O2COOL Treva Fan 10 inch Battery or Electric Operated Indoor/Outdoor Portable Fan with ac adapter, Tilts 90 Degrees

I needed a fan that would run from 12VDC to use in my boat. We have a Church service at the lake during the summer that I enjoy attending, but it can get really hot sitting in the boat tied to the dock for an hour!! I picked this unit especially because it is designed for 8 D cell batteries (12VDC) and not 6 (9VDC). It does not come with a cable for a cigarette lighter, but they are easy to find. Very happy with the amount of air it moves and that it is quiet enough not to be noticed by others. I have also installed the 8 D cell batteries now and useded it for the last two Sundays with only the internal batteries. Don’t know how long they will last but after approx 1 hour each Sunday and being stored in a boat locker (temps in upper 90 degree range) it is still running like new! I am very happy with this purchase and wouldn’t hesitate to buy another. Just make sure it uses 8 and not 6 batteries if you want to plug directly into a car or boat. ;-)Update: Our summer is over and we are back home, but this fan performed flawlessly and was a real life saver during Church at the river! Worked great with a cigarette lighter cable I already had with or without internal batteries, but it definitely stands up better with the weight of the installed batteries ;-). Definitely recommend these O2Cool fans!!!

Love that you can have the fan tilt. Air flow is great

This review is for O2COOL Fan 10 inch Battery or Electric Operated Indoor/Outdoor Portable Fan with ac adapter, Tilts 90 Degrees.The item arrives in a retail box and is as pictured. It is 13-1/2” high, 11” wide, and 4” deep.The fan head swivels up and down as shown in the item picture but can not be fully spun around. The pics I posted show the most down and up the head can be adjusted.This fan can be run on 8 D batteries or plugged into the wall with the included AC adapter. The adapter output is 12v DC @ .5A. The adapter input is 100v – 240v AC @ .2A. The cord is 5 feet long and the supply is UL rated. The power brick only need two blade outlet (no ground pin is required).According to the manufacturer FAQ page it is safe to leave the batteries in while running the fan from the AC adapter. “The fan will bypass the batteries and only use the adapter.” I tested this feature and it works fine.I have read a few complaints about other models of O2Cool fans, that the battery doors fall off easily, so this was the first thing I looked at when it arrived. The door does come of very easily but they provide two small screws to secure it so the door falling off this fan simply wont be an issue. On the downside if you plan to take this camping you'll need a small Phillips head screw driver on hand to change the batteries.The fan moves a good amount of air given it's small size. It definitely pushes a little more air when powered by the AC adapter then when powered by batteries.I bought this to use when the utility power goes out so battery performance means everything for my application. I tested my fan on high because I intend to sleep with in on as background noise. On this point, it makes a pleasant noise, but is a bit higher pitched then a normal box fan.The manufacturer claims on one set of batteries this fan can run up to 25 hours on high speed or up to 40 hours on low speed.For reference D batteries are spec'd at 1.5v but usually start a little above, in my case the Rayovac UltraPro Alkaline D batteries (ASIN: B000A6V8FU) started at 1.6v.There is no firm answer for when a battery is actually dead. But a rule of thumb for regular Alkaline batteries is when it reaches %70 of it's rated voltage it should be changed to prevent leaking issues. So our 1.5v D battery will be at the end of it's useful life at about 1.05v.After 25 hours of continuous use on high speed the batteries measured 1.15v. (0.95v when loaded by the fan on high speed.) So the batteries actually lasted the 25 full hours on high but are more or less fully discharged. It should be noted that the fan still ran but pushed much less air then when the batteries were new. High with dead batteries was more like low was with fresh ones. The batteries could probably be used for a bit longer but if pushed too far they may leak and destroy the battery contacts.It should be noted that rechargeable batteries typically have 1.2v instead of the 1.5v of a standard Alkaline. Since this uses 8 batteries the difference really adds up: 1.5v - 1.2v = .3v lower per cell, .3v X 8 cells = 2.4v total, 12v - 2.4 = 9.6v total. So when fully charged rechargeable batteries are used they will push less air then standard Alkaline counterparts because they have less voltage. Also, most rechargeable hold less energy than standard batteries so they run down quicker.I called O2 cool no less then five times during business hours to get more details about battery use. Four times I went straight to voice mail. The fifth time the operator picked up and transferred me to a voice mail box. So I gave up.So why four stars?Overall the build quality just feels cheap.The tilt-able head has a noticeable shake when it runs, not enough to make it rattle or walk away, but more then a well balanced fan should have.The AC adapter plug in the back doesn't always make good contact the first time you push the cord in, it usually takes two or three tries to make the fan run.I would have preferred some sort of plastic slide lock on the battery cover (rather then screws) so it doesn't require any tools to change the batteries.The instructions are easy to miss as they are printed on one of the inside box flap. And they don't really tell you much, if you have a question go to O2Cool's website FAQs as they are much more in depth.And bad service … answer your phone during business hours.All this said, I would buy the fan again, not because I really like it, but because there aren't that many alternatives to O2Cool when it comes to battery powered fans. While not perfect, it does work, and if I find a better battery powered fan in the future I will update this review and list it here.

Works perfectly. We keep it plugged it, but full of battery so we prepared for surprise power outage in this heat. Luv It. Bought my daughter one for her home.

O2COOL Fan 10 inch Battery or Electric Operated Indoor/Outdoor Portable Fan with ac adapter, Tilts 90 Degrees. This portable electric fan works on dual power sources: AC Adapter (included) or 8-D batteries (not included). It has a powerful 2-speed 10-inch blade fan that offers quiet cooling; its grille pivots for directional air flow. And its compact folding design makes it great for travel, easy to carry and store and perfect for indoor or outdoor use.Well, of course, it’s small size means it’s only good as a personal fan. But where I live, in Wilmington North Carolina, has long been known as a hurricane alley. 2018’s Florence was particularly devastating. I was powerless for 10 days, in 90 degree heat. And believe you me, this fan was a lifesaver.

Nice size fan with the option of running on batteries! I ordered in case there is a power outage.

It's a great little fan...if it works. My daughter and I were going camping so I bought two. (I'm not a fan of tent camping, less so of sweating through the night). When we got them, we put in new batteries that I also ordered on Amazon. (Enough in case the Eclipse turned into the apocalypse) It gave out good power when we tried it at home. We carefully packed them back in their boxes and treated them like eggs. I did NOT want anything to happen to them! The first night my daughter's started losing power. We changed out the new batteries for another set of new batteries. The second night it smelled of burning plastic and died completely. Last night mine began losing power. The fear is real......Well.. the other fan stopped working as well. I even took the batteries out (because by now I'd retreated to a hotel) and tried the plug. It worked for about 60 seconds and then just stopped. It had such good reviews! I would have thought we had one dud, but BOTH quit working. I don't understand. We were very careful with them. So my advice is if you get one, run it for a few days to be sure it works.

A very nice fan. Bit noisy but I wanted it bc it can be used with batteries when hydro goes out!

Used on our boat