CoolFire - UV Free Solar Watch Fast Charger for All Eco Solar Watches for Men, Reloj Hombre Portable Battery Charger, for All Kinds of Sophisticated Eco Solar Watches (Black)

I received my Amazon order for two of these chargers and I immediately tried them out. Each one can be powered in three ways: 1. Mini USB cable. 2. 4.5 V DC power supply. 3. 2 AAA batteries. When you use the AAA batteries, only four of the LEDs will light up. I don't know how well the four LEDs charge a solar watch because I only tested my chargers with the batteries to make sure that the battery terminals were making good contact. I never ran them for any length of time with the AAA batteries. For the long term test, I powered my two chargers with one of these Vivitar USB chargers that has two 2 A USB outputs: https://www.amazon.com/dp/B005GCMYAG/ref=cm_cd_asin_lnk Note that if you plan on getting a dual USB output charger similar to what I bought, look carefully at the current output through the two USB ports. I found that most of the units do not have a full 2 A output from both USB ports. Most of them have 2 A from one and 1 A from the second one. Ideally, you want as much current as possible (2 A) from both USB ports. The Vivitar one that I mentioned above was one of the few with that option. Despite what the Amazon reviewers said, I have had absolutely no problems with the one that I bought. The solar watch LED chargers are made from very thin black plastic and they are very light weight. I would not even think about taking them on vacation with me because I don't think that they'd survive bouncing around in a suitcase. They are plenty durable enough for what I intend to do with them though - sit on my dresser and charge up my Casio, Seiko, and Citizen solar watches once a month. I put two of my most favorite Citizen Eco Drive dive watches on the new chargers: my Eco Zilla and my Promaster Aqualand Depth Meter diver. Both watches rested on top of the chargers' rubber bezels without extending beyond the bezels' outer edges. The chargers' rubber bezels are great because they did not scratch my watch bezels. The LED chargers worked great! I have never run my solar watch batteries down very far (that will shorten the life of them) but my depth meter dive watch has a power reserve meter on it and it was down to about 75% charge before I started my test. After about three hours on the LED charger, the meter was up to a full 100%. Even though my two watches were fully charged up, I decided to leave them on the LED chargers for a full 24 hours. After sitting on the chargers for the full 24 hours, my watches were only a little bit warm and not dangerously so. This is a major benefit to using these LED chargers versus leaving solar watches on a windowsill where they can really cook. Also, unlike sunlight, LEDs do not give out UV light so they will not fade watch dials and hands. Fading hands is a big problem with some Citizen Eco Drive dive watches with bright orange minute hands if they are left on a windowsill repeatedly for recharging. The chargers come with two different sized rubber bezels. Supposedly one is for woman's watches and one is for men's watches. I only used the larger one for men's watches and it worked just fine. It was able to accommodate both my largest watch (the 50 mm Aqualand Depth Meter BN2021-03E diver that I ran my first test on) and my smallest watch (a 40 mm Citizen BN0000-04H diver.) Both fit just fine though the larger watch rested on the highest top surface of the rubber bezel, while the smaller one fit down low inside the bezel on its sloped/inclined surface. All of my other solar powered watches in between those sizes fit just fine on the chargers. When resting my large Aqualand Depth Meter and Eco Zilla watches on the chargers, the bumps on the surfaces of the bezels caused the bezels to not sit 100% flush against the chargers' rubber bezels all the way around. Those gaps between the watch bezels and charger bezels let some of the light from the LEDs shine out and into my bedroom. My wife complained about the light on the ceiling last night when she was first went to bed but after she shut her eyes, she fell asleep in a few minutes. She slept just fine throughout the night so the light spilling out from the chargers may seem like a lot at first, but once you close your eyes you won't notice it. My smaller watches like the 40 mm Citizen diver I mentioned before that fit within the bezel did not have nearly as much light spill out. Also, in theory, a watch bezel that is perfectly smooth will rest completely flush against the charger bezel and prevent any light from shining out and into the room. None of my solar watches have smooth bezels so I did not get the chance to test out that theory. So I give these little solar watch chargers two thumbs up. For what they are, they're not the cheapest things out there, but if they keep my solar watch batteries from going dead and keep my watch hands and dials from fading, they're a great buy. Some of the negative comments/reviews for these solar chargers say to just leave solar watches on a window sill to recharge them. Here is my reply to that idea: Putting a solar watch on a window sill exposes it to lots of UV light. That harsh UV light can fade the dial and hands if they are brightly colored, as are the minute hands on several of my solar diving watches. There are pictures on the internet of badly faded dive watch dials and hands from people that made the mistake of using a window sill to recharge their watches. Unlike sunlight, LEDs like what are used in this charger do not give out a lot of UV light (some sources say that LEDs do not put out any UV light) and thus they will not fade anything that they illuminate. Also, if you have a Citizen Eco Drive watch, the instructions clearly state to avoid charging the watch in an area that becomes hot like a car dashboard. A window sill in direct sunlight can easily become just as hot as a dashboard. Too much heat is not good for the movement in solar watches. Of course, you can just wear a solar watch to recharge it (unless you're nocturnal) but when you're a watch collector, usually you have too many watches in your collection and your solar ones only come up in the rotation every few months at most. As a result they don't get the necessary wrist time to sufficiently keep their batteries fully charged between the times that they are worn. Letting solar watch batteries die repeatedly will drastically shorten their life. As others have found out the hard way, these chargers will not fix a completely dead rechargeable battery in a solar watch.

