ECO-WORTHY25 Watts 12V Off Grid Solar Battery Charger Kit: Waterproof Solar Panel + Adjustable Mount Bracket + SAE Connection Cable +10A Charge Controller for Car RV Marine Boat 12V Battery

About the best solar battery charger on Amazon.We are off grid and use the charger on a number of battery powered units. Being able to easily and quickly disconnect the long cables from the Charger Controller simplifies moving it from one unit to another. The short pigtails on the Charge Controller permit quick disconnect and reconnect of the solar panel and charging cable. That makes it easy move the tangle of wires and panel to other units to be charged. It also simplifies using different charge cables when using an Alligator cable on some batteries or Ring cables hard wired on hard to reach batteries.The solar panel mounting bracket is superior with a cross piece to fully stabilize the panel.

Best purchase i made i use this solar panel and battery to operate my chicken door works perfectly good solid mounting brackets 2 thumbs up

The solar panel and the charge controller itself work great. The wires are junk, wasting 10-20% of the total solar power and causing charging issues. The charge controller is not waterproof or even water resistant, and it takes patience to attach wires to the green connector. Otherwise, the charger works well. Rather than return it, I fixed these problems for about 15 dollars.Actual specs:I measured this unit putting 1.4 amps into my low car battery on a sunny day in December in Maine. That's about 18 watts in the middle of winter, pretty good for a 20 watt panel. That was before I fixed the wiring.The label on the back of the solar panel has slightly different specs than the Amazon title. It says 25 watts max power. See attached photo.Charge controller:The included charge controller works well. It's an intelligent 3A PWM charger that automatically switches through 3 charging phases: bulk, absorption, float (trickle). It has an LED to indicate when it has solar power and what charging phase it's in. It will prevent over discharging below 10.8 volts and over charging above 14.4 volts.At one point I thought my charger was broken and started looking for a replacement. A decent PWM charger like this runs 15-20, so it's a decent value. I later discovered the charger was fine, the problem was the cheap included wires (see below).I was a little worried about the charger consuming battery power when there isn't any sun. Cheaper chargers use a little battery power overnight and on very cloudy days while waiting for the sun to come back. I wanted to leave my system unattended for months during our short and cloudy winter days without discharging my battery, so I can't tolerate much current drain when the sun is gone. Amazon didn't list the current drain when I bought it. I measured the charger's current drain with no sun at about 1mA. That seems pretty reasonable compared to 10-50mA with other chargers. The charger ships with a spec sheet, which lists the current drain as 1.5mA (see attached).The spec sheet says the charger is made for Gel batteries. It seems to work fine on my SUV car battery though.Cheap wires:I measured my battery voltage while charging on a sunny day. 13-14 volts is normal, but I was only getting 12.4 volts. I thought the controller had gone bad so I tried another one. Same problem. I tried lots of things, went over all the connections many many times but nothing worked. It definitely had power coming from the solar panel, it just wasn't getting to the battery. Over a few days I did notice the battery charge increasing very slowly, but the charger kept thinking the battery was fully charged too soon and kept turning off (trickle mode) too early. I finally had the idea to check the battery voltage at the other end of the battery wires (where they connect to the charger). The charger was putting out 13.6 volts at about 1.5 amps, but only 12.4 volts was getting to the battery. That's 10% of the solar power being wasted by wire resistance! It was also enough to fool the charger into thinking the battery was charged and switching to a low power mode, which throws away even more of the generated power. It will still charge your battery eventually assuming you aren't using the battery for something else, but it will be slow.I replaced all the wire with normal 16 gauge wire, and it fixed everything. I measured 13.6 volts at the charger and 13.5 volts at the battery while charging at 1.5 amps. It charges much faster now, and I can use the battery to power other things. I attached a picture of the cheap wires they include and some normal 16AWG wires I replaced them with. On the outside it's deceiving because the cheap wires look reasonably thick. But if you cut into it you'll see the cheap wires are almost all rubber insulation and have very little actual metal inside.Replacement wire: https://www.amazon.com/dp/B00NSGCVWI/ref=cm_sw_r_cp_awdb_feSyyb487STEMWaterproofing:The actual solar panel appears waterproof and has white silicone around the edges on the back. However the charger is definitely NOT waterproof. It came with clear silicone applied along the bottom of the green connector, but that's pointless since the top and sides of the connector have bigger openings and were left unsealed. I needed the charger to work outside in the winter in rain, snow, ice, etc., so any water intrusion could easily freeze and damage things. You could always buy silicone and seal all the openings including the holes in the green connector where the wires attach, but then it will be a pain if you ever want to remove and reattach the wires later. I ended up opening the charger box and spraying conformal coat to waterproof all the electronics. Then I drilled a 1/8" hole in the white box to allow any water that gets in to drain back out. Takes about 10 minutes. So far it's holding up well to our Maine winter environment!Conformal coat: https://www.amazon.com/dp/B00BXSMNWG/ref=cm_sw_r_cp_awdb_AbSyybQ2NH5G4I didn't see any of this information posted anywhere else, so hopefully some people will find this info helpful!

Update: I have a number of these. As others mentioned the original charge controller did not function properly. In extended low light weather conditions, they would not disconnect the battery from load. The battery would discharge far below a safe level, potently damaging the cells. Eco-Worthy has taken note and correct the charge controller issue. I have two of the new version controllers and they work 100%. I have tested these new kits with both AGM and Lithium LIFEpo cells and can find no issues in my environment, The newer kits are solid performers and a great value. Grab a kit while they are in stock

I now own two of these and I still can't get the eco-worthy controller to show only LED 1 which indicates a sealed battery. It always shows LED one and two. The directions are confusing or inaccurate. This controller cannot recognize a battery for what it is. Again I have purchased a small MTTP controller that has no trouble whatsoever identifying what my battery is.___________________I gave this a five stars because it seemed unfair to ding my review over the fact that the controller that came with it to proved to be unworkable. After 6:00 or 7 readings of the directions I was unable to make the controller recognize and AGM battery. The AGM would go under sealed battery but it kept staying on two lights which meant that it was either a lithium battery or a gel battery. You can't run an AGM battery on anything other than sealed or AGM. For that reason I had to move to a tiny MTTP controller that worked instantly and made it very easy for me to link the battery with the solar panel.I think that it's a very nice system and I'm using it to trickle charge and AGM battery over winter. My plan is to buy another one of these and set it up in the same way to trickle charge over winter a typical sealed battery.Here is something you'll really love. I set this up approximately 24 hours before hurricane Helene hit the mountains of Western North Carolina. The solar panel was set up on a 4x4 post with a 2x4 support that formed a cross. The cord on the panel is very long and makes connection into a outdoor storage cabinet very easy. I then connected some green covered ground wire to a 4 ft piece of rebar next to the 4x4 post. I then stapled the ground wire such that it was not going to pull on the solar panel. The result was very pleasing. It's survived 40 to 60 mile an hour winds.I do hope to figure out why I was unable to program the control panel that came with it.

Used to charge a dump trailer, works good