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SmartSolar 150/100 MPPT Acting Strangely after swapping to 48v system

NArnold

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Apr 1, 2022
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I have a problem that I can't wrap my head around. I have a SmartSolar 150/100 MPPT that has been configured for 12v. I recently purchased a 48v inverter and reconfigured my 12v battery bank to 48v.

I am seeing really strange behavior in the MPPT charger. The unit will bulk and absorb charge fine most of the time, but it will not put any current into the battery when it switches to float mode and the voltage drops well below the float setting.

Sometimes in the morning when the unit starts up for the day it wont charge while in bulk mode. The MPPT controller did this again today. My battery voltage was at 51v and I had 75v on the Panels. I went into the charger settings via bluetooth and disabled and re-enabled the unit and it started charging in bulk mode again.

I have been fighting this for about 2 weeks now and don't know which direction to go.

I am wondering if I don't have enough PV voltage for the unit to function properly. When configured for 12v I had 2 panels in series which was around 50 volts. With the 48v battery configuration I only added 1 more panel in series for a total of 3 panels in series which gives me 75v. I could add a 4th panel to the series string but would rather not at this time. I have 9 200w panels and would like to do 3s3p, I hope that's how to say that.


I have SOK rack batteries ordered so the bulk mode will be set too a lower voltage, which I hope will give me a little more head room with the 3 series strings.

Also when I switched over to 48V there was a firmware upgrade. The MPPT is now at v3.07. I did some searching and could not determine if that is actually the latest version of software. When I hit search for update it says the software is up to date.

I hope I didn't fry the unit when I hooked up the positive lead of the battery connection it sparked and popped. I did not think to use a resistor to charge the caps.

I always connect the pv panels last when powering up the unit and disconnect the pv panels first when powering down the unit.

I do have the MPPT hooked to a RPI via ve.direct connection, I don't think this is the problem. I have disconnected the PI with no luck.

I am also wondering if it just takes time for the unit to get use to the new setup, in the manual I think it states it takes 5 days for the unit to calculate its power curves.



My settings:
48v settings.jpg



Thanks for all the help!
Nick
 
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I have a problem that I can't wrap my head around. I have a SmartSolar 150/100 MPPT that has been configured for 12v. I recently purchased a 48v inverter and reconfigured my 12v battery bank to 48v.

Beast of a controller for so little PV...

I am seeing really strange behavior in the MPPT charger. The unit will bulk and absorb charge fine most of the time, but it will not put any current into the battery when it switches to float mode and the voltage drops well below the float setting.

IMHO, you're re-bulk is too low. I use 1.6V for my 48V system.

Please include all settings including those under "expert"

Sometimes in the morning when the unit starts up for the day it wont charge while in bulk mode. The MPPT controller did this again today. My battery voltage was at 51v and I had 75v on the Panels. I went into the charger settings via bluetooth and disabled and re-enabled the unit and it started charging in bulk mode again.

I have been fighting this for about 2 weeks now and don't know which direction to go.

Odd. Might be v3.07 related. I recall a few posts about concerns with 3.07.

I am wondering if I don't have enough PV voltage for the unit to function properly. When configured for 12v I had 2 panels in series which was around 50 volts. With the 48v battery configuration I only added 1 more panel in series for a total of 3 panels in series which gives me 75v. I could add a 4th panel to the series string but would rather not at this time. I have 9 200w panels and would like to do 3s3p, I hope that's how to say that.

Not an issue. Victron MPPT require Voc 5V above battery voltage to initiate charging. To maintain charging, 2V.

I have SOK rack batteries ordered so the bulk mode will be set too a lower voltage, which I hope will give me a little more head room with the 3 series strings.

Also when I switched over to 48V there was a firmware upgrade. The MPPT is now at v3.07. I did some searching and could not determine if that is actually the latest version of software. When I hit search for update it says the software is up to date.

v3.10 is the most current.

1653327803335.png

I hope I didn't fry the unit when I hooked up the positive lead of the battery connection it sparked and popped. I did not think to use a resistor to charge the caps.

Pre-charge not needed on MPPT. Most 48V connections get a spark.