I saw this little charger after buying my first solar watch -- a Citizen PCAT Eco-drive. Decided to buy this for supplemental charging despite the many reviews critical of the low-quality construction, and I'm glad I did! Sure, the quality of manufacturing is exactly what we've all come to expect from Chinese products, meaning it's cheap. But it also does exactly what it promises to do, i.e. it charges your solar watch very quickly. It includes two rubber rings of different sizes which surround the LED lens bezel; you then set the watch on this rubber ring with the watch crystal facing down. This ensures that all of the light emitted by the LED's is contained and directed into the watch. My new watch had a very low charge when I received it, but after 3.5 hours on this charger it was juiced up and ready to rock for six months or so. A few folks have expressed concerns about the heat produced by the charger. After removing the watch from the charger, the crystal was slightly warm to the touch, but no more. I found the heat produced by the charger to be far less than what the watch would be subjected to by leaving it in direct sunlight for 6 hours or so, so in my opinion this is a non-issue. All in all, I find this charger to be well worth its purchase price for what it accomplishes, if not for its quality construction, so I definitely recommend it.

The CoolFire Solar Watch Charger is made of lightweight plastic material with two sizes of rubber rings to cushion small or large watches as they charge. It also comes with a USB cable but not a plug or phone charger. I tried two different phone chargers. Both the 1.0A and 2.0A phone chargers work with the CoolFire Solar Watch Charger so I mostly used the smaller 1.0A. It can also be used with AAA batteries but I didn't try that. I'm not going to buy batteries to charge my watch. One of my Eco-Drive watches requires 30-40 hours of sunlight to charge from completely stopped up to a maximum charge. It's hard to get that much sunlight here in the winter. When my watch arrived it had a very low charge. Even after a couple of hours of exposure to bright light the watch would dip below the full charge mark almost everytime I set the time or used any of the functions. That's when I started using the CoolFire Solar Watch Charger. After about five hours on the charger the watch has never dipped below a full charge. I continued to charge it and now have over thirty hours on the charger. I haven't had any problems with the watch or the charger. This charger will be handy in the winter because this watch is a power hog. The manual suggests five hours of sunlight per month in addition to normal exposure to light. I was initially worried about this solar watch charger getting hot and damaging the watch. This never happened. The watch did warm up a small amount but it was no warmer than if I wore the watch under a blanket for a while. It was nowhere nearly warm enough to worry about damaging the watch. That said, I never leave the watch unattended while charging it. I have three solar powered watches so my CoolFire Solar Watch Charger will get sporadic use during the winter. I've never had an issue with my other two watches getting low on power. I just put them on the window sill in the sun if I haven't worn them in a while. My newest watch is the one that will need the most light to stay charged. 5 year update. I use this solar watch charger for about 1 week each winter, 5-8 hours a day. It tops up the charge on several solar watches to help get them through the winter. One year I ran it about 40 hours to charge up another new watch as well as charging the other watches. This solar watch charger works well but a few of the LEDs have failed. The old model I have uses the very old mini usb cable. The newest model charger uses a usb C cable. I'm ready to purchase a second charger to have ready if my old one fails or more LEDs fail. Availability of this product has been sporadic so I will buy it while it's available. Despite it's lower quality this charger works well and is the best option I've found for charging solar watches each winter. Still five stars. I didn't expect it to last forever.

