I purchased this to replace the regulator that came with my Harbor Freight solar system, after the regulator died. My system was one of the original ones, which came with a well built metal regulator. It lasted several years before giving out.This regulator is half the cost and far superior - plus it was a drop in replacement. It allowed me to connect my two sheds together and run from one battery. Very nice when getting in the sheds at night! I cut up a set of string lights and used 12V LED bulbs in the sockets, and just used two bulbs in each shed. This regulator keeps them burning brightly for as long as I need.It is quite "smart" and can figure out your load and battery type automatically. I use a small 12V AGM alarm type battery, which works great for my simple lighting application. If I forget to turn off a light, it will shut the load off when the battery gets low. My old regulator would just let the battery die, requiring me to replace the battery.It has now survived a Colorado summer and a winter in a very hot and cold shed, and is still running perfectly almost a year later. I couldn't be happier with this purchase.

I've had 4 of these in our RV for four plus years and these have been very reliable and effective. I'm about to order a fifth. Today I took one of my originals and hooked it up to four 305 watt panels in parallel and it put out 38 amps at 27v!I have these filling my 280 lifepo4 30ah cells in a 8s35p setup and they work great. I need controllers that let me dial in the charge voltage for lithium and these do that. I set them up for 27.6v and they never exceed it. Highly rated. Super reliable. No frills.I've also used one of these's light output for my 15a dc-dc converter which has powered our 12v system for like 3 years flawlessly.I've tried a few mppt controllers and they rarely put out more energy than these. Mind you I would not use a 39v panel on a 12v system as you'll not get much power out of it. It's best to have the panels just a bit higher voltage than the pack. With this controller you can dial the charge voltage all the way up to 34.0 volts - so I could extract a bit more power out of my panels by getting a bit higher voltage (like 9 cells in series) but I don't want to rebuild the 600 lb battery. Max volts on my aims 24v inverter is 31 so 9 in series would be good.

