new to batteries

[Dom]

Im looking to buy one of the istick 100's. on my freedom smokes they suggest two different batteries.
Samsung INR 18650-25R 2500mAh Battery and the Sony VTC4 18650-30R 2100mAh Battery w/ Flat Top. Not sure what the flat top is for and not sure what the 25 r and 30 r means. should i go with the higher "mAh" or "R"?

 

[Eitje]

(9) Battery Basics for Mods; the Ultimate Battery Guide | E-Cigarette Forum

Might help you along, bit of a read and can check more of his blogs.
Both are good batteries by the way.

I think the Sony's are rated a bit higher on continuous discharge but since your iStick is a dual battery device with batteries in parallel, you should be covered with the Samsung's just the same.

 

[Mooch]

With only 50W per battery you can go with the 3000mAh LG HG2 battery and enjoy the longer time before needing to recharge. Otherwise, the Samsung 25R will be fine.

I second @Eitje's recommendation, read @Baditude's blog. Some great information there.