MPPT - Solar Charge Controller Image

MPPT - Solar Charge Controller

LiFePo4 battery voltage variation


I have a MPPT SmartSolar 100/50 with a LiFePo4 200ah 12V battery Voltage is constant when sun is covered and there is less sun, but voltage seems to vary more when sun is at its best and MPPT is in absorption mode with voltage sometimes hitting 13V which can turn of my skylight roof vent/ 12V fan at times. Would you know where the issue can come from? I have the base LiFePo4 battery preset configured on my MPPT regulator
Many thanks for your help


amajor asked
klim8skeptic commented ·

3 Answers

SmartSolar MPPT 100/30 output fluctuation since update to fw1.49 using VictronConnect v5.21beta5.

I just updated a SmartSolar MPPT 100/30 to firmware 1.49 using VictronConnect v5.21beta5 (iOS TestPilot says beta 5 but settings shows beta 4), the solar harvest starts fluctuating and also the DC voltage starts to show some disruption. The output will slowly increase and then suddenly drop to 0 after which it starts up again slowly. It would continue this cycle until the sun is down.

After the update, VenusGX showed a notification that there was an unsupported DVCC firmware so I updated the connected Phoenix MultiPlus 800 to FW 474. I also updated the ESS assistant. I have restarted every single component in the system, disabled DVCC to no avail. Eventually I removed the load and disabled feeding back into the grid to safeguard the battery because this was the only thing I could do to stop the DC voltage fluctuation.

I also have a BMV700 in the system which is already running latest firmware.

I did do a factory reset for the SmartSolar MPPT to no avail. Could something have gone wrong during the firmware update? It halted for a few second during the update process and then started over. Is there a possibility of downgrading the MPPT to a slightly older Firmware just to check?

This system had a perfect was working perfectly before, there were also no clouds in the sky that could explain the behavior.


wrietveld asked
KSmith answered ·

3 Answers

Wire sizing 75/10 for single panel on a boat

Have a Smart Solar 75/10 with a 100 W, 12V panel with a Imp of 5.7A. No shore power, no inverter. Just the boat's engine alternator.

What AWG wire size would you recommend for 2% V drop?

Panel to Control: 13' one way distance.

Control to Battery- 10' one way distance.

Control to Electrical Panel buses- 5' one way distance. Is this sized assuming all loads are turned on at the same time and go thru these wires?? That would be around 11A.


Ted Burke asked
Ted Burke answered ·

2 Answers

Help with Assistants to use AC2 as dumpload

If I connect my 1000 watt water heater to AC2 of my Multiplus 48/3000 and use the assistants in below screenshot, is it correct that it will do the following?

  • Start the boiler when above 70%
  • Stop the boiler when at 60%
  • Stop the boiler when overall load is above 2400 watts
  • Only start the boiler when overall load is below 1500 watts


I found this thread that I've used as reference. My system is Easysolar 48/3000 with BMV712 battery monitor running 14kw lifepo4 batteries and the reasoning is that I'll never need more than 60% of batteries for other vital loads.

Thanks a lot!

bigvt asked
bigvt commented ·

2 Answers

Can I use the MPPT with a small panel to maintain my gel batteries while not in use for long periods of time?

I have a setup consisting of 2 x 330Wp panels connected to a blue solar 100/50 controller to charge 2 x 190Ah 12 batteries. This setup is for an off-grid cabin that will not get use during many months (6-9). During these months, the 330Wp panels will be disconnected and stored. The question is: Can I use a small 20W (21.5Voc) panel to maintain the batteries topped during these 8-9 months via the MPPT charger?

fede_h asked
fede_h answered ·

2 Answers

BlueSolar 100/5 lifert bis 21Volt

Hallo, ich habe einen Multiplus 3000, und einen BlueSolar 100/50 an 2 LIFEPO4 ( 12Volt) angeschlossen. Der Multi lädt die Lifepo sauber (nicht über 14,6 Volt). Bei 14,6 Volt schaltet der interne Batterie Manager der Lifepo die Batterien ab. Wenn ich nun den Bluesolar dazu schalte und die Batterien voll sind geht die Spannung langsam über 14,6v, die Batterien schalten intern ab und die Spannung steigt rapide auf über 20 Volt an. Trenne ich die Solarpannels, geht die Spannung wieder zurück auf die Lifepo Spannung von 13,6V. Der BlueSolar steht auf Stellung 7 für Lifepo.was kann hier die Ursache sein? Ist es nicht so, dass egal was ist, der Ausgang des BlueSolar auf 14,2V begrenzt sein sollte? Gemessen wurde das ganze mit einem BMV 712 und 500A shunt. Die folgenden Bilder sind die Panells abgeschalten.



