HQST 60 Amp MPPT Solar Charge Controller 12V/24V/36V/48V Negative Grounded Controller with Built-in Bluetooth and Lithium Battery Low Temperature Protection Function, Support Two Units in Parallel

I needed a charge controller that could do 12v now but would be good for 48v later and this fit the bill. What can I say? It just works. Configuration was very easy. The display is clear and easy to understand. The device is solidly built. The battery terminals took 6AWG no problem.To test I hooked up two spare 260W panels and it charged the battery up in the expected time. As stated on the front of the case and in the manual, the array size is limited by battery voltage, and at 12v it'll use 900W of panels. I ran it with 1040W (120VDC, 4S) and it worked fine. I tried with more 2080W (4S2P). As expected, at 12v It didn't take advantage of it. Roll on 48v!In terms of battery types, when the controller arrived, the 100Ah LiFePO4 I had ordered to go with it had not yet arrived, so I tried with a 12v 7Ah lead acid. It charged up without issue and obviously quickly. When the 100Ah arrived I set the battery type to LI and it carried on no problem.I have since added a second 12v 100Ah and before setting it up in parallel I tried it out in series at 24v to see how the charge controller would do. It didn't auto-detect the new voltage in the way I expected, instead it showed 24v was connected, but blinked an LED until I set battery voltage setting to 24v. On reconnecting the panels the controller got right back to business.For monitoring, the ChargePro app connects to the controller via Bluetooth. The app refreshes status every other second, giving details on the incoming PV, battery and load ports if used (mine are not, the inverter goes to the battery directly). It also has a fairly basic historic data section and allows some settings / load port active status to be changed from the app. The Bluetooth range for me is about 15ft through a wall, which isn't great but good enough. There is an external Bluetooth adapter one can buy that may improve range. One surprise is that there is no pairing code required, so in theory anyone could connect, though again, they'd have to be pretty close to it and have some insider knowledge. The Bluetooth identifier can be changed to something else to obfuscate, and again there's not a lot to do in the app so in practice it's not a big deal.I've ordered a fuse box, some 12v USB ports and lights to hook up to the load port and eliminate having to turn on the inverter to charge phones and so on. The load terminals are easy to turn on and off via ChargePro or the controller itself. As the load ports reflect the battery voltage, going to 24/48V would need a DC to DC step down to continue using 12v stuff.It's a pretty resilient device and I have not managed to break it yet. Thumbs up. I'd buy it again.*UPDATE 11/22/23*I upgraded to 48V and the HQST is performing exactly as I had hoped. No problems at all charging 4 12.8v LiFePO4s in series. Just make sure to individually charge each battery to full before putting them in series so they are properly balanced. Using a 48v to 12v transformer for lighting on the load port.

I have purchased several of these controllers of different amp/volt capacities. They do a great job, and in some cases have even worked well enough to get a little more wattage out of my solar panels than they were rated to produce. I've run them in parallel with other units (same and different sizes) with great results as well.The Bluetooth connectivity is nice to have, but for me, seems a little low on the range with the integrated transmitter. They have an optional module to help with that if you need longer range. Still, it's a nice to have feature that lets you change all the settings without having to go to the actual unit and click endlessly on the buttons to program in what you want.I did have one fail recently a year into it's operation for unknown reasons. I reached out to the company to ask about replacements or service. They offer a one year warranty so that will be nice as far as refunds go. Should you buy or have one of these that fails inside the warranty period I would expect they would be as professional to you as they have to me. Naturally, they did want photo/video verification of the malfunctions, but that's no big deal.The customer service of HQST has been very kind and professional and their response time has been fairly quick. Typically, I hear back from them by the next morning during our conversations regarding warranties on failed units.These units are robust and rugged. While the internal components are encapsulated, the screen is vulnerable to water, so keep it safe from precipitation. Best practice, shield it from the elements and insulate its enclosure if possible.All in all, very happy with these units. Don't waste your time with PWM controllers unless you have a very specific, and carefully designed system. And, watch out for sneaky controllers that say MPPT when they are not (I managed to buy some of those which were quickly returned). These are the real deal.

I feel like a got a pretty good deal on this controller. It looks like it works well in MPPT mode, and puts out more power from my solar array than a PWM controller. I would give it five stars except that the terminals that are meant to hold the wires from the solar array and to the battery are very flimsy and don't hold the wires very well. The stripped wire fits inside a little square box of thin metal inside the hole, and when you turn the screw, the box moves upward, clamping the wire.I'm using 6 gauge wire since the array is up on the roof a little ways away, and the wires don't fit in the holes for them. If I strip the insulation so that the copper part goes in, since the holes are very close to each other, I have two wires carrying 40 A of current right almost touching with just the copper holding them. Since I have the controller mounted on a wall, the holes face downward, and the weight of the wires causes them to want to slip out of the holes, since the slick, flimsy metal clamp can't really grab the wire very well. Then you have two wires carrying a lot of current with bare copper sitting right next to each other.Why couldn't the holes be farther apart, and why didn't they use a sturdier clamp or have studs to attach the wires to?Also, the bluetooth app and features are very useful, but with the controller mounted right a couple of inches from the thin, single ply wooden wall of my shed and me standing outside the shed, I can only connect when I'm within about 3 to 5 feet. My living room window is only about 10 feet from the shed, but I can't get the signal there. My visions of monitoring my solar setup from the comfort of my chair next to the window have been crushed. I have to go outside and stand in my backyard next to the shed. I might as well just go inside the shed out of the weather and look at the display on the controller.