I have 1 battery type Li-ion 18650 and its 1200mah - 3.7v and i have 1 ir led here is the datasheet of it:
https://pdf1.alldatasheet.com/datasheet-pdf/view/635258/OPTOSUPPLY/OSI3XNE3E1E.html

Btw:the maximum volt of the battery is 4.2v maybe "when full charged" and when i made the circuit its was not fully charged so its read 3.99v

So the datasheet above say the maximum voltage of the led is 2v at 700ma and the typical is 1.7 at 700ma 

[![ circuit ][1]][1]

Now first :every time i measure the ampere of the circuit the ampere is always under 100ma 
Before i said the second point i cant get the current of the led that he can take it beacuse on the datasheet its written 700ma and when i link it its say something under 100ma so i was confused and all i did is get some resistors and put it from the highest to the lowest to get the resistance i need
Second :i put a resistance about 1k ohm and its glow nice but the voltage at under the typical voltage of the led 
So i lower the resistance and its glow more and the voltage go more BUT! The heat is going up in the resistor . finally i get 10 ohm resistance and the voltage on the led read 1.5 maybe or 1.6 but the 10ohm resistance is too hot and its becoming hot very fast.. any way 
I link the led directly to the battery to figure out what the problem and yeah the led is dead and  after its dead its now reading the voltage of the battery its self wich is 3.99 (with very very very very ultra low glowing) 
I dont understand even with low resistance the voltage of the led that its taken from the battery is not able to go upper than 1.6 or 1.5 (i need it 1.7 - or 1. 8 - 1.9) 
Why? 

And i have second question wich is the company of the led how can they use 700ma with 1.7v?  Im talking about the ampere because every time i measure it its read under 100ma so how? 

And also i have third quastion wich is linked to the second one 
Does the ampere of the battery that the battery provide it is changeable proportional to the load?


  [1]: https://i.sstatic.net/Khogm.jpg