UPDATE:Over 2 years later and this is still working fine!ORIGINAL REVIEW:Just finished installing this solar controller on my 100W panel set up. I intend to power a 10W night light in a remote building and run a battery trickle charger for my ATV in the winter.After reading the reviews here, I was aware of the need to fully unscrew the terminal screws and then insert wire ends into the square opening, then tighten terminal screws, thereby pulling the wires upwards. I re-used wires off another controller that had connectors on them, making connecting and disconnecting the battery and solar panel much easier.I connected the battery and the LCD display powered up as expected. I then connected the solar panel and started to get readings on PV amperage. The LCD continuously runs through a sequence of screens displaying the various parameters. The E0 parameter indicates that there are no errors. All is good!I long pressed the one red button and reset the now flashing "16" to "0". (all covered in the instruction manual). This is supposed to make the load circuit come on at dusk and go off at dawn. I assumed this triggers off the very low voltage from the solar panel (PV) at night. However, covering the solar panel and waiting the minute for the controller to change settings did nothing. There's no light sensor visible on the controller, but covering it didn't work either. What I found later was that the 1 min delay before the load circuit kicks in is much longer. I disconnected the panel, did some other things and on coming back, the load circuit was active. The canceling of the load circuit is about 1 min though.I connected a cigarette lighter outlet to the load terminals for a test and reset the "0" to "17" so that I had power to the "load" wires all the time, shown by a lamp symbol on the LCD display. I plugged in a 12V automotive hand vacuum. It ran fine. The LCD readings were worthy of note...The battery voltage with the vacuum off was shown to be 14.4V, 100% charged, PV 0.2A and load 0.0A. On switching on the vacuum, the battery voltage dropped to about 12.2V, 33% charged, PV 6.0A and load 7A. As soon as the vacuum was switched off, the previous no load numbers began to reappear.I checked the battery voltage with the solar panel disconnected and the LCD showed 12.6V. My multimeter read 12.8V. I reconnected the solar panel and the battery voltage went up to 14.4V on the LCD and 14.6V on the meter. Consistently, the LCD was 0.2V less than the multimeter. The amperage readings are more accurate.So, it looks like the battery percentage correlates with the battery voltage at the battery terminals, which will depend on the voltage being applied by the controller from the solar panels. With power from the panel, the voltage will be higher than when there is none. After 30 mins or so at night (after the battery has time to settle down after a charge), the battery percentage and voltage should read the actual state of the battery. I will have to confirm this tonight and update the review accordingly.The night time check seemed to confirm this.The LCD's PV amperage seems to be the actual current being pulled by the controller to supply the battery. It was reading 0.2A with no load on the battery, but the max. 6A (bright overhead sun) when the vacuum was running. So, the charged battery was receiving a low trickle of just 0.2A.The battery percentage didn't correlate well with the battery voltage reading when under load. 12.2V on a lead acid battery is about 60% charge. (>12.6V is fully charged), not 33%. When I covered the solar panel, the battery voltage slowly settled down to 12.6V. The battery charge percentage was now 96%. It should have been 100. Obviously not a very reliable parameterSo far, everything seems to be working as it should.I hooked up my inverter to the "load" circuit and charged my ATV with a Battery Tender overnight. This morning, the ATV was on a trickle charge of 0.1A with 0.2 PV amps. With the load removed, the battery was at 12.4V/78% per the LCD, but we know the voltage is closer to 12.6V and so still nearly fully charged. After an hour, the battery was at 12.9V/100%.The USB port seems to be set up as a "load". So it is only powered if the lamp symbol is showing. I had to reset to "17" from "0" for a daytime phone charge during a power outage this morning. It's a 1A output, so not a "fast" charge. However, using the inverter and the phone's fast charger gives that functionality. With one phone on USB power and one on the inverter/fast charger via the "load" terminals, the battery was at 12.2V/63%, PV 0.8A {with an actual measured PV voltage of 12.4V and current of 0.83A under overcast noon conditions} and load of 1.2A. During this, the temp readout increased from 19C to 30C, though the controller didn't feel warm. As greyer clouds came over, the PV dropped to 0.3A and the battery voltage to 11.9V. 30s or so after the load was removed, having charged the phones, the battery was at 12.2V on the LCD. FYI: It looks like on a rainy cold cloudy day, the 100W panel produces between 4 and 10W {maybe 20 to 50W per day}The big question is whether this unit is reliable to keep going for good length of time. So far, so good.

Purchase 1 for my new 200W solar panel, cut the required hole in exactly the best spot, and it slid right in and flushed out with my cab. side panel as hoped.Wired it up very simply as directed (piece of cake, so easy, you can’t go wrong) and mounted it permanently.Works as designed so I couldn’t be happier. Digital readouts are right there to confirm the numbers I need to see anytime it’s necessary. 👍🏻😎

Bought this to charge sealed universal lead acid batteries. It works great as long as the battery has enough voltage and the solar panels are putting out enough amperage. I was getting an error 3 (E03) message a few times with a smaller 12v solar panel that was only putting out a max of 200ma and it didn't seem to pick it up, so its meant for bigger panels. With that said, it's fantastic how well these keep my lead acid batteries trickle charged. I just leave it in the window and swap out batteries when I need to. Would buy again, but I do not need to!

Habe das Teil seit gut 3 Monaten ohne Unterbrechung in Betrieb und bis jetzt keinerlei Probleme feststellen können.Für kleine Annlagen sehr gut zu gebrauchen.

Like my other review on the solar panel I have this connected to. Had this for a few years now and it's not rated for water, but gave it a chance and it's still kicking strong. 13.9v at full sun to get my boat battery up to top condition without a problem. Even had it running without battery and was able to get 75% thrust on 65 thrust motor(Don't try that at home unless you are willing to try your motor) Can't go wrong at this price point, going solar on everything at this point. Free energy :)

Hay instrucciones en español?

So far only basic testing for a solar panel/light application that is not installed yet. But seems to be performing properly through testing so far......

Not suitable for what i needed.