HQST MPPT 20A 40A 60A Lithium Solar Charge Controller Review

Introduction to hqst MPPT Controllers

greetings I'm Professor hobo and welcome to another hobo Tech news product reviews I get approached all the time to review solar controllers and I almost always turn them down because they're either obvious junk grossly overpriced or Worse both however hqst asked me to check theirs out and I was very pleasantly surprised by the features build quality and low low price they're offering So today we're going to check out what is claimed to be one of the best bang for the buck MPP solar controllers on the market but is it any good let's find out

Model Variants and Core Specifications

first this comes in three flavors 20 amp 40 amp and 60 amp this is the 60 amp version now three of course are mppt controllers because I wouldn't waste my time testing junkie pwms so let's go over some of the numbers the 60 amp supports 12 24 36 or 48 volt battery Banks the 20 and 40 amp versions only support 12 or 24 volt batteries the 60 amp supports up to 900 watt of solar at 12 volts 1800 watts of solar at 24 volts 2600 watts of solar at 36 volts and a whopping 3200 watts of solar at 48 volts the 40 amp supports 600 watts and 1200 watts at 12 and 24 volts respectively the 20 amp supports 300 watts and 600 watts at 12 and 24 volts respectively now the 60 amp does support a higher solar panel voltages so this supports up to 150 volts of solar input the 20 and 40 amp version support up to 100 volts of solar input now the VOC is on every solar panel it's the number that you look at to determine the max voltage that you can pump into one of these controllers don't go by 12 18 or 24 volts you have to go buy that VOC number this means if you add up all the VOC of the panels you plan to place in series you got to make sure that total number does not exceed 150 volts on this controller

Key Efficiencies and Load Management

now what about hookups on this the 20 amp has 10 gauge terminals the 40 amp 7 gauge Terminals and the 60 amp 6 gauge kernels because of course the more power you put the larger wires you need to use now all three models do have 99 mppt tracking efficiency and a 98 Peak conversion efficiency self-consumption is only 10 to 12 milliamps on the 12 to 24 volt models and as low as 2 milliamps in 48 volt mode when you're running the 60 amp version of course these all have load control built into it like just about every other solar controller it allows you for running small loads directly off the battery and controlling it either remotely via app via daylight sensor or with a daylight timer

Now on to the features there are three major features on these hqst controllers and these are why I chose to do this review is it's hard to find this feature set at this low of a price point

Advanced Features Overview

Low Temperature Charging Cut-off

first and very important to some of you they support low temperature charging cut off meaning if you have an unheated lithium iron phosphate battery that does not have built-in low temperature charging protection you can tell this controller to not charge them in below freezing conditions this is a really big deal to a lot of folks that charge lithium batteries in cold weather conditions an hqst even includes a remote temperature sensor in all three versions of this for that exact purpose

Activating Low Temperature Protection

so this feature does not come activated by default which means it is disabled so unless you turn it on it's not going to stop charging your batteries below freezing so let me show you quickly how you turn it on okay first thing you want to do is hold the gear icon that takes you into the settings you want to make sure you are on the LI or lithium profile for this to work because obviously you don't need it on other profiles continue to hit the gear icon until you see the word off dot f now all you have to do is up or down arrow turn that on hold down the gear icon to get out and when you're finished and you back out you want to go through and make sure that your setting has taken because I've noticed sometimes if you don't hit the buttons just right it's not going to save your settings so there it says on dot f that means that the low temperature protection is turned on

Real-World Low Temperature Test

now let's prove that the low temperature protection actually works I do have some Icy salt water here and I have the probe inside it's registering the temperature at 29 degrees there it is it says 29 degrees Fahrenheit and it is not charging it is not accepting a charge in fact even on the screen here you see a little solar panel there is no transfer of energy going to the battery I'm going to remove the probe from the Ice Water watch the temperature go up and we'll see that the charging starts you'll see this number tick up and then the animation will begin so I'll have to do is get this to warm up a little bit okay as soon as we started warming it up it says 42 degrees the charging is now back you can see the little animation Arrow there let's just do this again I'm going to stir up the salt the most of the salt is in the bottom of this it didn't dissolve see if we can get it down below freezing again and get it to shut off I notice it does take a few seconds for it to register the temperature and actually activate or deactivate the charging now obviously temperatures aren't going to drop this quickly in nature they're at 28 degrees so it does take about a minute for it to register that it's below freezing and we'll shut off the charging and there it goes it just as soon as I zoomed in it stopped the charging and like I said that delay is not a problem in real life because the temperature is never going to drop that quickly outside or even rise that quickly outside so a minute is more than enough time for it to stop charging before your battery gets destroyed

Parallel Communication Capability

next these actually have the ability to parallel with each other and communicate settings and charging parameters this means that you could buy the 20 amp controller right here today and if you added more solar panels in the future you can get another 20 40 or even the 60 to add on to it and by using a simple six pin rj12 which basically it's a six pin telephone cable for those of you that remember telephones that you plug into the wall it uses this as a data cable to communicate the settings together and all of the solar controllers have this input on it so all you have to do is plug the cable into both sides but then you have to enable this setting and this is not mentioned anywhere in the manual it was really confusing to me I wasted a bunch of time trying to get these things to talk to each other but I went to their website and there's a video that explains how to do it but it is not mentioned anywhere in their user manuals

