Nowadays ,we have develop DC24V Constant current LED Strip , Which voltage drop is very very small , and in fact it is Constant Voltage led strip , so you need to use DC power supply to Power them , so why call then Constant current , it is because we use the Constant Current IC to make sure the Current is same as the first led . 

          For this led strip , we use 15mm Width PCB ,4ounce Copper ,60 PCS 2835 SMD LED chip , 2835 White LED is more brighter than 5050 White . 

2835 SMD LED Lumen is 22-24lumen Per chip , then 60SMD 2835 LED Strip per meter is about 1300-1400lumen those led strip ,if you power one side ,it can reach 25meter with very small voltage drop , then if you power them Both size ,it can reach 50meter without voltage drop .and Each 6 LES can be cut .

        The Item of this Product is on the following 

http://www.szledcolor.com/product/view/id/525