i had it down to 4% and then i had to use my GPS for a longer period of time than the batt would last so to avoid taking screen shots and rebooting during my trip i had to just put it on the charger. but here are the screen shots. im pretty happy with the results.

mind you i would not consider this "heavy use" for my normal day to day. but the idea is accomplished. i have a battery that can last me 1 full day now matter how hard i beat on it. :victory:

all radios on (except WiFi) always on 4G, no power saving, auto brightness.

5hrs of pandora

3hrs of PowerAmp

1hr of N64oid

7hrs screen time

45min voice calls