This is a great trimmer for home use. It's light, can do both trimming and edging, and has improved significantly over the previous model.

The cordless concept gives you a lot of freedom. I have a corded edger with a blade and it's great for the really challenging parts of the lawn, but nothing beats the convenience of this cordless model.

How well does it trim?
For a home with a front and back yard (probably around 4000 sq ft lawn space) I found the 3Ah battery just enough to cover both yards if using a judicious mix of the two power settings. The low power setting is fine for most of the trimming and even some of the edging, but I use the higher power setting for thicker growth. This is for St. Augustine grass common in the south. If you have hardier substances to cut or if you need to use the higher power setting more than I do you may have to charge in the middle of the job and it does take a while to charge an empty battery. You can also buy additional compatible batteries on the Black and Decker 20v systems on Amazon which I would recommend for those with larger/tougher jobs.

Which one is for you?
The biggest differences with this model series are the batteries they come with and the string feed mechanism. I've included a chart to help understand the differences between the models. Some thoughts:
- The basic 522 and 523 appear to be physically identical trimmers except for the string feed. The 522's is automatic, the 523's is manual. My old 400 had an automatic feed that worked but there were times I would have liked to have been able to feed it when the automatic didn't trigger.
- The 523 appears to be sold in two options (at least it was when I bought mine). One option comes with a 3Ah battery, the other comes with a 1.5Ah battery. The bigger battery is heavier but lasts longer. If you have a smaller lawn, or you want the lightest weight, maybe the smaller battery unit is better for you. Although the unit is not heavy, you may feel it after using it for forty minutes. Again, if battery life is an issue, Amazon sells additional batteries separately, and they're compatible with the whole line of Black and Decker devices including cutters, drills, and more.
- The 525 seems to be identical to the 523 but comes with a choice of either a 3Ah battery or two 1.5Ah batteries.
- The entire 500 series (522, 523, etc) are a big improvement over the 400 series due to modifications to the trimmer/edger conversion mechanism and also the change of the auxiliary handle's friction clamp to instead a fixed pivot point on the handle assembly. This makes the 500 series easier to use and more reliable.

6-Jun-2019 update: Saw a bunch of negative reviews from people that had issues with quality control on their units. I don't doubt them. I had issues with the previous generation of this unit. All I can say is that even with issues, I got four years out of the previous model and this one so far has worked fine. Stories of the awful (and probably outsourced) support from Black and Decker are disappointing, but that's the price of dealing with some corporations.

I ordered this string trimmer after our older gas trimmer bit the dust and I couldn't be happier. This Black and Decker trimmer is battery powered and comes with one battery and line too. The trimmer offers something I have never seen on other trimmers and that is the line advancement button. During the trimmer running you push a button on the top and the head comes to a fast stop, and this action advanced the string line to just about perfect length.
The battery lasts a good long time and I trimmed at the higher speed as I wanted to see how quickly it would run down, I was not disappointed, it ran the job with power to spare. I ordered 2 extra batteries before knowing this, I would pick up only 1 extra battery, do to this information.
This trimmer has so many extra features that I cannot name them all, but trust your own eyes and pickup this trimmer now, out of season, for great deals. The trimmer is a quality product from a great company, Black and Decker.

The item arrive in a few days. Shipping box had minor damage, however the B&D box inside was not. Item is brand new and took about 5 minutes to setup and get ready for use. The single Li-Ion battery is rated at 20V @ 3Ah. Unit comes with proper charger too. I was scepticle of the charger because it's small size and overall feel. I decided to open it up and look inside. It has a small circuit board with a proper integrated circuits and microprocessor. This is VERY important because each cell in the Li-Ion pack MUST be properly charged and monitored. This one has it.

Although the battery is rated for 20V and quite a few other models are rated at higher voltages, it's really the Amp Hour (Ah) capacity of the battery that determines overall run time. That's what I want... long run time. The battery charge time with the included charger was surprisingly long for a Li-Ion battery pack. The instruction booklet states 7 hours to charge, although you can purchase a larger B&D desktop charger that will cut that time down to 1-1/2 hours.

The weed whacker itself comes with a single trimmer line installed and is very easy to change and rewind a new one. The unit also has a line-feed button to extend more trimmer line when needed. Unit does NOT require bumping to extend the line. Device also has a speed selector switch (Hi-Low) that is easy to select while using. We found that the low speed setting was adequate to trim our whole front and rear yard with a single battery charge. Plenty of power. We would prefer if the adjustable / extendable length control would allow the unit to be extended just a few more inches in length, to avoid having to lean over slightly while using. Also, the unit can have the trimming head rotate 180° to allow the device to act as an edger to trim the grass at the sidewalk.

Only complaint is, the adjustable angle grab handle doesn't lock into position very securely and feels a bit flimsy.

Overall we are very satisfied with this device. It cost about $17 less than the sale price at my local Menards store.

So light I almost sent it back, but it works well...takes a couple of times to get used to it...I am amazed how that thin cord edges so well....

I can't believe it took 2+ weeks to ship to me from Amazon warehouse even though I'm a Prime member. 20V MAX trimmer works fine.