Weed eaters also known as weed wackers or string trimmers are one of the must have lawn care tools these days. I can't imagine using a hand trimmer around my yard. They can trim grass and weeds along fences, buildings, stone or rock walls or under bushes and gardens where you can't reach with a lawnmower. A great addition to your lawn maintenance toolkit. They cut grass and weeds by spinning a nylon string or piece of plastic, like a plastic tie, and can be powered either by corded electric, rechargeable battery, gas motor and recently propane power.
Determining which type is the best fit for you depends on how large an area you need to use it on, how long it will take you when you talk about battery powered and how much power you need. They also have different ways to replenish the nylon string or plastic. These systems can be frustrating when they don't work right. Many have a bump feed system where you tap the bottom on the ground and it is supposed to feed more string out. When the string runs out you need to wind some more string onto the spool. Others use a plastic tie the snaps in or runs through a couple of slots.
Electric corded: This type is usually the lowest cost weed wacker, lightweight and easy to handle. The motor is usually 5-7 amps and mounted either near the handle (good) or near the bottom where the cutting string is (not as good). For ease of use it's better if the motor is mounted near the handle. Most do not have the power of a small gas powered trimmer and the major drawback is that they need to be plugged into an outlet. If you have to do both sides of a fence it can be quite a hassle dragging the cord over the fence to get the outside. Most will come with a bump feed for the string which you have to refill by winding a new length of string.
Cordless: These give you the freedom of not having to plug into an outlet. Unfortunately your freedom is short lived as the batteries usually are good for less than 1/2 hour. They also don't have as much power as the corded models, nevermind comparing the power to a gas trimmer. Avg weight is about 8 lbs. Most have a bump style line feeder. The biggest drawback is lack of power.
Gas Powered: With more power you also get more weight and higher cost. They come in 2 stroke (they need oil mixed with the gas) or 4 stroke (quieter and less pollution, but heavier). You can also have more breakdowns because 1. they are usually pull start and 2. they need to be lubricated. 2 stroke models are cheaper and still have more power than their electric counterparts. Read customer reviews for durability.
Propane: Propane powered are fairly new. The advantages are that they have just as much power as some gas powered trimmers, and they are environmental friendly. You don't have the typical motor problems of gas powered but you do need to buy new propane canisters. So availability of the canisters can be a problem.