Skyfly asked
Skyfly answered ·

2 Answers

MPPT not charging during Multiplus absorption (DVCC)

Should DVCC allow the MPPT to charge when sun is available, even when the Multiplus starts a charge due to low SOC early on a sunny day?

I've found the Multi will still be in absorption and the MPPT will go to float, but decides not to bother with any output, even though it could.

If i turn the MPPT charge off and on (in Victron Connect) it will try to charge for a few seconds but quickly cycle through Bulk-Absorption to float and give no output.. Only when the Multi goes to float does the MPPT start charging.

I'm using DVCC, + Ignore AC, both MPPT absorption and float voltages are higher than the Multi's

Could it be overheating? Today was hot and the batteries showed a peak of 37 Deg C, or maybe an incorrect setting, I.e. reduce the Ignore AC charge to end after bulk, but that's not ideal until we have more solar?

Or a symptom of the MPPT adaptive charge, either way i thought DVCC should tell them both what to do, as the Multi decided to use the AC In mains to charge when there was enough sun to cover the end of the absorption phase :( ..?


VRM link:


Al asked
JohnC commented ·

3 Answers

ESS multi/mppt staying in float

I have a multi/mppt ESS setup that runs on a schedule with a 75% hard SOC limit and a stop at 80% SOC in the schedule.

Due to load the SOC hit 75% within a couple of hours during the night and reverted to grid as expected.

The inverter state was "float".

The inverter at no stage changed from float to bulk/absorption so when charging started it worked it's way to 80% and stopped.

Despite tons of PV available it trickle charged all day to a rather miserable SOC.

Any insight into why the inverter did not change to bulk/absorb?

We have identical installs and they all behaved correctly.

nickdb asked
nickdb commented ·

2 Answers

MPPT 75/15 nach Update defekt?

Hallo zusammen,

unser Laderegler MPPT 75/15, an einem 135Watt Modul, direkt an AGM Batterien angeschlossen, lief nach Installation ein Jahr völlig ohne Probleme. Seit ein paar Wochen hat das Gerät Aussetzer (lädt sporadisch nicht, Spannung Solar wird nur mit 12,7V angezeigt, obwohl gut 24V vom Modul ankommen)

- Die Batterien/Akkus haben wir geprüft, volle Leistung und Spannung vorhanden, auch unter Last

- alle Kabel Verbindungen geprüft

- vom Modul kommen über 24V

- alle Verbindungen getrennt, nach ca. 1 Stunde wieder in Betrieb genommen

- das Problem besteht auch, wenn die Akkus nicht voll sind (wie gerade im Screenshot). Vom 29 bis 31 haben wir ohne Landstrom gestanden, keine Ladung.

Wir haben den Verdacht, dass es mit dem kürzlich durchgeführten Update zusammenhängen könnte. Ist das Problem bekannt oder kann uns jemand helfen? Vielen Dank!

Hier ein Screenshot:


Joerg asked
douweb commented ·

3 Answers

configuring smartsolar 75/15 with 2x Multiplus 3kva/120; temperature sensors; inverter overloads

Greetings, this is my first post here, so hopefully this does not reveal me to be a complete moron. I recently set up a power system (VRM link) in my fifth-wheel camper consisting of the following:

2x 300 AH Victron Smart Lithium batteries,

2x Multiplus 3kva/120 inverters in 120/240 VAC split phase,

2x SBP-220s (one as a load disconnect and another as a charge disconnect, as there are multiple DC charging sources),

6x Smartsolar 75/15 MPPTs with a 200w/24V nominal panel connected to each,

Orion-Tr Smart 12|12/30 DC/DC charger,

BMV-712 with shunt,

VE.bus BMS, and

Cerbo GX with GX Touch 50 display

(I've included a picture of the system as well as a rough diagram of the connections as well -- I know the mounting of the MPPTs looks suspect but there is a large circular hole drilled in the plywood behind each for ventilation, and there are about three inches of clearance between the plywood and the ceiling above it)

The MPPTs are connected to a USB hub which, in turn, is connected to the Cerbo. Everything seems to be recognized just fine and I can see all the system parameters in both the Cerbo's menu and VRM. DVCC is enabled (see screenshots below).

