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MPPT 75/15 wire terminal too small for 6mm²


I have a MPPT 75/15 and the specs say the terminal fits a 6mm² cable. I tried that cable size and it does not fit. Without a wire end ferrule it may go in but just and it is a hassle, some strands being bend and staying out (not good), with a crimped ferrule of the correct size (it tried two types) there is no way this fits.

I have some pre-crimped cable from the solar panel (this is a kit) and the ferrule there look like a size too small and it is a 10 gauge wire which is slightly smaller than 6mm² as well. And even that barely fits.

So what am I doing wrong? Do I need to switch to 4mm² cable? It is only the 1.2m length from MPPT to battery, but 6mm² cable is what I have....

Thanks, regards,


OR asked
npm108 edited ·

6 Answers

MPPT 75|10: Should I rather connect my devices to "Load" output or to a Bus-Bar together with Battery to "Battery" output?

Hi there, I am setting up my MPPT 75|10 SmartSolar charge controller for use together with a 12V Battery and two devices that work on 12V and require about 50W in total. I am furthermore using a 110W Solar Panel (max. Voltage: 18.27V, max. current: 6.03A). Let's get to my question.

I was advised to connect my devices and the battery to the charge controller by connecting two bus bars (for + and -) to the battery output of the controller and all devices and the battery onto these bus bars. I am however now realizing that there is a Load output where I could connect my devices to. So I am wondering if I should rather connect my devices directly to "Load"? What is the advantage and disadvantage of each method? Is it safer to connect directly to Load?

An insight to this would be very much apprechiated, thanks in advance!

PS: I also understand German ;)

smartsolar-usr asked
kevgermany commented ·

3 Answers

PV-Sizing für MPPT 150/45 + 6 x Trina Solar Vertex S 400Wp


es gibt bereits viele Threads zum Sizing der MPPTs aber keiner gibt mir "wirklich" eine belastbare Aussage.

Warum werden beim MPPT Calculator keine Warnungen ausgegeben, dass man die Nenn-PV-Leistung aufgrund der System-Voltage-Beschränkung gar nicht richtig ausfahren kann ? Oder verstehe ich da etwas falsch ?

Die TSM-400 DE09.08 haben folgende Daten

Power Tolerance-PMAX (W) 0/+5

Maximum Power Voltage-VMPP (V) 34.2

Maximum Power Current-IMPP (A) 11.70

Open Circuit Voltage-VOC (V) 41.2

Short Circuit Current-ISC (A) 12.28

Module Efficiency η m (%) 20.8


NOCT(Nominal Operating Cell Temperature) 43 °C (±2 K)

Temperature Coefficient of PMAX -0.34 %/K

Temperature Coefficient of VOC -0.25 %/K

Temperature Coefficient of ISC 0.04 %/K


Der MPPT Calculator spuckt mir für eine bspw. 3P2S Config unter STC eine Stringspannung von 102,6 @ STC aus. Wenn´s heiß / kalt ist beim Strom / bei der Spannung genug "Luft" für den Regler.

Allerdings - so verstehe ich es - muss ich nun die Systemspannung von 48 Volt (MP-II + Pylontech Akku Pack) x Strom der 3S2P Config nehmen ??? (48V x 23,4 A = 1.123,2 Watt) , welche der Laderegler "vom Dach holen" kann ? Also gehen 50 % der möglichen 2.4 kWp der 6 Stk. Trina´s ins Nirvana bzw. können nicht "verarbeitet" werden ?

Bitte klärt mich auf - scheine hier ein Brett vorm Kopf zu haben ... vielen Dank !

pv-willi87 asked
pv-willi87 commented ·

2 Answers

BlueSolar 150/60 mc4 terminal melted

Hi All,

As the title states, I've had an MC4 connector on my BlueSolar 150/60 MPPT melt. My question is are these replaceable? I'm kind of hoping I can screw it out and screw a new one in, or perhaps convert it to

I know most people are going to say "warranty warranty warranty", and while yes that would be good, the reality of my situation is that I live rural and bought this online so would have to post it and then wait on the seller and then wait on them posting it back. That could be 2 to 3 weeks, and to say it's not ideal to not have power (I'm off grid) for that long would be an understatement.