I always connect the pv panels last when powering up the unit and disconnect the pv panels first when powering down the unit.

Doesn't matter on Victron. Only reason to connect battery first is so the MPPT autodetects battery voltage. Once configured and attached to PV, PV will power the unit even if you remove the battery completely.

I do have the MPPT hooked to a RPI via ve.direct connection, I don't think this is the problem. I have disconnected the PI with no luck.

Are you running VRM with the RPi? If so, have you tried updating the MPPT through VRM?

I am also wondering if it just takes time for the unit to get use to the new setup, in the manual I think it states it takes 5 days for the unit to calculate its power curves.

Only refers to finding the max power point. Charging should work fine. It might not be optimal power until after the 5 days.


Recommend you
Turn charger off.
Reset to defaults:
1653328326113.png
Disconnect PV
Disconnect battery.
Reconnect battery to autodetect system voltage
Reconnect PV.

If that doesn't resolve it, recommend you try to get it updated to 3.10.
 
Beast of a controller for so little PV...
Yeah it is on a 48v but it was almost maxed out on the 12v system.


Odd. Might be v3.07 related. I recall a few posts about concerns with 3.07.
Yeah, I saw that also, but couldn't narrow down a version. I was able to set up a VRM account and upgrade it through the portal.


Pre-charge not needed on MPPT. Most 48V connections get a spark.
I didn't think it ruined the unit, but was still concerned.


Doesn't matter on Victron. Only reason to connect battery first is so the MPPT autodetects battery voltage. Once configured and attached to PV, PV will power the unit even if you remove the battery completely.
This is good to know. I was under the impression that it is not good to have a PV voltage on an MPPT controller without the battery hooked up. This assumption I had made me scratch my head on how a blown fuse or breaker or bms from the charger to the battery would work. It sounded like to me that during any of these disconnect scenarios the MPPT could be damaged.

Recommend you
Turn charger off.
Reset to defaults:
View attachment 95568
Disconnect PV
Disconnect battery.
Reconnect battery to autodetect system voltage
Reconnect PV.

If that doesn't resolve it, recommend you try to get it updated to 3.10.

So I reset the factory defaults multiple times, however I did not turn off the charger during the process.

There is not much sunshine left for today, but after upgrading and restoring the factory defaults the proper way I am able to get a little current flowing during float mode. There is so little sun that I had to drop all the voltages down to simulate the modes.

As far as the expert settings go I will post those if this doesn't resolve the issue.

Looks like I am out of sun for the next 3 days. :cry:

Thank you for all you help @sunshine_eggo
 
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I had the same controller until I realized my 3S panels in the cold were tickling the 150Voc limit... Lazy demanded that I get a 250/100.

Hopefully the reset and the firmware update get you going. If not, I would conclude the unit is malfunctioning.

The "battery first" is important to old PWM controllers and some cheap MPPT, but it's mostly an outdated issue for MPPT sold today.
 
Well, I had some sun this afternoon and the mppt is still not functioning properly. I was able to find older firmware versions to re-flash the controller with but no luck.

I talked to the distributor that I bought the unit from and they said it needed to be sent back for testing, then they would warranty it if it is bad. I bought this on amazon and I am a little hesitant on sending it back to them. I am not sure if this is normal procedure. I read on another search, that screen shots are sufficient to prove the unit is faulty. It does kind of work if I enable and disable it. Not sure what to do, I am kind of disappointed in the unit. I have read nothing but good things about Victron and there equipment seems to work great, but as I searched the web for trouble shooting, I have found multiple threads with similar problems. I am convinced this is a software issue, since it will charge some of the time. Very frustrating!

The company said that I should try a hard reset, which is just leaving it powered down for a hour. hmm.......

I did this and the mppt did start a new day, so maybe it will work, but I am not too hopeful. No more sun today so will have to check tomorrow.
 
I have two Victrons a 75/15 in my RV for years and now a 250/70 charging my home. I love them. I don’t know about that hard reset. Because I removed my 75/15 from power for months. When I hooked it back up the other day all the perimeters were exactly how I had them set before.
 
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