I have the following questions:

1) The MPPTs' charging states did not appear to be exactly synchronized, so I set up a network between them. Then later I learned about DVCC and enabled it. What is the proper way to synchronize the MPPTs (and the inverters and Orion charger, if possible) in this configuration? As you can see in the VRM screenshot the inverters and the MPPTs are not in the same charging state. Did I screw this all up?

2) I do not have a temperature sensor currently installed, because I assumed that since the batteries measure their temperature internally that they would report this information to the BMS which would, via VE.bus, communicate it to the rest of the system. But now that I've looked at the cables I see that that there are only three conductors between the batteries and the BMS; perhaps one is ground, one is charge disconnect, and the other is load disconnect. I have the temperature sensors that came with the inverters but I do not have the one that is compatible with the BMV ( ) -- is there an advantage to getting the latter or should I just use one of the inverter sensors? Is there some other/better way to do this?

3) One of the goals for this system was to be able to function as a UPS for two 15 kBTU/hr air conditioners (one on each phase). The inverters are currently set up with "switch as group" unchecked because the trailer will sometimes have a 120/240 VAC connection and at others it will only have a 120 VAC (i.e., zero line-to-line voltage) connection. In this configuration with "UPS function" disabled, if I have the two air conditioners running and cut the AC input, both inverters will throw an overload. What then seems to happen is they make attempts to restart at 30-second intervals, and generally on the third attempt they're successful and the air conditioners start back up. If I instead enable "UPS function", I can cut the AC input and the inverters will maintain power to the air conditioners without interruption. However, in this case, the system will not recognize single-phase 120 VAC input so even when such input is connected they will continue inverting. They will only recognize the 120 VAC input if I disable "UPS function", but then the overload problems occur. What's bizarre to me is that whether "UPS function" is enabled or disabled, if I am running the system without AC input (i.e., inverting), I can start both air conditioners without overloads. The overload only occurs if the air conditioners are already running when the AC input is suddenly cut and "UPS function" is disabled. I have used a multimeter to measure the DC voltage difference at the batteries and at the inverters when I cut the AC input with the air conditioners running; it does not get even close to the "DC input low shut down" value, and there's no perceptible voltage difference between the batteries and the inverters (i.e., I don't think it's due to poor connections -- and all inverter and battery cables are 4/0). Is there a way to get the fast-switching that seems to prevent the overload from occurring while also retaining the ability to use 120 VAC and 120/240 VAC inputs interchangeably?

Any thoughts on any of the foregoing questions (or general comments/recommendations on the configuration or layout of the system) would be most welcome (I know the wiring is a bit of a mess; still finalizing things). Or if you're just generally facepalming at this setup please let me know that as well -- I'll take harsh feedback over burning up $15k USD any day!






Jersey Dirtbag asked
Jersey Dirtbag edited ·

0 Answers

630Ah AGM Bank to load with 100/50 and 75/15 mppt Settings

Hello, we do have a 630Ah AGM Lifeline Bank and we charge it with two mppt controller. 1 x 75/15 and 1x100/50

Whlie the mppt chargers have the exact same settings the 75/15 always goes in absorption/float very fast... shouldn’t go the two controllers in parallel in the different modes ?

Do the two controller need different settings ?

As lifeline advices us to charge with different voltages we adjusted the abs. and float voltage accordingly For the two controller.

SYValentin asked

0 Answers

Error # 28 'power stage issue' with SmartSolar 150/60-Tr

Our 150/60 mppt controller is triggering the error code #28 'Power stage issue' when the PV load approaches about 350W. I'm confident the controller is sized properly for the system, which contains seven, 100W SunPower Flexible panels wired in parallel in a 12V system, the panels have the following specs: Voc = 21.4V, Isc = 6.3A, Vmpp = 17.1V, Impp = 5.9A. I enjoyed using the nice new MPPT sizing calculator on the Victron site, thanks to whomever helped build that; the excel file is nice too.

