20W 12V Solar Panel Kit Battery Maintainer Trickle Charger Pro + Advanced 10A MPPT Charge Controller + SAE Battery Clip Cable for 12 Volt Boat Car RV Trailer Motorcycle Automotive Home Off Grid System

This is a real 20W charging panel, and these MPPT charge controllers are finally smart and only turn on if polarity correct, how many controller simply release the magic smoke if reversed.The only down side of the panel is it need full sun NO SHADOWS, but if a cloud passes over head yes you will loose power but once the sky is clear the system just reboots and starts charging again.excellent power output, it is producing 3x what my "25" watt harbor freight (THUNDERBOLT) panel does, but again because of the cell type amorphous the harbor works better at non perpendicular angles and diffuse light (aka fog early morning) etc. etc.Simply put if you need 12V 10A battery charger/maintainer and you have clear access to clear sky's and you can install at close to the optimum angle this panel and controller combo are the best.If you only have a partially covered of off angle installation then pick up the controller only and then a CIGS or amorphous type (lower peak but wider range of performance) solar panel.I gave 5 stars for tech support because it simply is not needed. hook up battery or panel first and just keep flipping polarity until you see the battery charging. no more multimeters and risk of magic smoke if not hooked up "correctly" the first time.Yes if you don't have a small collection of SAE Polarity Reverse Adapter then get some it seems SAE 2 pole products don't really have an universal standard and the (SAE Polarity Reverse Adapter Connectors) are well worth having on hand if you want to do any system design or use other panels regulators or clamps. in fact I found I needed to use one reverser to use the included battery clamps (when used directly without the regulator) for why see below. (warning not interesting to most folks)Most folks are concerned with efficiency but understand these self powered regulators consumes power. If you have excess capacity panels, small actual battery requirements or long term unmonitored situations then a regulator is highly recommended. Most folks have often the bare minimum panel aka real generation capacity (which we all know then suffers from environmental factors). As "most" new cars have some parasitic drain each night and as the title states these small panels are really just maintainers. unless you have a small car battery (or a motorcycle) and/or it is brand new then chance of over charging in a single day is minimal. I was doing experiments to see if a small panel 5-10 watt size (.2-.4 Ah) could even hold a 14.4 v charge on a brand new just topped off battery, the answer is no. With this real 20W (.9-1.2 Ah) kit I was able to push the holding voltage up to 14.4 so given enough time it does require a regulatorAs far as charging it seems we need to get in the area of (actual measured) 40W-60W (3-4 Ah actual amps) systems Minimum to actually charge a very very new class 49 truck battery measuring 12.5v in the morning (different from unit from above test) both size 49 to 14.4 by the end of one day. This makes sense when you consider that a class 49 battery has about 100 Amp hours stored when full. From there to find how long it will take to charge it is simple math, take the of number of amp hours needed to charge to full divided by actual amp hours your system produces, this will tell you how long it will take.Remember the sun only shines so long every day and no battery is a perfect storage device so in low power systems a regulator may not even be needed just for maintenance. Also remimber Chinese watts are not real measured watts (except for this one) If your building an off grid power system then you need to plan to "charge" and not just maintain a charged battery.So the rule of thumb holds that true .8 - 1.5 Ah chargers are really maintainers and 4+ Ah chargers can actual make up for some usage and loss.So yes this is a great regulator because of a bunch of failsafe design features that prevent magic smoke from appearing plus when operating it provides current voltage readout plus an amperage rate which most regulators do not.

I had been watching both panels and MPPT regulators on Amz for a while when this one went on sale for less than most panels and/or regulators by themselves so I bought it and I'm glad I did. The panel is as good or better than any of the others I have and the regulator works great.I gave 4 stars on the weather proof as, while I haven't seen any performance issues, moisture has gotten in behind the protective plastic over the LCD which makes me wonder as to whether or not it can withstand direct rain or morning dew for long. But so far no problems as a result.I got it to use to keep the backup power on my RV topped off but have been using it for a little bit of everything when the RV isn't in storage. Great little system!

I wasn't expecting too much from a 20 watt panel but this exceeded my expectations. So simple to use. You don't have to take the battery out of the car or even disconnect the negative cable to charge the battery. It even ajusts automatically to the type of battery your charging. Since it's solar, you can charge your battery in the middle of the desert if you had to. It won't charge a dead battery to full in an hour, but to give an idea how fast it works, it charged my agm battery from a low 11.9 amps to 12.9 amps (12.6 is considered full) in about 8 hours of full direct sunlight. This is nearly as fast as my Schumacher plug in charger. The slightest shade or blocking of the panel will greatly diminish its output so keep that in mind. I've been using this for several years now and highly recommend it. It's still working flawlessly.

The frame of the panel has mounting holes. You may need to buy longer cables depending on your needs.

I just received this day before yesterday, tried it out to make sure it worked yesterday. Worked fine. I used it to top off my mower battery, with the panel sitting in a lawn chair outside the shed, and connected to the battery with the provided battery clamps. Worked well. Very impressed.I wanted to buy this MPPT solar charge controller to replace the less efficient PWM controller that I use with my 100 watt panels (4 x 25 watt panels) to charge my travel trailer battery when without hookups. At the time of this purchase, a few days ago, I could get the 20 watt panel and controller for $20 more than just the controller, so why not. I'm pleased with the limited testing that I did using the included 20 watt panel, as well as one of my 25 watt panels.Due to the MPPT efficiency, I should be able to get more charge per day back into my battery when I need it most.Edit 6/28/22: I've used this several times at home to top off my travel trailer battery. I've been using it in conjunction with 4 25 watt solar panels of a different brand, for a total of 120 watts. I checked the polarity of all panels and the final connection to the controller with a multimeter to be certain the polarity was correct. It's been fine, with the exception that the 100% charge LED has never quit blinking, as though I was never reaching 100% charge. Checking the battery after a state of rest indicates that the battery is 100% charged at 12.6 volts.I recently went on a camping trip with no 120 volt hookups, so I was using this setup to maintain my battery. Once, when I checked the charge controller, part of the display was missing, and I felt like the battery probably wasn't being charged. I completed charging with my old PWM controller without issue. When I returned home a few days later, I contacted Allto support, and included a picture of the controller display. They responded within hours, acknowledging that the controller may be defective. They sent me a replacement, which I received in 3 days. It appears to function fine. I hope that it lasts.Excellent customer support!

The item does not work. Control panel doesnt work. Zero power.

Also it recieved enough sunlight to operate the unit it did not receive any charging voltage if under a carport

Looks good not installed yet

Seems to work well will get more if I have a further need