Morningstar SunSaver Duo 25A PWM Solar Charge Controller (SSD-25RM) - Solar Panel Regulator for Two 12V Batteries, Adjustable Charge Settings, Includes Remote Meter, 5 Year WTY - Designed in The USA

I needed a controller that would independently manage two batteries and this one seemed to have the right stuff. After reading the detailed online documentation I was quickly convinced that this device was NOT Harbor Freight quality. Another good thing is that it has twice the current-handling capacity that I'll ever need for three 100W solar panels, meaning that it should last for dozens of years because it will never be "driven hard" or "worked at capacity". That, combined with the 5 year warranty made it a no-brainer to take the chance. Before installation in my RV I contemplated the many options for wiring and switching, etc, and then sent a note to their technical department seeking advice. Response was immediate, knowledgeable and thorough, helping me to better-customize my installation design. It's now been up and running for over two weeks and it does everything they said it would. Solar is the best thing that ever happened to an RV camper, and anyone who has ever depended on RV batteries knows how much work it takes and the cash it costs if you don't have well-managed battery maintenance. Batteries are a "living thing", and without careful care and feeding they won't be there when you need them. This little gem takes care of them FOR you, while you do other FUN stuff. And with my 300W of Solar potential, I'll not have any problem topping them off while living off the grid each day. One more footnote: As much as I've been in the electrical/electronics field for my entire life, I am more prone to do stupid things like mess with wiring while the circuit is hot even though I know I should NOT. Well, I did it here too, and I was in a hurry and carelessly reversed polarity on reconnecting the controller after I decided to permanently mount it. I proved their ruggedability claim! After a short burst of fireworks and then reconnecting it the right way, it came right back and was fully functional. It really is idiot proof, and I proved it!

In a world where overpromise and underdeliver seems to be the corporate standard, it is refreshing to find a product that does what it says, and does it well. I've been using this for for over a year now, with a couple different configurations on my solar array, and it has performed with no problems, no mysterious readings changing. I have not needed to 'turn it off and back on again' to get it to work. It just does its thing and charges both of my battery banks.The only complaint I have, and it is not a strong enough complaint to take a star away, is that the advertised ability to adjust the settings does not really exist. In order to fine-tune it (i.e., lets say I wanted to adjust the max output by a couple tenths of a volt) you have to buy a $40 meterbus adapter. What's more, that adapter is RS232--while that was a common I/O port 20 years ago, good luck finding a computer with that interface these days. That said, it works fine for my needs out of the box and probably works for all but maybe one in a hundred customers who might actually need to tweak the default settings.

It's nice, I like the fact u can charge two batteries at the same time and choose which one gets the most power. Would have been nice to get this in a MPPT controller at 30amps. But that's fine, I'm Running this in my small fishing boat it's my tendering/charging system. I wanted to help the trolling motor battery the most, and the crank battery the least, so I have it set 90/10. My first time with solar so just playing around here. Two new batteries one a very large 75lb deep cycle marine the other a AGM blue top marine crank/deep cycle. It comes with a nice view meter for viewing the voltage mainly nice to see what's going on at all times while charging or while the batteries are hard it work out on the lake. You will have to installing "3" 30amp inline fuse! One on each battery and one close to the solar panel. It's possible to use the solar inline glass fuses they make for 8g wiring. And While being water proof. I shopped all over my town until I found a very large in line fuse made with with 8g wire. So go find and buy 3 of the glass inline mc4 style fuses and install them before u setup. And another thing, I hope u have plenty of solar panels or willing to wait on changing time because 2, 12v batteries will take a while to charge on just one,100watt panel. Your only going to get more of a tender if your not in full sun all day. U need the Maximum 10-15amp requirement for charging. And a Min of 2amps when tendering. So make sure u have plenty of sun hitting your panels all day or enough panels to get your max and min requirements. Or u may end up killing your batteries over time, as deep cycle batteries need to be topped off soon rather then later. All in all I really like this setup it really tops my batteries off to there MAX!! Without hurting them, which gives u more run time.PS: If I had to do it all over again I would , but I'd like to have a MPPT controller also. It blows my mind how much power your losing from your panel to your controller to your battery to your device or if your using inverter your losing a lot more. Quick math for u. 100watt panel your only getting about 80watts then take away about 30 more watts using this controller. So u roughly have a 50watt panel pretty much after all said and done. Then if your not staying in full sun all day.? Your not even getting much. Your just pissing in the wind total waste of your hard earned money. And when your using/running a inverter then it loses a ton of power that's about 30watts or more!! U end up with a 40-50watt panel for sure if your in the blistering hot sun.

works great, easy to install, but wire connections , could be a little larger. Worked great last winter when motorhome was stored outside. Didn't have to worry about batteries freezing, like they did the year before. Glad I spent the money,