The link I posted has all the data you need. Charging and discharging currents are listed.

I recommend these Samsung 25r's

Health Store and More. Theyre actually the #1 Best Seller in 3.7v batteries, you believe that? I ordered from here earlier and these were just fine.

Also, I found it kind of odd that Health Store said they sold assorted colors blue and green.

3s and 12 parallel ?

Yup, so that's 36 batteries. One battery costs $7, so a whole pack will be $250, just what you'd pay for an already assembled pack on Amazon.

Add casing, voltage regulator, spot welding and you'll see that they cost so much money for a reason.