Now I need to buy a flashlight for my farm works.Do you have some excellent flashlights to recommend to me?Very appreciated if you could help because I am not so professional in the flashlight.Thank you in advance!
Agustin
Welcome to BLF!
Do you have experience with Li Ion?
Check out the topic about Li Ion Safety 101, a link is in my sig!
HELLO!! Welcome to the community! And yes, if you are unfamiliar with Li-Ion batts, follow what TheMiller told you 
Now to advise you, we need to know your use, farm size and duration needed to run the light….
Do you have a budget in mind?
Then the things to consider are:
-how big or small do you want it to be?
i.e. There are loads of great lights these days that will fit in your pocket. That means you can carry it with you always, and have it when you need it.
Big lights don’t fit in your pocket, so you need to keep them somewhere and even to carry around require you to use one hand to hold them.
-What sort of runtimes will you need? And how frequently will you want to charge it/swap the batteries?
i.e. battery tech has moved on miles, so many small torches will have great runtimes. But there is no denying most large torches will run for longer on a single set of batteries.
-What sort of use will you use the flashlight for?
i.e. different flashlights will produce different kinds of beams. If you are wanting something to scan the fields with and light stuff up at distance, then you’ll probably need a larger light, because as a rule larger reflectors throw the beam further. But up close you may find such a torch isn’t very helpful as you’ll get a blinding bright hot spot and it’ll only light up a small area.
A floody light will be ideal for close up use or shorter distances, but will be less good across the fields.
My first question is always, “Whaddya gonna do with it?”.
Close-in viewing where you want a nice even floody beam?
Long-distance spotting of owls in trees (or coyotes, maybe also in trees)?
Need high brightness, or long runtime?
Disposable cells okay, or prefer rechargeables?
Daily heavy-use, or occasional use?
Etc., etc., etc.