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Low watts from solar panels.

I have 3 LG 420 watt panels connected in parallel through a combiner box connected to an Smartsolar MPPT 150/100. The first few day after I turned my system on the Solar watt gauge on the app showed around 890 to 940 watts it was a partly cloudy day so I expected this. However today it's clear and sunny but I only showing about 80 watts solar on the app. Does the charge controller limit output from the panels once the batteries get to 100% SOC? I assumed the gauge on the app would show how many watts the panels were putting out regardless of battery SOC.

kkesp asked
Kevin Windrem answered ·

1 Answer

Suggestions for Newpowa 400W System Emergency/Backup Power

My Wife and I recently purchased about 2/3 of the equipment we need for solar power backup, for our fridge/freezer/portable ceramic or radiant heater, in the event of a grid power outage, and would love if there was a realistic and budget-friendly way to have the backup power come into effect automatically when grid power shuts off (if this is possible). So far, we have (4) 100W Newpowa Panels and the 40A Newpowa MPPT Charge Controller, as well as a Newpowa 12V AGM 100ah battery.

We would like advice on where to go from here to try and achieve our goal above.
1) Best equipment to act as a generator - A power station? A pure sine wave inverter? Other?
2) Do we need any additional monitoring device or devices (ie; low voltage auto shutoff) for the system?
3) We planned to connect the solar panels in parallel - is that the best choice?

Sorry if I haven't provided enough information here. I am a newbie, so am not sure what you need in order to offer some advice.

Thanks in advance!

arima asked

0 Answers

Different panels on 150/100 Mppt sets?

Hi fellow solarians,

I've got a Easysolar with built in 150/100 mppt.
The mppt has 3 sets of MC4 connectors.

I had the setup running the last 3 years on 4 LG NEON 320W panels (LG320N1K-V5).
Wired in P/S combo.
Worked excellent. But now i'm rebuilding the house and need more power.

So i'd like to add 8 more panels on the other two available sets and get almost 4 KWH on a great day!

Problem is the LG's are very hard to get in Spain, plus it's an older model and they only sell the 330 or 340 types.

My question is can i put in 8 * 340W panels on the other sets in the same P/S combi setup or do i need panels with the exact same specs as my original 4 LG's?

If other brands and/or other W's are also possible it's a cheaper and better option (I can wire in series and get more V.)

Any tips or advice is greatly appreciated.


marcel-solar-spain asked
Mike Dorsett answered ·

3 Answers

How to connect solar panels and eventually to my MPPT?


I have 6 LG Neon 2 360W Panels and I want to connect 2 strings of 3 panels. I have purchased 8metres of 4mm2 Twin Core Solar Cable and 10metres of 6mm2 Twin Solar Cable. I have just spoken to a friend and he said why did you get twin core, you should have got single. Can anyone tell me the difference and how you would connect my system with twin core solar cables?

Any Help will be much Appreciated


jsheehan asked
JohnC answered ·

1 Answer

Damage to new solar panels.

I'm new to solar and not sure what imperfections/damage is unacceptable.

I have received a new panel from a UK supplier but unfortunately it looks like one of the cells is cracked, should i be concerned?


I would send it back without asking here but it was on a good discount and the service I have received from them has been poor and could end up waiting/chasing them. I appreciate there are current supply issues but 3 out of 3 orders over the last few months have had items out of stock even though listed as in stock.

flippynips asked
chrish answered ·

2 Answers

Running a MPPT 150/100 at 160 Volt bad?

Hi, i have a Victron 150/100 with 3x LG Neon R 370 watt solar panels rated for 370 watts at 37 volts and 10,01 amps

thing is, that should be 1110 Watts of solar but i often get 1200 and even 1300 watts for more than half an hour thats 120 Volts at 10 Amps

im thinking of putting a 4th panel on the roof

That would be 1480 watts with 148 volts at 10,01 amps

Theoretical ok as datasheet states

but im expecting it would also over-deliver at 160 Volts- 10 amps

thast 10 volts over rated voltage of the expensive Victron Unit.

