iPhone Double Battery Life Mod

Hi I am an engineering student at OSU and wanted more battery life while studying and pulling all nighters on my iPhone 4. So I added a second battery!

I had to fab a new back for the phone but the upside is the back it now aluminum and doesn't need a back cover, just maybe a bumper so it is smaller than if it had an otter box. Here is the final product! It looks a little jankey but I did make it with a dremel, a file, a hammer, and some stong epoxy. Let me know if you have questions or would like me to make one for you! It is fully reversible for warranties as well. It gets about twice the battery life as the original. Enjoy!

Edit: The start of version two are the last two!

Mars478 said:

Legend! Can you show us the inside?

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I have a lot of homework for tonight but what the heck! i'll shoot one up here. brb

Here you go! I wanted to shrink rap the inside but I was a little too excited.

3bs said:

Impressive that you did that all by yourself.

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Thanks man! I have done cooler stuff, just nothing with a device that half of the people in the world own! haha

Kyotoma said:

That's a great proof of concept. Now I wonder: could you do it with a same form-factor but with a single unit? I realize that you'd probably then have to develop a custom battery for this but hey, one can dream.

Go Buckeyes! Haha. I'll be down in Columbus next month for Rock on the Range.

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Haha! Sweet! Go Bucks!

I was thinking about the same back glass with just a spacer and making the back not be conformed to the 2nd battery. It would just be a little thicker but then wider (higher capacity) battery of the same thickness would probobly be able to take up the empty space for more than double the battery life of the original. I wish someone would sell a battery + back cover kit since there are so many replacements already.

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Mars478 said:

So you just stacked two batteries together and soldered them into parallel? How's the battery life looking?

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That is pretty much it! haha It is almost exacltly twice as long as the original. I got ~23 hours of video until it was at 5%.

I am also modding my old case to accept the mod as well and will put up pictures when I am all done. Thanks for looking.