It's the best 15A output controller on the market. If When combined with the Morningstar SureSine 300W inverter (also a category killer in fanless sinewave inverters) and appropriate battery capacity/panel output, a user has the ability to run DC appliances and small AC appliances with the remote panel or a (antique-no-cost) PC to monitor system performance. There are so many options and variables that a user will need to spend a few hours understanding the manual, so it's not "Plug n Play". The pay off of a good install is long service life in that the electronic modules are sturdy and designed for dirt-floor-hut type "no-maintenance", meaning that they should be provided with air circulation and protection from bumping in a place that absolutely-positively will never have weather exposure or dripping water, but don't have fans or filters to change & fail. Since these are only able to put out 15A, they can be paralleled without confusing each other. They have a max input voltage of 75v, and can be killed by exceeding that input even briefly (new panels can put out more than rated power for the first 6 months, and cold bright weather with clouds and focus light with clouds to make more than standard illumination, so give yourself some margin!). Your batteries will not charge if you use a 18v panel with a 24v battery system. MPPT will adjust voltage down but not up.This Morningstar MPPT 15L solar charger is an amazing product, the settings are factory set to actually charge a battery, unlike so many others.The charger is well built, and well designed. Wiring connections are secure.If you get the computer connection module that goes with this, you can change all the charge settings, and the free software from Morningstar gives great graphing and control. One note, if you do change the charger settings, you must power cycle the charger locally for the new settings to take effect. I have had quite a few solar chargers over the years, that would simply pull back too soon to get the battery charged, this one is just amazing. I use this charger with a 250w 40 volt panel, and it all works great. Some other features are a low voltage disconnect if the battery gets so low it is might be damaged, and a lighting control of the load terminals if all you are going to do it night lights. Take a look at the Morningstar products, you will not be wasting your time. If you do get the computer interface, the metered parameters are amazing, way more then I will ever need for sure.Absolutely the best small charge controller ever, pricey but worth every penny.Programming is not straightforward, but if you are using AGM, Gel, lead,.. you don't need to do anything other that set toggles.I will never understand how the cheap ones will last long. This is a high quality controller.Running dual 300W 36V 9A (in parallel) to 24V Li-Ion pack, no BMS, early morning bulk is important for me, so i dont care about waste during day..It works great but for those that may have equipment sensitive to RFI such as Amateur Radio receivers, The RFI is a very high on certain frequencies.Otherwise it responds very quickly to power demands.I run two one hundred watts panel in series for twenty four volts to get the most out of my MPPT controller. Do your research as to what your power demand is and how much it will cost.A MPPT controller on a single one hundered watt panel does not provide any real gain.Again do you own research for the type of panels and controller for your own system.This company has been around nearly 3 decades, and it shows. Simple, easy to use, sturdy products. Worked perfectly upon install. What's more, with a few flips of the 4 dip switches, it can charger lead acid, gel, AGM, and Lithium Ion too. The network cable provides connection to your laptop (which I am looking forward to purchasing soon). I was able to mount this on the inside of my 2000 Subaru Forester, inside one of the rear, side pockets, above an AGM motorcycle battery. In conjunction with a Renogy 100W panel, and MorningStar inverter, I now have a totally self-contained electrical system for running my laptop, charging cameras, on the go.This is a great, reliable MPPT charger. However its expensive and doesn't detect end of charge. Charge termination is purely timer based which means that your batteries may not ever be fully charged or they may get over charged.There are other feature rich and better priced MPPT chargers on the market from reputable manufacturers. Do your research before buying.I run two solar panels in parallel and my three year old Xantrex controller gave up the ghost while on a two month cruise. A good local supplier firmly recommended this Controller as a 30% more efficent ( better electronics/ alogarithm) controller. I cant measure or comment on the efficiency part but it is much more compact, easy to mount and install and works will. I like the fact that it gives me a visual idea of the state of charge of my batteries with three LEDS .My Prime membership gave me free delivery in less than 48 hours from South Dakota to the Florida Keys - that was impressive- and I was repaired and on my way !!Am using it for my Solar system for Ham Radio. Has significant radio hash. Would have had a different brand but the other folks stop making them. Works as advertised and does a fine job regulating 24V 100amp solar panels into a 100 A/H AGM battery. Yes, kind of spendy but does the job. Hope it lasts longer than 5 years.Easy to install. . Used to control battery charging via a 200 watt solar panel