diy solar

diy solar

HQST MPPT 40amp Charge controller.

flammafeuer said:
Are you using an Li battery? If so, what settings did you use?
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Yes, I am using LiFePo4 batteries, SOK 100aH and a Rebel 50aH, for separate applications. Here are my user settings so far. Note: screenshot is from the bluetooth app for the HQST 40A charge controller.
 

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AstroBob said:
I have been looking at this on amazon: https://www.amazon.com/HQST-Controller-Negative-Bluetooth-Regulator/dp/B09J16G1LV

Seems like it could be a good deal for a cheap MPPT controller? Anybody know anything about it?

It's like $99, and has bluetooth.

Is this Junk?
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I bought one just in case one of my Rich solar 40 amp controllers takes a dump. I hooked it up and tested it. It seemed to work fine. The Bluetooth and app are okay too. I didn't see anywhere to change the password though. The Bluetooth doesn't have a very long range, but that's not a problem for me. Does that help? I only run 12 volts so I don't know how it does on a 24 volt system.
 
Minimoose said:
I bought one just in case one of my Rich solar 40 amp controllers takes a dump. I hooked it up and tested it. It seemed to work fine. The Bluetooth and app are okay too. I didn't see anywhere to change the password though. The Bluetooth doesn't have a very long range, but that's not a problem for me. Does that help? I only run 12 volts so I don't know how it does on a 24 volt system.
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Thank you. I have had mine since march. As I said earlier, I haven't had any issues yet. Yep, I have noticed the rather short range for the bluetooth.
 
AstroBob said:
Yes, I am using LiFePo4 batteries, SOK 100aH and a Rebel 50aH, for separate applications. Here are my user settings so far. Note: screenshot is from the bluetooth app for the HQST 40A charge controller.
Click to expand...
I'm slowly reducing the Boost voltage on the HQST controller to see if there is a way to eliminate the E02 error on my Weize LFP that way. Do you have any thoughts on your batteries? If you could, what battery would you go with? I wonder if I'll find out that I just can charge the Weize as hard as other batteries. I got the Weize for its BMS, though, which was supposed to handle low temperatures well.
 
flammafeuer said:
I'm slowly reducing the Boost voltage on the HQST controller to see if there is a way to eliminate the E02 error on my Weize LFP that way. Do you have any thoughts on your batteries? If you could, what battery would you go with? I wonder if I'll find out that I just can charge the Weize as hard as other batteries. I got the Weize for its BMS, though, which was supposed to handle low temperatures well.
Click to expand...
I am unfamiliar with the E02 error. I haven't experienced any errors yet with my setup. I can only speak to my experience with my rebel 50aH and the SOK 100aH. They have both been trouble free for the period I have had them. (1 year rebel, 4 months SOK).

I see from the manual that the E02 error is defined as:

"Battery voltage has exceeded controller limit.
Check battery bank voltage for compatibility
with controller"

That seems strange. What battery have you connected to?
 
AstroBob said:
I am unfamiliar with the E02 error. I haven't experienced any errors yet with my setup. I can only speak to my experience with my rebel 50aH and the SOK 100aH. They have both been trouble free for the period I have had them. (1 year rebel, 4 months SOK).

I see from the manual that the E02 error is defined as:

"Battery voltage has exceeded controller limit.
Check battery bank voltage for compatibility
with controller"

That seems strange. What battery have you connected to?
Click to expand...
I am using a Weize 50 Ah LFP. Another user is messaging back and forth with me, and suggested setting the Boost voltage lower, which I have done (down to about 14 Vdc). I am now able to get to the Float phase, which I have set as 13.3 Vdc.
 
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flammafeuer said:
I am using a Weize 50 Ah LFP. Another user is messaging back and forth with me, and suggested setting the Boost voltage lower, which I have done (down to about 14 Vdc). I am now able to get to the Float phase, which I have set as 13.3 Vdc.
Click to expand...
I am curious what the boost voltage was set to. I have mine at 14.4
 
AstroBob said:
I am curious what the boost voltage was set to. I have mine at 14.4
Click to expand...
I presently have my set to 14 with a float of 13.3, and things are stable. Will try increasing the voltages from there...I'm not too happy if I can't do 14.4, the recommended charge voltage.
 
Something seems amiss here, the boost voltage for my two stand alone lifepo4 chargers is 14.4 and 14.6 respectively. Are you able to charge with a dedicated charger?
 
Here are a few:



I own the first one. The others are highly recommended by many, but a little pricey. I also have a cheap 5amp that charges at 14.4 boost.

this is the el-cheapo 5amp.It does work
 
I bought your cheapie one for now. I finally heard back from the vendor, and they gave me a link to the Genius, also. I've also seen those at some RV parks, so that might be the next buy.