Will this cause problems?

finalshare asked
kevgermany commented ·

2 Answers

Will this mixed solar panel configuration work

I run a facebook group dedicated to teaching solar. Typically i advice against mixing solar panels because most of the time the efficiency losses are to high. So i will advice multiple charge controllers.

However this diagram was posted on my Facebook group. (This is NOT my design).
If you follow the math to it’s conclusion I get 98.44% efficiency.
However if you look closely at the diagram you will see he has mixed configuration creating sort of a 2P/2S/2P configuration.

My question is will this work. He has basically done one parallel string (2P) and then a series/parallel string (2S/2P). Then taken all that and put those in parallel as well.

Will this work? Theoretically the math comes out but can the Smartsolar 150/70 understand what is happening here and look at it as just a 2P config or will it freak out?


Thanks for your help.
Guy Stewart, would you have any thoughts on this?

@Guy Stewart (Victron Community Manager)


off-gridin-it asked
off-gridin-it edited ·

1 Answer

Solar parallel / serial on a narrow boat roof


I currently have 3 solar panels in series on the roof of my narrow boat, and have ordered 3 more. As I have a 150/70 MPPT, I need to setup the panels in parallel / serial.

To minimize the impact of shading, I was thinking to get the best performance over the two sets of panels, I should stagger them.

The first series would be panels 1, 3 and 5, and the second series would be 2, 4 and 6.

Am I right that this should provide the best output, or am I over thinking things?

Many thanks,


simon-forester asked
Mike Dorsett answered ·

1 Answer

Solarpanel kaputt? Mppt 75/15 Laderegler


Ich habe den Laderegler Mppt 75/15 mit Bluetooth neu eingebaut (mit Konkurrenzprodukten habe ich aber das gleiche Problem).
Ich habe die Leerlaufspannung gemessen ca. 21-22 Volt die Kurzschlussstromstärke beträgt ca. 3,5-5 Amp bei einem 120 Wp Panel.

wenn ich das Panel an den Regler anschließe sackt die Spannung auf die Batteriespannung runter obwohl genug Sonne auf das Panel scheint.

Der Regler gibt dann keine Ladung weiter da er sagt die Panelspannung ist zu niedrig.

Heute morgen um 7:00 dann kurz die App angemacht und siehe da die Leerlaufspannung pendelte zwischen 15 und 20V und er hat in 10 Wh geladen (trotz so gut wie keiner Sonne; bewölkt).

Jetzt wo die Sonne wieder draufscheint sackt die angezeigte Panelspannung in der App wieder auf 12,3V runter und es wird nicht mehr geladen.

Versteht das hier vielleicht jemand?

Grüße Tom

ps. Vor der Winterpause hat das Panel noch funktioniert.

tinab asked
mf8282 answered ·

3 Answers

Is it possible to use the EasySolar II to charge an EV ?

Hello, Is it possible to use the EasySolar II to charge an EV ?

What I mean is just used it 'islanded' to change a electric vehicle directly.

Solar panels > EasySolar II > EV

myozone asked
Matthias Lange - DE commented ·

2 Answers

Fusing 2 different paralleled solar panels

I am planning to renovate an old rv camper, and want to install solar panels. Due to size limitations, I need to mix different BlueSolar mono panels:
one of 360Wp (max power voltage: 38.4V, max power current: 9.38A, open-circuit voltage: 47.4V, short circuit current: 10.24A), and
one of 215Wp (max power voltage: 37.4V, max power current: 5.75A, open-circuit voltage: 45.82V, short circuit current: 6.30A).

For the fusing, one website tells me to look at the maximum series fuse rating. However, I am unable to find those ratings for these panels. Would it be correct to use a 10A fuse between the Y connector and the 215Wp panel, a 15A fuse between the Y connector and the 360Wp panel, and a 25A fuse between the MPPT and the Y connector? Are all of these fuses necessary?

Additionally, what would be the advantage of circuit breakers/switches? And are they useful in any of my fuse locations?