Our controller operates fine at solar yield wattages below 375W but, we have yet to surpass 375W realm without tripping error #28, "Power stage issue". I've found little helpful information in the documentation and other online sources, including this repository. The documentation does state that the controller may be faulty. We have been able to clear the error by disconnecting the controller from both the battery and solar load. After that the controller does operate apparently normally until the solar load again approaches 375W, at which time, the controller will again trip error #28.

I'd like to better understand possible root causes to troubleshoot.

Our overall system, includes a Victron 3000W MultiPlus, a BMV-712 battery monitor, a Color control GX, and 300Ah of LiFePO4 batteries from BattleBorn.

If anyone has knowledge and experience with error 28 in an MPPT controller and can share with me possible root causes, I'd be grateful.


Alex Hanks

alexhanks asked
aws.paulo answered ·

2 Answers

MPPT 75/10 and MPPT 100/30 in Parallel?

On my teardrop trailer which has an MPPT 75/10 and one installed 100W solar panel, I want to add the ability to connect one or more solar panels if needed. So I got an MPPT 100/30 with the intention of replacing the 75/10. However, the 75/10 also has "load" connectors which the 100/30 does not, so I don't know what to do about those (??). Alternatively, I guess I can just ADD the 100/30 for the extra panels, but how would I connect that in parallel? CAN I do that? How should I wire that? Are the 2 MPPTs going to interfere with each other if solar panels are connected to both?

Thanks a lot for any help!


pforster asked
wild_thing answered ·

3 Answers

Smart solar 150/100 bulk blinking

Hi, I have a 1200 Watt solar system connected to a victron smart solar 150/100. I'm standing in full summer heat but I only get 700-800 watts. Now I saw blue bulk light is blinking once every 3 seconds which means charging is disabled? But it's charging, just not how it should. I restarted the mppt and measured my solar input, its 120 volts how it should be. My lithium batterys are only 70%full which my bmv 712 is telling my solar over victron smart network. Anyone got a idea?

Steven Mailer asked
Paul B answered ·

1 Answer

Multiplus and Smartsolar Victron Connect Settings for Blue Nova Battery

Just to confirm the battery related settings on the Multiplus Inverter





Default to 37.2V?


Default to 43.6V?


Default to 43.6V?



Battery Preset- USER DEFINED

Absorbsion Voltage- 56.2V ?

Float Voltage- 55.5V?

Equalization Voltage--- PLEASE CONFIRM, Dont think this applied to Lithium batteries, what should it be set to?

Automatic Equalization- DISABLED?

Temperature Compensation- WHAT SHOULD THIS BE SET TO?

Low Temperature cut-off- DISABLED



Nearly ready to fire up the system for the first time.



valleyokie asked
ejrossouw answered ·

1 Answer

Are 50vdc solar panels wasted on a 12vdc system?

Hi, I am just trying to get my head around this and wonder if someone can confirm it please?

For a 12-15vdc battery off grid system needing to charge through a charge controller via a solar panel array of course which the panels are rated at around 55Vdcmax.

With the cheaper Ebay MPPT controllers (link to example type bellow), they cut off the solar panels inputs if the solar panel voltages are above around 15Vdc, so effectively the panel would only charge the system when the panel voltage is within the 12vdc - 15vdc, effectively only for a VERY short time in the morning and again at sunset.

With a Victron charge controller like (link of example type below), to charge the 12-15vdc from the panels (55Vdc). Does the Victron charge controller cater for the full 0-55vdc from the panel or does it also have built in cut out solar voltage cut offs, resulting in the same issue as the cheaper Ebay charge controllers?

I guess I am looking to have some device which converts the 0-55Vdc to a more usable 12-15vdc range so as to charge the batteries. Is the Victron charge controllers able to do that, regardless of the voltage from the solar panels are producing?