So, something I missed, that someone else mentioned in a conversation is that this battery was drained almost fully when I left a small inverter and lights on it overnight. I then had charged it normally after. They were wondering if the cells were not equalized, and if I needed to let the BMS take care of that slowly. I'm pretty sure I experienced my E02 issue before that, but, it's long enough ago, I can't be sure. In any case, I experienced an issue at 14.1 Vdc this morning, and so changed Boost to 14.0 VDC.

When the charger gets here, I'll use that to charge the battery and see what happens.
 
In theory, the BMS should take care of the balancing. If it's a sealed case, that would be the only way. One cycle down to 0 shouldn't seriously damage the battery, the BMS should have a low voltage cutoff anyways. it sounds like you have something else going on. Is the battery covered by warranty?
 
So, I got the Moringe battery charger, set it to LFP, and in 30 seconds it reported the LFP battery as charged, no errors. So, whatever settings I have with the HQST must be getting it very close. I'll continue tweaking it, but, if I were to just trust this battery charger, I would think I've got a working LFP battery.

So, I'll keep trucking. Thanks for all the thoughts on my situation! Would be interested in seeing a visual of your setup, or schematic.
PXL_20220528_201811846.MP copy.jpg
 
If you run your
flammafeuer said:
Hi, I'm having a very similar experience with my HQST, is it an E02 error? I also tried a PWM controller on my Li battery, and got a similar error. I have the HQST 40A. did you get a response from the vendor?
Click to expand...
If you run your panels in series for some reason the controller continues to do that. I have 2 because they sent me another but it does the same thing e02. So i put the panels in parallel ad it works perfectly. I have decided the hqst 40amp mppt cannot work with series correctly.
 
Captain-Hook said:
If you run your

If you run your panels in series for some reason the controller continues to do that. I have 2 because they sent me another but it does the same thing e02. So i put the panels in parallel ad it works perfectly. I have decided the hqst 40amp mppt cannot work with series correctly.
Click to expand...
My guess? Mine works perfectly, but I have a four 100ah agm battery bank. With such a small battery your controller may be a little slow responding and overshooting the voltage when it is initially lining out or when it gets to the full battery with no where for the voltage to go. I have hooked up 600 watts in s/p with no issues, but lead acid can overshoot the voltage for a short while. I don't have any lithium batteries to try it on.
 
flammafeuer said:
I bought your cheapie one for now. I finally heard back from the vendor, and they gave me a link to the Genius, also. I've also seen those at some RV parks, so that might be the next buy.

So, something I missed, that someone else mentioned in a conversation is that this battery was drained almost fully when I left a small inverter and lights on it overnight. I then had charged it normally after. They were wondering if the cells were not equalized, and if I needed to let the BMS take care of that slowly. I'm pretty sure I experienced my E02 issue before that, but, it's long enough ago, I can't be sure. In any case, I experienced an issue at 14.1 Vdc this morning, and so changed Boost to 14.0 VDC.

When the charger gets here, I'll use that to charge the battery and see what happens.
Click to expand...
I know this is an old thread but i have 400watts panels and hqst 40 amp mppt with weize 100ah. When i wire panels in series i get the same e02 thing. No one at hqst seems to be able to figure it out. They sent me a second one, same issue. So i put panels in parrallel and it works fine. No more e02. Only with panels in series and only when at full capacity does it trigger 02. Every time
 
I revive this thread because I have the same problem.
I've come to the conclusion that it's the controller fault. I think it has something to do with the controller itself over heating.
Previously I have the exact HQST 40a. Pretty damn good controller compared to my Renogy 40a.
I have 4 100w in 2s2p. With the HQST, I've hot as high as 407w but mostly in the 320w range.
Runs great, NP except the BT is like shit. I move beyond 10ft and it disconnect. I bought it mainly for the BT.
Returned it and got the BougeRV clone 30a mppt(Sunwhale). The glass face version you see on Amazon. All these are probaly made by the same company. I got the 30a because I'm planning on going 24v so 30a mppt is plenty.
First day, runs great until 1pm,(BT range is good) then I get the error just like you posted.
"Battery voltage has exceeded controller limit.
Check battery bank voltage for compatibility
with controller".
I know there is nothing wrong with my setup as I've rans this for ages with 2 different controllers. Gotta be the controller.
I read in an Amazon review that the controller report a higher temp than actual. Maybe this is the problem.
I'm going run this again tomorrow and see if the same problem arise. It's getting returned regardless.
I will try this next.
If this fail, I might go back to the HQST 40a as that ran flawlessly minus the BT.
 
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