Any advice would be much appreciated:)
(I am fairly new to electricity and solar panels)

jadmeest asked
Alexandra edited ·

1 Answer

How to choose a solar panel

Hi folks,

I'm going to buy a 100w solar panel for the monitors around my house so that I don't have to worry about the cables and holes stuff. Anyway, I've watched some on youtube and dug into these brands: (Renogy100 W 12 V Monocrystalline, Goal Zero BOULDER 100 SOLAR PANEL, NEWPOWA 100W 12V), which one would you guys recommend the most? Any replys&suggestions would be welcomed.

crazyaboutrvlife asked
basil katakuzinos commented ·

1 Answer

How to choose a solar panel for my monitors

Hi folks,
I'm going to buy a 100w solar panel for the monitors(Full HD 920 x 1080) around my house so that I don't have to worry about the cables and holes stuff. Anyway, I've watched some on youtube and dug into these brands: (Renogy100 W 12 V Monocrystalline, Goal Zero BOULDER 100 SOLAR PANEL, NEWPOWA 100W 12V), which one would you guys recommend the most? Any replys&suggestions would be welcomed.

crazyaboutrvlife asked
basil katakuzinos answered ·

2 Answers

Q- Cells 475 Watt Solar Panels and MPPT 150-70


Looking at using 2 - Q Cells 475-watt solar modules and one of the Victron MPPT cc's to charge 2 - 200 ah batteries.

My application is for a vehicle and off-grid with the ability to use a second alternator to also charge the batteries. Will also use the smart shunt as well.

Will this cc do the job or should I select a different model?

Will it be possible to run them into the cc at a higher voltage and then drop down to 12V dc for the vehicle?

Am I thinking about this correctly or should I pick a lower wattage/voltage solar panel?

Thank you!



electrichi01 asked
electrichi01 answered ·

2 Answers

MPPT voltage during Dark hours.


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How is it possible to have voltages from the panels, it's pitch blank outside, not even the moon is on the sky.

sebastian-w asked
rickp answered ·

1 Answer

Hola, soy Noah ¿Qué paneles sirven para mi casa de playa?

Hola, me gustaría conocer qué paneles sirvan para casa de playa en el sur de España.

Quiero ahorrar en electricidad lo antes posible.


noahdejong asked
rmaddy commented ·

0 Answers

Bad performance af Bluesolar MPPT 75/10 with 40W of panels

I am struggling to find the cause of very bad performance of my sailboat 40W solar panel installation.

The controller is Bluesolar MPPT 75/10. There are 2 horizontal panels of 20W each, connected in parallel. The panels are Sunbeam Tough Flush T20F. According to data they are supposed to have Vmp=20.88V, Imp=0.99A, Voc=24.48V and Isc=1.19A each.

My gel battery is not full and needs charge. The last weeks there has been plenty of sun. I am in south of Sweden. However the max power seems to be only mediocre 4W and a typical daily yield is only 30-50 Wh. The panel current sum normally is 0.3A in full sun when the panels are not shaded.

The cable is 2.5 mm2 from the panels. I have checked all connections. I even tested another temporary cable just to be sure.

According to nearby weather stations solar radiation intensity is typically 960 W/m2 at this time of the year, which is not that far away from the test conditions 1000 W/m2.

According to the Victron calculator the panels should produce almost 150 Wh/day or a max charge current of around 3A. But my poor 30 Wh/day or max current 0.3A is simply so much lower that I am now frustrated. I was hoping for at least 100 Wh/d or perhaps even more. A max power of 25W or current of 2A was also in my expectations from this 40W installation.

With a Fluke 179 multimeter I have measured the sum from the two parallelled horizontal panels as Voc=21.9V and Isc=0.95A when in max sun at 13:00. That is much lower than the panel data, isn't it? As there are two panels Isc should be 2*1.19A=2.4A at perfect conditions.

My tests also reveal that one of the panels seems weak, as it only gives half the current than the other does. And its voltage seems lower than the other.

