Hi I am wanting to build a flood light for a rural hospital in Zimbabwe it is a project I have been working on for years in a maternity hospital after seeing a 6 hour baby with 60% of its body covered with third degree burns. I have attached a datasheet of some LED's that I have. Firstly the 3 Watt LED's I would like to put 4 into a housing to provide light for stitching patients. Currently they are using cell phone torches. I don't know anything about LED drivers or why they used. Usually I just use an online LED wizard and connect the LED's with series resistors. The power supply will be 12 Volt as we have a solar system charging batteries at the moment. I need to know a suitable driver for this preferably but not essential THM components. I also really need to understand why we use LED drivers and how to look for suitable drivers. The second LED is for some passage lights I want to use this surface mount LED have a housing already and have been using a series resistor combination. But seeing I am doing things correctly I would like to use a driver. I am not sure how many I can use.