Amazon calculates a product’s star ratings based on a machine learned model instead of a raw data average. The model takes into account factors including the age of a rating, whether the ratings are from verified purchasers, and factors that establish reviewer trustworthiness.
I have not fully pushed this past 250w so far but it works beautifully. Even though the fan runs its silent, and even when it speeds up, it’s virtually nonexistent. This is what I cared about the most after clean power. (Which it does.)
I attempted to use the 300W with my notebook despite the rating on the Apple P/S of 92 watt, which of course, failed. I passed the 300W along to a Mac Air Notebook user. The 500W is quiet, & charges my notebook without issue. My only suggestion would be to provide a cross reference of acceptable units vs inverter models for the various notebook community.
Living in Florida, I am always looking for back up energy sources to stock up on, before hurricane season! This fits the bill! I will give it to my son to keep in his car for any emergency. It's very simple to use and have had no issues with the unit keeping a long charge!
Nice Product for the price...It is Modified Sine wave. Some items will buzz, ie. fan motors and UPS battery back up will not run on Modified Wave. All other items seem to run fine. Fan only comes on when needed, so unit is nice and quiet unless you are drawing near to max power.
This product works really well. Quite, and light, and it has a good surge current. I'm running with it a mini refrigerator, and it sustains the compressor's start surge current. It's a good product, at a very affordable price.
So far about a half hour test this morning. Connected to a scanner for the test. Clean signal with clear sound. So far very happy with the workmanship and product. I like that I can use the accessory plug or direct clamp to the Battery. I haven't tried the USB plugs yet but what a bonus. Small, light weight and so far, very light load, the fan has not turned on. Updated 5-23-19 I tried this out on a extra stereo receiver I have the other day, no outside noise was detected and worked great. I then connected a halogen light, 4 ft, and ran it for about 45 minutes at the same time as the stereo and it worked great. I am very happy with this purchase and now have bought a 1000 w, can’t wait to step my small solar setup further