Kind regards


John asked
spirou answered ·

4 Answers

Fighting Gremlins - Electrical Cutoff at 1:30 am

Honestly, vague title because I'm unsure where to even begin. We've been parked for a few days in Yellowstone National Park in the US. Historically we run 5-6 days on batteries alone (setup details below). Recently I completed a solar setup that I 'thought' was working well, or maybe currently think so? I'm not sure. After 2 days of being parked at Yellowstone in a relatively shady spot and arriving with full SOC of 14.59V on the Battle Borns, 'something' tripped in the system and shut me down. The Multiplus had a low battery alarm, the BMV showed 57% and something like 13.35V. The SmartSolar controller said that the battery voltage had dropped to 9.12V which is obviously well below anything a LiFePo4 battery should ever see. This tripped the battery guard, took me a little bit to locate the failure, initially thought it was the transfer switch because I've had a few issues with that. The battery guard appeared to have done its' job, albeit at the cost of the battery guard as the only way I was able to restore power was to bypass it. No apparent temperature issues, outside temp was 84F and inside the trailer was probably 78ish. Batteries are inside, under the main bed.

Fast forward another 30ish hours, we went to bed and night temperatures drop fairly rapidly. Around 1:30 am my wife woke me saying it was too quiet, she couldn't hear the fridge running. Pulled up the BMV app, it wouldn't load. Checked the screen of the device itself and it was shut off. Inverter was completely off despite being in "ON" position. Silly me, left the multimeter at home so I didn't have a way to manually read the voltage. First thing this morning, we packed up and left Yellowstone to run some errands including buying a multimeter as well as dump/fill the Airstream. Once solar started kicking in around 8:30 am, we started getting some intermittent functionality of 12V users as one would expect. The BMV eventually turned itself back on with a voltage of 13.05V, so not "actually" a low voltage or even 0% SOC. Air temp was chilly last night but not "that" chilly considering the batteries are inside, outside was in the 45-50F range while we were probably 55-60F inside.

As we speak, we're in an RV park outside Yellowstone connected to shore power to get a full charge all over again, but more importantly for cell service to connect to you guys and try to troubleshoot something. I've attached some photos as well - apologies in advance for the kabalsalat! I've tried cleaning up a bit, but definitely have room for further improvement.

Just not even sure where to begin troubleshooting because readouts have been looking normal despite the weird events. Solar this morning was 50ish watts in our shady spot in Yellowstone, ramped up to 515 watts or so once the day got a bit later and we were outside the park. Currently plugged into shore power and charging batteries at 1200W. Are there additional historical logs I can pull from either the BMV or the SmartSolar? The app-based readouts are pretty basic.

A bit about my system overall:
2003 Airstream
960W renogy panels, 6 x 160W each hooked up in Series-parallel configuration (two sets of 3 panels in series, then paralleled into the MPPT)
800 Ah BattleBorn batteries, 8 x 100 Ah each

BGA-225 battery guard
Multiplus 12/3000/120-50 120v VE Bus

Victron SmartSolar Charge Controller (150V 45A Tr)


Go Power! TS-30 30 Amp Automatic Transfer Switch (shore power & battery charge primary, secondary is from the inverter)





OleSimo asked
ee21 edited ·

1 Answer

More than 50A potential into a 50A controller?

Hi - and my apologies if this is a duplication of a question asked without my having found the sub-group MPPT controllers:

I'm having to replace my controller for my 2x360W Sunpowers, run in parallel, with blocking diodes on the + legs.

Voltage ~70, max, and current (combined) ~13, max, from these panels at full output.

The most - and that only once, briefly - I have ever seen is 50A output. Yet, in perfect conditions, I MIGHT get 60A.

Can I use a 50A controller safely?


Skip Gundlach asked
dazey77 answered ·

3 Answers

Smartsolar MPPT 75/15 Load turning off and on

I have a Smartsolar MPPT 75/15 and after updating to firmware 1.50 the load turns itself off then back on 1 second later. This occurs when I turn on the tv circuit and occasionally when the fridge cycles on. The total load output with everything running is very low, 5 to 6 amps. I have seen other questions with users having the same problem however I can not find if a firmware update is due to fix this issue.

