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Solar / pump project

Hi All,

My apologies for the basic level of these questions!

I have a project in mind and I really need help because I don't want to make mistakes.

The project is to using solar panels to power water pumps to provide water (from a stream) to my crops.

So, I planned to buy:

- 6 solar panels of 300-350w each

- 6 water pumps of 240w (CC 24v / 10a or 12v / 20a) each

My wishes :

- Ideally, each panel feeds and controls its own water pump.

- No need for storage / battery

- Remote control management

- MPPT system to optimize performance

- But most importantly: I want to have a regenerative system in case the water pumps are not needed or when the solar panel delivers more power than necessary.

What are the equipment needed for this installation?

Thank you in advance for any help!


incree asked
tmo answered ·

3 Answers

Plug in extra 100w panel directly into mppt charge controller


I have 2x100w flexible panels on my roof. The max wattage I get through these is roughly 50 watts (my advice, never buy flexible panels, too much efficiency loss in heat). Amperage is thus around 4. I would like to add another 100 watt panel (rigid). Can I run the wires of the new panel directly to my mppt 75/15 controller and join them there with the existing ines? Or do I need to join them before?

I think the 75/15 could handle 3 x 100 watt panels (12v) if two of the panels mostly operate at 25% efficiency, right?

Thanks a lot in advance.

totomundo asked

0 Answers

parallel MPPT controllers with different solar input voltage

I have 2 MPPT 75/15 controllers, each connected to two parallel 12V(18V)/100W panels. Battery is 12V.I would like to increase the system with two more 100W panels. But I am thinking of using 36V panels instead of 12V, as the cable losses would be lower and connect these panels to one additional controller. The controllers are interconnected by VE smart networking. Will there be any problems with the synchronised charging in this setup?

martinr asked
alan answered ·

1 Answer

Solar panels and BVM 712

My RV has two 12 volt lead acid batteries (in parralel) connected to a BVM 712. I am considering using stand alone solar panels to charge the batteries in situations where generators are not allowed. The solar panels I am cosidering are 4 - 25 watt panels in series connected to a controller. The contoller has alligator style clip that are meant to go directly on the battery terminals. I know that if I do that the BVM will not see any incoming voltage and therefore be inacurate. Can I connect the Positive clamp to the battery and the negative clamp to the load side of the shunt, and then the BVM would "see" the incoming volts? Thanks for any help or suggestions.

donaldn01 asked
stefanie commented ·

2 Answers

Solar panels 12v vs 24v for a 12v system using victron mppt 250/100.

Hello, I am converting my sprinter into a camper van, I have 4x 12v 100ah battleborn batteries in parallel for a 12v system, and victron 250/100 MPPT. I would like to use 3x 320W Monocrystalline Solar Panel ( like Renogy RNG-320D-H )

When read spec sheet it says these are Renogy 320 Watt 24 Volt panels, does it mean that it can work only with 24v batteries? I thought the MPPT should handle the voltages from the panels. If I understand it correctly even if I had a "12v" panel I would need 2 in series to drive power to the batteries. Why is Renogy referring to it as 24v panel?


Manoj Iyer

manjo asked
michelg edited ·

5 Answers

Prioritize PV Solar over Grid

Hi -

I have an RV and am looking to consume Solar first then the grid or have the Solar off set the grid.

I’ve done research but can’t seem to find clear guidance on how / what needs to be done for my system in order to prioritize Solar over the Grid and would appreciate any help.

My system:

Multi - 3000kva/120v


SmartSolar MPPT 100/50

6 - 100w Panels

440A AGM Batteries - 12v


Overall, I want to offset the grid consumption with any available Solar.


tabney0315 asked
Paul Carmichael edited ·

8 Answers

Do I need a solar regulator with an Orion TR?

I have connected everything according to the instructions. When not connected to the car, the solar is coming in via a voltage relay switch. In the app it's showing 19 volts coming from the solar panel and I'm get the error: 'charging disabled' and 'remote input not activated'.

Am I doing something wrong? Do I need a regulator to bring that voltage from the solar panel down? What am I supposed to do with the jumper?

Help greatly appreciated.



chrisg asked

0 Answers

Change solar panels

Hi, I have 2 x 180 W solar panels Victron SPM011802400 on my boat. They are now 8 years old and working fine. Due to increased use of electricity want to upgrade to 2 x 215 W Victron SPM042152400. that should give ~ 25% increase in output, I hope. I do not want to upgrade to larger panels due to space limitations. I have one charge controller for each panel, so in total two Victron 75/15.

Question: can i just simply swap panels, same with same, or my installation will have to be amended ?

thanks in advance for your response.

Franc asked
Paul B answered ·

1 Answer

Van solar electric scheme 24v and 12v

Dear forum:

I have been exploring the web and seeing a lot of electrical diagrams for a Solar installation in a camper van, but non with the idea I had in mind, so I'm sharing my scheme.