I'll start by saying I like the product but with the caveat I've only used it a few hours. It may have started life as a head lamp rather than a watch charger. I don't mind that. It does charge the watch. My Casio GShock was at a medium charge level. The watch only shows low, medium, high so it could have been at the high end of medium. It moved to high within less than an hour. It could have been at the low end of high, but it was changing. It might take much longer to fully charge the watch. I'm leaving the watch on for several hours to hopefully charge all the way up. So, at first glance the unit seems to be working OK. Some reviews mention overheating. My charger and watch get warm. Nothing more. One review mentioned the charger damaging a watch. Thus far, I haven't had a problem with that. I have not tried the unit in the battery switch position, only the USB switch position. It works fine with a USB battery bank. I docked one star off my rating because of errors in the ad and documentation. Light output: Lumens is a light measurement many people know. It refers to total light output. A 100 W equivalent LED light bulb (about 16 actual watts) puts out a total of about 1600 lumens. 1 Lux is 1 Lumen per square meter. So, it accounts for area of the beam. I looked at several videos about the difference between lumens and lux and my eyes started to cross. Don't get hung up on the numbers. Problem 1: Ad says 30,000 Lux. Manual says 40,000 Lux. They should at least be the same. As a consumer familiar with light bulbs, which are usually rated in lumens, and not beam lights, I cannot say if this number is accurate. I will note though that this unit only has to produce very bright light over about 1 square inch, and it does do this. Do NOT look directly into it. The info says it replaces the sun. A bit of googling says the sun puts out about 100,000 lux, so I find this claim dubious. As an example, the sun has trillions of total lumens, but only 100,000 reach the Earth in our particular direction. Problem 2: The info says the USB input is a MINI plug. It's actually MICRO, which is more common. That's fine with me, but I ended up buying a cable I didn't need because of that. Problem 3: The ad mentions a 4.5 V AC input, but the label on the device says 4.5V DC. I assume DC is correct. The barrel plug connector seems a bit redundant when you can just run this off of micro USB. So, bottom line, I like the device from first impression. It seems to do what it claims. The ad and docs have errors in them. Hope this helps.

Works great!

As the title says. This will work with any solar/Eco-Drive/Garmin wrist or smart solar device. Powerful 40,000 Lumen output charges my Citizen fully in just 10 hours. (high setting powered via USB) In the box you get a booklet of instructions, 2 silicone rings to gap the watch face just far enough away to prevent substantial heat buildup. And one USB A to Mini USB cord for power supply. It has an internal AA battery compartment for low power charging on the go. The mode selector switch only work on "High" with USB cable connected to a power source. It will NOT run low power charging unless there is a set of AA's in the compartment - and honestly, it's output is weak. Much weaker. By the time you run down the AA's, you *might* have half charged an Eco-Drive. In a travel, or weather emergency, I guess it is better than nothing at all. The two different silicone rings mate to the faces of various sized watches, so try them to get the best light leak free interface. It does not come with a square "Casio" Tough Solar specific ring, but you can still balance one on top with the round rings just fine. Note: The charger ships with a scratch resistant film applied to the face of the lens. Remove it to gain full, unobstructed light and overall performance. I only used it with USB power, and the "High" output setting. It works very well for my purposes. To revive "dead", inoperable devices, follow instructions from device manufacturer to stop your movement or "shut down" your smart watch and then leave it up on this charger for at least 2, maybe 3 days. It can pull them back from the dead, provided that your solar cell is in good condition. No amount of charging on this device or days left in direct sunlight could pull a completely failed device back to life. I have unscientifically measured the light output on the high setting using an Android phone with a light sensor app that used the proximity sensor on the phone. Point blank, resting on the rubber ring I measured (A slightly jumpy) 39,500 ~ 42,000 lumens. The lightweight and small construction makes packing it simple. Use is as simple as finding a ring that fits. Prop the watch up on it and turning it on. I find an overnight run while I sleep to more than adequately keep my solar watches running at their best. No fear of overcharging or overheating my watches - the puck runs cool. My watches have built in overcharge protection. You just have to be patient depending how discharged or dead your watch is. Charging on high is roughly equivalent of 40% of full sunlight in high noon, so calculate roughly how long you need to set your device on it. It was a no-brainer purchase as I am a night owl. I rarely see full, or daily sunlight, nor have enough ambient light to at least maintain the hybrid battery charge in the long term. This simple to use gizmo takes care of all that and any charge anxieties you may heave.

This thing charges my watch like I left it on the surface of the sun. It's great. Small footprint. Just plug in the USB.

Works great for my citizen eco drive.