I don't believe the connector melted due to any fault of the unit, I'd say it was too much resistance in a bad connector. Charge at the time was well under the 30A recommended max of MC4 terminals.

So, any chance I am going to be able to replace the terminal myself?

wraithdragon asked
wraithdragon answered ·

2 Answers

MPPT RS 450/100 has mind of its own. Not using all available solar

I am having trouble getting the max charge current out of the RS 450/100. It’s set to 100A but it seems to be deciding the charge current on its own even though there is solar power not being harvested. I know this because when I flip the breaker on one of the solar strings the other one picks up the slack to produce more wattage.

I have 1200 AH of 48V lithium storage and its having this issue even with the battery at 40%.





solarmaniac asked
solarmaniac answered ·

2 Answers

MPPT 250/100 Capacity

Hi Guys,

Is there is limitation to the amount of watts one can transverse through a 250/100 MPPT?

I understand that the Max Volts is 250v but what about the watts?


denzel asked
Matthias Lange - DE answered ·

1 Answer

Solar Controllers going to float too early

Hi there. I have 3 x MPPTs on my boat connected to a SmartShunt which are all networked using VE Smart Network. I also use a Raspberry Pi running VenusOS which monitors the system. DVCC is off as I was told that SmartNetwork trumps DVCC.

I find at times (i.e. when I have been running the engine) that the charge controllers switch to Float mode too early. With my above setup, where are the controllers getting the information for when to switch from Abs to Float? Is there any way to force a reset for them to go through their cycle again? Any advice for improvement here?


lawrence-craig asked
lawrence-craig edited ·

2 Answers

SCC 100/50 low W-V

Hello, I will try to be precise. I have contacted my distributor of victron devices, and he has stopped selling, so I wonder if you could give me an indication here.

My system. Camper van, lifepo4 280ah 12v battery. 5 100W solar panels in parallel, mppt 100/50, orion 12/12, smartshunt, multiplus 12/1600/70 and CerboGx.

I would like to have the panels in series, but they can reach 116v and my charger is the 100/50. I can't fit another 100W plate to do series-parallel.

Since 9 days ago, my batteries have been discharging down to 20% (then I get the vrm warning). During the day the solar generates about 40-60W on average, before (even last summer, I had about 150-160wh).

Since a few days ago, the plates do not generate more than 40-60W, at some point of the day they can reach 150W (but only for a moment), then sometimes it goes down to 0W (lots of sun and no clouds).

I have checked all the connections and everything seems to be in order. I just need to check the mc4 connections of the solar panels, but it is quite inaccessible for maintenance and I would like to discard everything else first.

The battery is below 80% (I have done the tests with the SOC from 20% to 90%, same results.)

I have tried charging the battery from the alternator (Orion) it takes 18amps, and from the multiplus (takes 65amps) no problem. The battery is fine, and the cells are balanced.



A few days ago (as always, fine)




Just to add it, half of the time, the SCC is not giving any W as can be seen here (it never did it something like this, at least with the battery not full).


Thank you for your time, I hope I can fix it..

link-cat asked
link-cat answered ·

6 Answers

MPPT jeden Tag neuen Ladezyklus vermeiden


bei einer Inselanlage mit Bleibatterien, MPII und zwei MPPTs bleibt bei angeschlossenem Landstrom der Multi über nacht auf Float. Sobald die Sonne raus kommt, starten die MPPTs einen neuen normalen Zyklus mit Bulk, Absorption und Float.

Kann man dies zur Schonung der Batterien vermeiden?


Martin asked
Matthias Lange - DE answered ·

1 Answer

Battery protect 220A, voltage drop

Have a BP 220 unit. IN-pin connetcted to plus on Li bat with fuse inbetween. Also connected to IN-pin there is a multiplus and a smart solar connected.