The solar panel producer Sunbeam says that the Victron controller is not good enough and wants me to buy theirs instead. They say that their controller starts at a much lower voltage difference and consumes much less power, They say it is better than the Victron, in what ways I don't know.

I have read various posts here on the subject, but it seems as everyone is getting much more out of their panels than I do.

Should I claim warranty on one or both of the panels?
Or am I simply expecting too much?
Or could there be a problem with the Victron Bluesolar MPPT 75/10 controller itself?

johwin61 asked
johwin61 commented ·

4 Answers

Upgrading my system without any new parts by rewiring?

I have 4 100w panels (WindyNation) wired in parallel to supply 12v to Victron Smartsolar 110/30 controller. If I rewire them to either series/parallel (24v) or straight series (48v) will I be able to still charge my 12v battery bank without any additional equipment? This will lower my voltage loss on my pv cable (12awg) as well, yes? Will it make a noticeable difference in being able to recharge my system w/ marginal (cloudy) skies?

dixonge asked
Kevin Windrem commented ·

2 Answers

MultiPlus Compact 12/2000 does not charge

Hi guys,

When AC is connected, after 10-15 seconds Multiplus Compact tries to switch on charger (as usual) and then immediately relay switches it off (almost simultaneous relay clacks). Looks like protection.

1) Wiring is correct (grounding, live/neutral)

2) AC is pure and fine (was working 3 days with it)

3) Boat installation

4) Checked with disconnected ac output - same behavior

5) Issue appeared after some rewiring work on the input side (connecting everything back as before did not help either).

6) Battery is 12.8V. No other chargers connected.

7) Invertor works fine (means DC and AC output lines are correct), AC output is working fine.

Question - what is going on with MultiPlus and how it can be healed? Does this mean unit is broken now?

Kind regards, Serhiy

serhiy-trylis asked
klim8skeptic commented ·

2 Answers

How many Trina Solar DE15M(II)'s can I connect in series with MPPT 150/35?

I already have a new MPPT 150/35 Charge Controller and six Trina Solar (Tallmax) DE15M(II) 395-420W panels. The panel Voc is listed as a range (not a single value): 48.7 to 49.7v at 395 to 420W (respectively) at Standard Test Conditions and 45.9 to 46.7v , same power output range, at Nominal Module Operating Temperature. I live at 38.5375 deg. N. lattitude (maybe 60 miles north of San Francisco, CA as the crow flies). The Victron Energy MPPT 150/35 lists Max PV Voc of 145v start-up and operating conditions, 150v absolute max. coldest conditions. It seems like I can therefore just "squeek in" connecting 3 of the DE15M(II)'s in series, and have two of those 3-element strings in parallel going into the charge controller. The battery bank is 48v (eight 12v batteries, 4 in series, two sets of those in parallel). The panel short circuit current is 10.37 to 10.76 A at STC so that seems fine either way (3 x 2 or 2 x 3). Is this correct? Would 3 strings of 2 panels in series be better, safer, ...?


rcblasdell asked
rcblasdell commented ·

1 Answer

Mono 4a series panel vs Pany HIT

Panasonic have stopped their HIT panels, shame as I was going to fit a n250, just the right size for my van but then I found the Victron 4a series panels, the 175 and the 215.

the HIT were apparently famed for their ability in low light and cloud and I wanted to ask if anyone knew of comparisons with the Victron 4a series in this respect? Also I can’t find any figures relating to the efficiency of the 4a.

Can anyone advise please?

pusscat asked
wkirby answered ·

1 Answer

Choix du Parafoudre DC devant MPPT

Impossible de trouver dans les doc VICTRON quelle tension max peut supporter en particulier un MPPT 150/35 et un SmartSolar 450/200 (et tous les autres bien sûr). C'est une info nécessaire pour choisir un parafoudre de type 2 qui "écrête" à une tension inférieure à cette tension recherchée sur le MPPT.

lolei31 asked
lolei31 answered ·

3 Answers

Adding in occasional use panels

I have a 100w 12v panel on the roof of my camper, connected via a Victron SmartSolar MPPT 100V 20amp controller. I want to add an external portable 100w 12v panel that I can move around to face the sun better. I think I can wire both panels in parallel into the charge controller, and disconnect (via power poles or the like) the portable one when not in use.