Parallel Setup and Bluetooth Integration

Enabling Parallel Mode

now in order to activate the parallel feature you have to do a special butt combination so first and third buttons hold them down simultaneously and it comes up with pr-0 zero turns paralleling off so what you want to do is use the up or down arrow to change that to a one press the gear icon now that should save the setting but we need to go back in there and make sure okay it does save pr1 and then you need to do the exact same thing on the other one pr0 change it to pr1 gear icon and boom we'll just double check okay it is pr1 and now that you have paralleling turned on for both and you do have the cable going between them it will now communicate the settings from one to the other

Master-Slave Dynamics and Configuration

now there's an important thing to realize that one of them is going to be considered the primary and the other one is going to be considered the secondary now the only way you can tell is by looking on the screen so one of these two screens are going to have a tiny little icon in the upper right hand corner and that tiny little icon so happens to be on the 20 amp model now this means this is the slave and the 60 amps going to be the master so any changes I make here going to be automatically reflected over here so let me demonstrate this so let's go ahead and change it from lithium mode to gel for example hold down the gear icon now you do have to wait a few seconds for the information to transfer over to this one but let's go ahead and hit the gear icon it says it's set to gel and just to show you that I didn't cheat on that it actually does send the settings over we'll put it back to lithium so wait a few seconds oh man it switched it on me now here's something that I've actually caught ran into a few times before there's a little bit of a bug where sometimes they'll switch on you now this one actually has the icon which makes this the slave and this one the master and I think it's because I change the battery type and I think that's what actually causes it to switch from slave to master but anyway I changed it back to lithium there give it a few seconds it should show up here as lithium yeah okay and it is now unfortunately there is no way to force one or the other to be slaver Master it just seems to be random I tried turning this one on first then this one setting parallel to that first and this one unplugging re-plugging the cable I spent probably 30 minutes trying to figure out is there a little scheme that I could use to force it to use the 60 amp because it always seems to favor the 20 amp and I don't know why that is you think it would favor the largest model and use that as the master and this is the slave but every time I hook these up this will be the master first and then after I make a couple settings changes it'll switch to this and permanently basically stay there so now it's going to be permanently set this one to slave so you had to make all your changes on this one

Integrated Bluetooth Connectivity

and that brings me to the final feature that I liked about these unlike most solar controllers that require an external module for Bluetooth it's actually built into the hqst models that's the 2040 and 60 amp versions all have built-in Bluetooth now that does mean you need to know which one of these are slave or Master when you're changing the settings via Bluetooth because if you try to change it on the wrong one those settings just won't take they'll just be ignored so you have to pay attention to that little icon so you you know okay this one's the slave you need to Bluetooth to this one and change all the settings on this one and then it'll automatically transfer over to the other one

Using the hqst Mobile App

now what's cool about the Bluetooth it means you can control the major settings and remote monitor your controller wirelessly via their app within Bluetooth range which is about 30 feet so let's take a quick look at that app now when you open the app you need to go in and connect directly to the Bluetooth now the first one it says charge Pro that is the 20 amp and then the one down here it says PV charge Pro that's the 60 amp so since we know this is the master that's the one we want to connect to so you can see here it says real-time monitoring gives you the battery stated charge and the voltage gives you the amount of solar input which right now is zero because I don't have it turned on gives you the battery voltage and the current and the DC loading now you can store up to 300 days of historical data so you can see on the screen it'll show you the maximum minimum voltage or charge rate and everything else over the last 300 days now as for the parameter settings you can just hit the parameter down here in the corner this allows you to change everything in here including the battery type and all your charge parameters so you can go ahead and customize this as much as you like and then this will allow you to change your Boost voltage up or down depending on your needs then if you hit confirm it'll actually automatically send those settings to both controllers and that's really all there is to it

Additional Functionality and Performance Testing

User Interface and Protection Features

now as for the other features this does offer a nice LCD display with straightforward easy to use buttons you've seen me get through the menus pretty easily and you can set this up without even using the Bluetooth app and not even tearing your hair out of course it supports all battery types such as flooded sealed AGM gel and lithium iron phosphate now this will automatically jump at dead lithium iron phosphate battery so if you accidentally kill your batteries at three o'clock in the morning they'll restart automatically as soon as the sun comes up these also offer a plethora of protections to protect this and your battery Bank those would be typical overcharging over discharging overload overheating short circuit and reverse polarity protection hqst offers a 12-month warranty across their mppt product line