Deano9 asked
dazey77 answered ·

3 Answers

Simultaneous MPPT and Fronius doesn't use all the PV to charge the batteries


Here is the configuration of Quattro 48/8000:

Fronius Inverter (7kW) on OUT1

MPPT (4kW) through DC-BOX on Pylontech Lithium batt

it runs under ESS Optimized (without BatteryLife).

I don't understand why the Fronius energy doesn't go to charge the battery ... here the problem :


1570W into the grid instead of charging battery...

how can we correct this behaviour ?

I can give you more details if necessary.

Best regards,


khaem asked
khaem commented ·

3 Answers

MPPT 75/15 ohne Bluetooth grüne LED blinkt

Hallo, ich habe vor 2 Jahren den MPPT 75/15 in meinen WoWa eingebaut. Seit kurzem lädt er nicht mehr und die grüne LED blinkt. ist der Laderegler kaputt? Wie kann ich das testen? Der Händler meldet sich weder telefonisch noch per email bei mir. Danke

Eulalia asked
ejrossouw answered ·

1 Answer

Disconnect solar when no battery

If I need to remove a battery from a system, when solar is connected, the circuit remains live so long as solar energy is available. Does the Victron charge controller (BlueSolar 75/15) have a feature whereby it switches off (effectively isolating the solar) if it senses that there is no battery?

andrew.g asked
Sportswagoneer commented ·

2 Answers

SmartShunt 500A/50mV


Since August 20, the new Victron SmartShunt 500A / 50mA built into my caravan to gain more insight into my 12V circuit.

The first thing that strikes me is the bluetooth signal is quite weak, especially compared to the already built PeakPowerPack 40Ah with bluetooth dongle and a Bleu Smart charger 12/5

The Victron app also displays a voltage of -0.01V in the starter battery field while no starter battery is present.

Are these software errors in the app?


Fendt 465 asked

0 Answers

MPPT 75/15 - Consumption - why is consumption high when there is no load?

Hi all,

I am new to solar and need some help. I have a simple solar set up two 300w panels, victron MPPT 7/15, victron phoenix 24v 250 inverter and two 140ah AGM batteries in series. Attached to the MPPT load I have a USB charger to power a mobile phone. I also have a blue tooth dongle attached to the inverter to link to the phone / app.

I have a breaker in between the panels and the MPPT and fuses between the MPPT and batteries and between batteries and inverter - all on the live wire.

When everything is off - no load on either the USB or inverter (inverter is switched off) the Victron app is showing consumption of 50Wh.



The system ahs been running for around 2 months. Initially consumption was no more than 40wh but in last week or so it has been over 100wh (but with load - laptop / two monitors c100w - 140w).

Questions I have are:

1. Is this normal / typical?

2. If not normal what could be causing it? Problem with MPPT / batteries / connections / panels / fuses?

Any help / advice greatly appreciated.

Andrew Aikman asked
Andrew Aikman commented ·

3 Answers

MPPT sizing calculator - results Online vs Excel sheet

Hi all,

I'm quite new to PV and still have no clear idea of what I don't know yet.

So the answer to my question might be very obvious ;)

However I'd appreciate any insight you are willing to offer :)

I installed three 120W modules in series on the roof of my RV and the online calculator recommended the MPPT 100/20 for them.

So I went ahead and bought it, not understanding at that time that "20" is the max A to the battery (I belive at 14,4V? - so max output to the battery would be about 290W?).

The MPPT 100/20 charges a LiFePo4 battery, most of the bulk charge happens at 13 to 14V, so 260-280W..

The highest peak power I got out of the panels during the last couple of days was about 270W according to the Victron App. Battery SOC between 20% and 90%.

Conditions: Clear Sky, Germany, about 51° latitude and 7° longitude (I've calculated an airmass of about 1.2, but I could be wrong), module temp about 50-55°C, panels flat. Cables about 6m 4mm² (single length) from the modules to the controller and 1m 4mm² to the LiFePo4.

I'm wondering if the panels are just not delivering their rated power (within this conditions I'd expect to see above 300W) or if the MPPT 100/20 is a bit undersized. Or if the values in the app are simply not accurate ;)

Today I played with the Excel calculator "VE-MPPT-Calc-3_7" and after slightly altering it to show the calculated max current instead of limiting it to the max output current of the charger the diagrams look like this:



To me it looks as if the available power of the panels is limited by the MPPT 100/20 even at high temps.

