Battery mod question. - Android Q&A, Help & Troubleshooting

Hello XDA,
I have an iphone 4s of which the battery swelled. cut the circuit of the cell, threw out the battery, and confirmed that the phone works. Now, I have several extra batteries, and wanted to wire one to the phone. I would wire them to the original battery connector, and it should just click into the factory place and work.
This phone is a test/experiment/I-couldn't-care-less-for-it phone, so the battery would be taped to the back. (my OP3 is my daily driver)
The iPhone has 4 pins, and the only 4 pin battery I have is an aftermarket Galaxy S4 battery.
(2100 mAh F5 3.7v)
My question is this, is there any reason that it will not work, if I connect the 4 pins pin to pin?
According to my knowledge, both the iPhone and Samsung battery are 3.7v, and the the mAh is just the capacity. The thermistor and data pins should detect battery charge and discharge, and the motherboard would adjust to the battery. My logic with this mod is that if the double sized batteries that fit and work on your phone from ebay work, why can't I strap a bigger(bigger in mAh + physical size, but same output-3.7v) battery to the back.
I've done this before on a clone
HTML:
http://imgur.com/a/ls5Ul
and the battery held for a week with WiFi and Bluetooth on!
I've been googling a lot, and could not find a lot of information as to why this would not work. I've found one worrying link saying that the bigger the mAh of the battery, the larger the Ohm resistance. Is this true? Would a bigger mAh battery fry the phone? I thought mAh was just the capacity in amper hours, not the discharge rate(3.7v?!).
Any info will help a lot, thanks!
-iPhone 4s 16GB
edit:
Would I be able to use a 3 pin battery thus leaving one pin empty?
If I was to use a 3 pin battery, to which pins would I connect them?

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ACFH said:
A 4 pins battery has 2 power pin, 1 metter pin, 1 data pin. Data pin is some kind battery ID. Most phone dont work if you using another manufacture battery (wrong ID). You better take out battery cell and solder to origin battery board. It work for me (I'm not try with ip yet).
Click to expand...
Click to collapse
I thought of this too, but could it be that the battery swelled because of a bad battery board?

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Would anyone know which is the positive and negative side on the circuit?(not the battery) There is a small "1" and "2" next to each terminal, but I don't know which is what.
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