Best Electric String Trimmers and Lawn Edgers: Review

Best Electric String Trimmers and Lawn Edgers Review Part 1: What you need to know

What is the best electric weed whacker, weed eater, lawn trimmer, string trimmer, lawn edger? These are all the names for a light, powered, hand-held lawn edging tool, which is the second most important lawn tool after the all powerful lawn mower.  What should we pick when we are looking to edge lawn or beds as painlessly as possible?

In this review we will discuss what you need to know about edgers and trimmers, and what makes for the best products. We will  compare when it is best to pick gas, corded, or cordless models, and edgers vs. trimmers. Then we will compare and rank electric string trimmers and lawn edgers.


What you need to know about string trimmers and lawn edgers

Edgers and trimmers. Edgers are what you use when you need to cut a vertical edge, such as right alongside a concrete sidewalk, while trimmers are what you use when you want to cut mostly horizontally, such as taller grasses, or weeds. An edger typically has several wheels. A trimmer does not touch the ground. A trimmer edger typically has no contact with the ground, but the cutting head can be rotated horizontally or vertically. Trimmer/edgers are a variety of trimmers where the cutting head can be rotated 180 degrees, giving them more flexibility, but not making them the equals of true edgers.

Gas vs. Electric. Traditional edgers and trimmers have been, in the past, gas powered, although this is quickly changing. Gas powered trimmers and edgers use 2-stroke engines, where the user needs to mix oil with fuel, and 4-stroke engines, where there are typically separate oil and fuel tanks. Everything being equal, 4-stroke engines are better, but are typically heavier than 2-stroke engines.

Corded vs Cordless. Corded trimmers are connected to an electric outlet with an outdoor power cord. As a result, they are constantly tethered and limited in reach by their cord, but they also do not need to carry the weight of batteries (or of a gas engine and tank) and can be built much lighter. In fact, some corded trimmers can be as light as 3 lbs. Cordless trimmers are not limited by their cord, but by the autonomy of their battery, which is rarely more than 30 minutes, and more often 15 minutes. Some cordless models come with two batteries, so that you can swap to the second battery if you run out of power.

Corded: heavy duty extension cords. Electric corded trimmers do not come with a power cord, and it is necessary to purchase an extension cord to use them.  You must be aware that the thickness of conductors in your extension cord may make a big difference to the performance of your trimmer. They higher the power of the trimmer, and the the longer the extension cord, the thicker the conductors should be. The thickness of the conductors is measured in gauge, typically varying between 16 gauge, 14, 12, and 10 gauge. In general, unless you use very light duty edgers, we advise that you use no less than 14 gauge for a 50 ft extension, and 12 gauge for a 100 ft extension (a smaller gauge number indicates a thicker conductor). As good quality extension cords are heavy and thick, we advise you use a extension cord roller for cord storage. We do not advise the purchase of 10 gauge extension cords, as they are extremely stiff and difficult to use - they are better reserved for winter use of equipment such as heavy snow blowers.

Cordless: Lithium Ion (Li-Ion) vs. Nickel Cadmium (NiCad) vs. Nickel Metal Hydride (NiMH). NiCad batteries are the older technology, followed by NiMH, then by Li-Ion. NiCad batteries are long lasting, with a good number of recharge cycles, but heavy. They might have cycle memory problems, meaning that if they are partially charged then discharged, they may top off at the partial charge level from there on. NiMH batteries are lighter and can carry more energy per lb than NiCad batteries, but have less recharge lifetime cycles, self-discharge faster, and drop voltage before being totally depleted. Li-ion are the lightest batteries, have the longest lifetime (in number of recharge cycles), work better in cold weather, have lower self discharge, and charge faster, but may be damaged when stored at very low charge. Overall, Li-Ion is the best technology and should be preferred. Most manufacturers are in the process of switching to Li-ion technology.

Lawn string vs blade trimmers.  Traditional lawn trimmers come with a spool and a string. The string is what is rotated at high speed (around 7,000 rpm) by the trimmer to cut grass, weeds and bushes. Every few minutes the string gets damaged and cut, and more needs to be pulled out, often by bumping the bottom of the spool on the ground. Some models allow you to swap the spool with a blade, or only come with a blade. A blade works much longer, but may fail catastrophically, leaving you with an unusable trimmer until you have purchased a new blade, or, worse, possibly injuring the user or a bystander.

Trimmer Strings. Strings typically come in two sizes, 0.065" and 0.080" diameters, depending upon the trimmer model. In general, larger diameters are more suited to heavier work. It is normally possible to use only one size string in a given trimmer. Most trimmers cut with only one string coming out of the spool, although few models will have two strings cutting simultaneously. It is in general possible to buy replacement spools already wound (typically more reliable), although many manufacturers will also let you purchase large quantities of string that you may wound yourself on the spool (less reliable but more economical).

The Hateful Auto Feed Spool. In the past few years, many new models have featured what they called "auto feed," meaning that these new feed spool systems dispense more line automatically, regardless of the actual need of the user, for instance every time you release the trimmer grip. These auto feed features have been a tremendous source of frustration to consumers, radically lowering the approval ratings of new trimmer models, They also result in radically higher consumption of feed line and high ongoing costs. Worse, some manufacturers appear to be making new spool models much harder to wind, and seem to be trying to compel average users to buy much more expensive pre-wound spools. String trimmers seem to be evolving towards a printer model, where the trimmer is practically given away and becomes a low quality consumable, while the profit margin is int he spool recharges.

Cut Path. The width of the path which is cut by the trimmer is called the cut path, and varies, depending upon the model typically between 9" and 15". Larger cut paths allow you to work faster, but often with less precision. Trimmers with larger cut paths are also typically heavier.

Eye and Foot Protection. Edgers and trimmers, while being operated, violently throw bits and pieces up in the air, and can be a significant danger to yourself and to onlookers. It is necessary to wear eye protection (safety goggles or glasses) and shoes when you operate one, or when you are in the vicinity of one.

Next we discuss what makes good string trimmers and lawn edgers... so come back soon!