When I add load through the BP I got voltage drop when turning on smal consumers from 13.4 to 12.9v (lamps). When using bowthruster och windlash the system shuts down totaly.

If I remvoe the BP everything works fine, what is the problem?

I have bought a second BP and I got the same behaviour with that one.

Best regards


kim-hilding asked
freighttrain answered ·

3 Answers

MPPT 450/100 display as "NOT CONNECTED"

Hi everyone. New Victron user here :)

I have :

  • an MPPT 450/100 connected using VE.Can to a Cerbo GX (terminator connector used on each one)
  • a Multiplus-II 48/8000/110-100 connected using VE.Bus to the Cerbo GX
  • Pylontech batteries connected to Cerbo-GX using the good Victron cable to the Cerbo-GX
  • DVCC is on ( charge informations are provided by the Pylontech BMS)

I have a strange behavior with the MPPT not showing as PV Charger on the VRM online and marked as "NOT CONNECTED" on Device List.

More strange, when I connect to the MPPT solar, or when I reboot it, it appears in both device list and VRM, but only for approximatively 30 seconds and then it desappers again.

I monitored the device list and sometimes, the MPPT is showing up by his own, but only for a few seconds.

Note that the device itself is working well.

I have tried using another cable, but the behavior's still the same.

Has someone experienced the same problem ?

Maybe it is "off" at night with no PV production ?

Thanks for your help or advice :)

jncanches asked

0 Answers

VE Smart voltages not matching

I figured out I could use VE smart to tell my MPPT what the true voltage at the battery was.

Except it’s not so smart. The mppt has gone into float at 3.6V but the battery is still at 3.45 as reported by the smart bus.

Isn’t this exactly what smart networking is supposed to correct? The mppt should be running at higher voltage knowing the battery isn’t full.

gsking asked

0 Answers

Mppt 75/15 better at 12v than 24v?

I hooked up my controller to my panels in series thinking it would work better. But each panel produces 115w at 17V… in series I don’t get above 170w but the voltage jumps to 40v

Is the voltage converter unable to trade that excess voltage for current?

In parallel I would exceed 15a, but it states that is an output limit on each output (load and battery). Can I put in up to 20a from the two panels in parallel?

Edit: I found most of the issue. I can only get 15a total output, half of which goes to the refrigerator. The other half is limited by peak voltage. The rest goes to waste. So 350w of panels will be overkill.

Now I just need to learn how to force it to go into bulk charging instead of float.


gsking asked
gsking edited ·

3 Answers

Smartsolar MPPT 150/85 VE.Can rev2

Guten Abend,

über mein Cerbo GX wird der tägliche Verlauf nur für heute und gestern angezeigt. In der App direkt mit dem MPPT verbunden sind alle Tage seit Inbetriebnahme vorhanden. Firmware v3.10


dirkvongracefacrory asked
dirkvongracefacrory commented ·

0 Answers

Dual MPPT connected to Cerbo GX via VE.Can results in almost zero output from second MPPT

My system consists of a Multiplus II, two MPPT 250/100, SmartShunt 500A and a Cerbo GX. The MPII is connected to Cerbo via VE.Bus. The SmartShunt is connected to Cerbo via VE.Direct. The two MPPT are daisy chained to the Cerbo via VE.Can with terminators at each end.

My problem is that when the two MPPT are connected to the Cerbo, only one of them produces normal output and the other one is near-zero output. As soon as I disconnect the VE.Can, both MPPT produce normally as confirmed via VictronConnect. Plug VE.Can back in and it goes back to near-zero. This happens whether VE.Smart networking is configured or removed.

I have tried every possible combination of wiring and configuration and the end result is always the same. Is this a bug in the software or am I missing some fundamental configuration problem? If I switch to using VE.Direct connections to the Cerbo will I still have the same problem?

akbast asked
trevor-bird answered ·

1 Answer

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