Performance Testing Methodology

now this wouldn't be much of a secret lab without a little bit of testing there's not really a lot you can do with the solar controller besides pump power into it and see if it charges the batteries properly so what we have right over here is my variable voltage charger and I actually have another variable voltage charger over here so I'm going to use this to pump power into this and I'm going to use this to pump power into this I have a completely dead or almost completely dead lie time 100 amp hour battery behind me that's going to allow me to pump the most power possible end of the battery so we're gonna see can I get 900 watts or close to 900 watts into that battery through my variable voltage charger going through the HQ St 60 amp this supports a maximum of 900 watts at 12 volts so I'm not going to test 24 36.48 this is just a demonstration show you that it can pump in a lot of power it does work in parallel mode I've already done the pre-testing so I can guarantee it's going to work but I'll show you how it works

Parallel Charging Demonstration

so unfortunately it's kind of difficult to film both of these going at the same time but I'll go ahead and angle this in such a way that you can see the voltage and amp that I'm putting in over here so let's start with pumping the power in from this side because this is going to be the big charger over here now this little 20 amp only supports 300 watts now I do have this set to 100 volts DC and I'm allowed to put as many amps as it dang well pleases through the controller and into the battery now one thing to note when you're in parallel mode you have to supply solar to both controllers right now I have 100 volts pumping in you see this says zero zero amps because until I turn this on it thinks that solar is not being applied to both because these are set in parallel they want to work together therefore they both need some level of soul now you can put 10 watts in on this one and a thousand on the other one doesn't matter it just needs to be activated so I'll turn it on I have it set to 32 volts which is its maximum and now it's showing the green light on here that shows that it's solar charging and boom this green light just came on right before your eyes beating It Solar charging look at the voltage went way up so now it's actually supplying 14.3 volts into the battery and you can see down here here we have it 100 volts at 9.2 amps so we're actually pushing 920 Watts into the battery that's actually a little bit more than what it's supposed to do which is a nice little overhead even tells you right here 900 watts is the maximum so I don't know if you can read this or not but it does say 900 watts is a maximum for 12 volts 18 or 24 2636 and 3200 for 48 maximum charge current 60 amps maximum load current which is coming out of here 20 amps now that we're charging let's go through this now there is a slight backlighting to this so you can use it at night and actually see what it is okay there we go we have our 100 volts going in you see it's got a little animation going there showing you that the solar is going into the battery so it actually even tells you the current temperature of the sensor which is room temperature right now telling you how many Watt hours we've pumped into the battery until you hear the actual amps were pumping so we're not pushing 60 amps but we are doing about 43 amps

Maximizing Charge Output

now here's one of the things I can do to slightly cheat a little bit I'll go ahead and I'll change the voltage in the control or to allow me to pump in more power so I'm going to go into parameter settings and change the Boost voltage to 15 volts now it's actually pumping 15 volts into the battery so let's see we should actually be back in a pretty good place amp wise there we are we're pumping 62 amps out of a 60 amp controller and look we're doing 970 watts of charging that is fantastic so this controller over here let's go ahead and crank the amps all the way up and see what happens we're getting close to that magic 300 watts aren't we we're actually at 310 Watts because you multiply amps times volts so there you have it I'm pumping in 900 from One controller and 300 from another so I'm actually pumping 1200 watts or close to 100 amps into that battery which is its maximum charge rate anyway

Critical Wiring and Safety Considerations

now I don't want to do this for very long because the cabling I'm using you could see here is very flimsy and I'm just using battery clamps in fact I can feel the heat through there let's go ahead and let's go ahead and mix this test before I start belting cables but that's proof of concept yeah I can smell things melting I just set this stuff up temporarily you have to understand I work on several projects at once so I clear this table put something else do another video bring this stuff back hook it back up because I'm working on several videos at once a lot of times I'm just using flimsy cables just to demonstrate because I'm only running it for a few seconds now obviously you're not going to use battery clamps and thin wire like this on a 60 amp controller it will melt and probably cause a fire so don't go by my example don't be using batter clamps and cheap cables use the best wire you can afford look in the man you know the man will actually tell you what gauge wiring you should use and that's a big problem because I've actually personally known several friends of mine who wire up some big monster 60 amp controller like this using little skinny wires and they wonder why their performance suffers or their inverter turns on or off or they smell smoke or things melt or fuses blow it's because they're not us

hqst MPPT Solar Controller Technical Specifications

Frequently Asked Questions

Q1: Do all hqst MPPT controllers support 12V, 24V, 36V, and 48V battery banks?

A1: No, only the 60 amp version of the hqst MPPT controller supports 12V, 24V, 36V, and 48V battery banks. The 20 amp and 40 amp versions only support 12V or 24V battery banks.

Q2: Is the low-temperature charging cut-off feature activated by default on hqst controllers?

A2: No, the low-temperature charging cut-off feature is not activated by default. It is disabled out of the box and must be manually turned on through the controller's settings, ensuring the controller is set to the lithium (LI) profile first.

Q3: How do hqst controllers handle multiple units in a parallel setup, and how do I determine the master controller?

A3: hqst controllers can parallel with each other using a simple six-pin RJ12 data cable to communicate settings and charging parameters. One controller will be designated as the primary (master) and the others as secondary (slave). The master controller is identified by a tiny icon in the upper right-hand corner of its screen, and all setting changes should be made on this master unit. The master-slave designation can sometimes randomly switch, especially after changing battery types.