Is there any danger in this kind of a configuration? Or am I looking at it incorrectly?

Thanks in advance!

eric-linxweiler asked
eric-linxweiler answered ·

2 Answers

VictronConnect App zeigt seit Installation 0W


ich habe letzte Woche meine Solaranlage angeschlossen. Ich habe einen MPPT 75/15 Laderegler und eine 12V Lithium-Batterie. In der App wird mir dauerhaft Spannung (V) angezeigt, jedoch kein Watt oder Ah. Woran kann das liegen, dass das Paneel nichts einspeist und somit anfängt die Batterie zu laden?
kann das an der Reihenfolge der Montage liegen? Ich hatte auch bereits gelesen, dass die PV Spannung 5V höher sein muss, damit der Laderegler anfängt zu laden.

janek-buss asked
jajaja answered ·

4 Answers

Solar Blankets and Charging Input for battery.

So recently I had an issue with my 4A charger for my deep cycle battery and found out that I’ve been using an underpowered charger for my 100ah AGM.
Ive purchased an ip65 15A from now on. As I’ve been informed that I should be charging my battery at 10% of the capacity of the battery. This raises another question for me.
Can someone tell me why it’s generally perceived as acceptable to use 200-250w solar panels for charging AGM Batteries, even though most of those panels would struggle to output 10A let alone 10% of a larger battery?

benny23 asked
Mike Dorsett answered ·

1 Answer

Cable fittings dont fit SPM040551200

Hi I just bought a SPM040551200 with Victron Solarcable L=5m/6sqmm MC4-M/F conn. (PV-ST01). The water tight cable box has fittings that are too small to fit that cable (with contacts removed.) What type of connection and cable am I supposed to use? The dealer I used is a certified victron dealer, so I thought they would tell me if something was wrong, when I mailed them before I placed my order.


mcdee asked

0 Answers

Charger for 2 x AGM 100Ah boat batteries?

I have a camping boat with 2 x 100Ah AGM batteries and a switch panel for 1, 2 or 1&2. Starter battery (1) and battery (2) for the fridge, Ipads etc. I want to be able to charge fairly quick when there is access to shore power, use solar when in nature and to keep batteries full when at harbour (no power there).

What charger is best for my setup? Thinking of these...

Blue Smart IP67 12V 17A

Blue Smart Ip22 30a/3

Blue Smart Ip65 25a

For solar this is my thinking. Connect this to both battery 1&2?

Solar panel 100W with regulator Smartsolar Mppt 75/15

In the future I’m considering changing battery (2) for a lithium if needed.

Im new here so any recommendations is greatly appreciated.

marcuslundh asked
shreeyash answered ·

1 Answer

How to charge one 12V and one 24V batteries with one solar panel?

Hi, on my boat I have a 12V LFP and a 24V LFP batteries.

I wonder if it is possible to keep them charged with one single 200W (29V) solar panel, and what equipment would be needed.


mporta71 asked
mporta71 commented ·

1 Answer

Can I use a common negative bus in a 4 MPPT & 4 PV installation?

Hi All. I'm going to install my set, having 4 100/30 each one connected only to a single 450W PV, in a 12v installation. This is already discussed in a previous discussion, and this approach is for the shadows managing and also for the cost and redundancy, beeing better 4 than 1 regulator.

I wonder if, in order to save cabling from 4 to 1, and routing and path (it is thin and strechy), I can connect all the PV negatives to a single 1 cable negative in the PV side, with a section 4 times AWG previuosly selected, and way this to reach all the regulators site, where I will spread again each negative to every regulator PV- input

Positive cables will run independiently , 4 .

Can be possible?

Is there any cons, apart from that if I added new panels I must to run new negatives?


combatdiver asked

0 Answers


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