So now (finally) my question: why is the online calculator recommending the MPPT 100/20?

Is it (for example) normal that panels are far from their rated power so it makes sense to undersize the controller in relation to the specs of the panels?

What am I missing?

Thanks for helping me understand :)

ulfertg asked
launacorp answered ·

3 Answers

Bluesolar MPPT 150/85 (VE.CAN) disables BlueSolar 150/60 (VE.Direct) charging with Color Control GX and ESS


I have the following setup:

Multiplus II 48/5000/70 (v466) with Tsense, Vsense connected, VE.Bus from Color Control.
Bluesolar MPPT 150/85 VE.CAN (v2.05) without Tsense and Vsense connected, CAN from Color Control.
Bluesolar MPPT 150/60 VE.Direct (v1.50) VE.Direct from Color Control.
BMV-702 (v3.10) with Vmid-point connected, USB to VE.Direct from Color Control.
Color Control GX (v2.57) running ESS, Optimised with battery life and with DVCC.

The most recent addition is the 150/85 CAN MPPT and after connecting it, the system appears to throttle down the other VE.Direct 150/60 MPPT almost completely. If I turn on large loads the VE.Direct 150/60 MPPT will start briefly but soon stop charging completely.

As per this screenshot for example with a 2.4 kW AC load:

The 150/85 as displayed is running at its full connected PV capacity of just over 1 kW. The 150/60 MPPT can deliver about 2.5 kW of PV capacity, yet remains idle. As can be seen by the BMV current draw at the top, the battery is actually being run down even though there is adequate PV power available to cover this load and charge the battery.

This persisted beyond the system going into Bulk with the 150/60 MPPT not providing any sort of significant charge.

When I unplugged the CAN connection to the 150/85 MPPT, the 150/60 MPPT woke up and started delivering full power while the 150/85 continued to provide it's ~1 kW (running in standalone). Reconnecting the CAN reverts to the previous state with the 150/60 dropping to idle. This leads me to believe that this is not a premature Absorbtion/Float issue as I watched the system get to a proper float state rapidly with the CAN disconnected and the 150/85 running.

I have tried toggling DVCC completely as as well as all of it's sub-options to no avail.

Both MPPTs also have the same absorption and float voltage settings and follow very similar cable runs. The only caveat is that they connect to the main battery cable just outside the Multiplus's DC input and not to the battery posts but I don't see that this should be an issue especially given the Multiplus's shared V/T sense connections.

Any advice on how to make the 2 MPPTs deliver full power (at least in bulk) would be appreciated unless this scheme is not actually supported. It seems that it should be. Given that it works with 1 MPPT in external control and a second without.

Kind regards

craig.tong asked
craig.tong edited ·

0 Answers

Charging voltage MultiPlus incorrect?

So I just setup my MultiPlus 12/800/35 with my VE.Bus Smart Dongle. I set de dipswitches to

1=off, 2=on, 3=off, 4=off, 5=off, 6=off

This should give me a charging voltage of 14.7 for my AGM battery, but when I check the app it says it has a voltage of 14.10 (sometimes drops to 14.07)

I did save the settings with switching 6 on and off.

What am I doing wrong?

Also, is there a way to change settings in the app or can you only see data?



e11enn asked
e11enn commented ·

0 Answers

BlueSolar 75/15 -- 12v PV in to 24v bank?

this has been asked before with no satisfactory and definitive answer:

can a 12V PV maintain a 24V bank?

what does one need to do in order to get this to work? connect the battery first, to establish V being 24V, and then attach the 12V PV to show the input current? is there any built-in buck boost in the BlueSolar 75/15?

I have read that a BlueSolar MPPT 75/15 will only start to charge when the PV output V is 0.5V more than the current battery bank V, then stop when it is under 0.1V, but does that mean that it absolutely will not work as 12/24V dependent/congruent system?

will it work from 24V PV to 12V bank? why not versa vica?


anderson.miles asked

0 Answers

1601 Posts
1539 Users

Topic Experts

3060 Points
1304 Points