My idea is to have 2 x 180W Solar panels serial conected to have 24v output connected to a MPPT solar controler to charge two 12v batteries (115Ah each, serial conected 24v total). I would like to be able to charge those batteries also with the van alternator, and someone in the forum suggested me to try the Orion DC to DC high power 12v to 24v 450W.

From there, control de batteries level witht he BMV 712 Smart, and some other components (see int the scheme) to have a 12v power line, an inverter to have 220v, etc.

I would appreciate a lot if anybody could comment on this, give me his/her opinion, It is my first electrical scheme, I know there might be some basic error (I'm not sure how to wire the Orion 12v to 24v to the alternator/starter battery and bank batteries), things to be corrected or improved.

All fuses and wire diameters still in process




pepvan asked
pepvan answered ·

3 Answers

What happened to the live PV panel test?

The Which solar panel test seems to have concluded only 4 weeks after being announced.

What exactly was the conclusion?

klim8skeptic asked
klim8skeptic commented ·

2 Answers

Victron MPPT Calculator - how does it choose what MPPT to suggest?

Hi guys.

Could someone help me understand the rationale how the MPPT Calculator comes up with the suggestion in the attached screenshot for this array of 4x150W panels and why is it not suggesting the 100/50 (which I have already purchased)? The Max. V in min. temp. stays under 100 AND the MPPT need to limit the output current to 45A, so why not suggest the MPPT 100/50?

Also, are there 'sweet spots' in these MPPT's regarding the V's and A's coming in from the solar and what would these be for the SmartSolar 100/50?

Is there something here that I'm missing / not understanding? Could I still use the MPPT 100/50?

For what it's worth my other van conversion components include MultiPlus 12V 2000/80, Orion-Tr 12-12/30, SmartShunt and Cerbo GX. I'll be storing the energy in two 150Ah LiFePO4 batteries, with max. charge current of 100A each.



mako74 asked
rickp edited ·

1 Answer

Japanese RV Build— Stuck on Bulk / Configuration Review

Hey Folks,

Appreciate you stopping by. I’m new to this area, but I’ve done a bit of research to solution for various other issues.. That said, i now am a bit stumped and would appreciate some help.

Background on my set up:

  • 180w NewPowa solar panel x2 (Run in parallel & Fully tested before and after install)
  • Victron MPPT Controler 100| 30
  • Battle Born LiFePO4 (lithium) 100Ah 12v battery x3 (total 300Ah) run in parallel
  • Victron BMV 712 Smart Monitor

Configuration for Victron systems:

Pictured below are my key setting configurations for my set up. I used the manual as well as some other threads to determine my settings.

Settings for the 100| 30 Controler :


Settings for the 712 Smart Monitor:



  1. Based on my Whole electric system, does my configuration above seem to be accurate or are there pieces that I should re-evaluate?
  2. Today and yesterday (during the day) my system has been stuck in ”Bulk”, which from what I read, means that the batteries are low and the system will bring in large amounts of power to charge them. The issue is that the batteries are very close to being fully charged. (below is some data from the app showing that I’m stuck on float) . I think its important to point out that I have been able to put a load on this and see my numbers and battery voltage adjust but I continue to stay in “bulk” . What could be causing this?



  3. Possibly related to #2, today during a sunny day, my solar panels were barely bringing in any watts 30-50w range, while in bulk model. My battery on the monitor was at 95% or 13.4v but it didnt seem like it was going up at all. Any reason why this was happening?

Any help is greatly appreciate. Happy to provide more details around certain aspects.

Here are some additional data grabs...

Below is a picture from the monitor today while having a slight load on it (fan, heater, lights):


Here’s a picture of the van when I bought it.. It’s changed a lottttt since then.


coleinavan asked
coleinavan commented ·

3 Answers

solar configuration

Hi, we are thinking of putting solar on our boat. The system we require is not as complicated. We Have battery storage capacity of AGM 1000Ah and use approx 1/3 or 30% of that storage over a 12 hour period. We run the genset for 3 hours in the morning and then again in the evening. We have room for 4 maybe 6 x 360Watt panels. 4x360W 1400W My thoughts are and your recommendations are essential. We need to generate approx 90Ah per hour for 8 hours to recharge our batteries from the night consumption while still generating our hourly usage. I think that is 1080 watts per hour? Now do we use mono Perc p-type panels in series which will give us greater voltage therefore better in low light eg morning and evening? Or do we have them in parallel that gives us greater current? Also do we put a small regulator on each panel so the panels are independent if a shadow from the radar tower falls across one. What percentage of the panels in shadow will effect the performance of the panels connected to each other? Or do we put say two MPPT controllers in, one for the panels that may get a shadow and one for the other panels? I look forward to discussion.

Cliff asked
Paul B commented ·

2 Answers

Excel MPPT sizing vs Online MPPT - Need help - Can this work?

Hi All.

Need help determining if this can work or not. Excel says no, Online says yes. May well be operator error, not sure.

I have a EasySolar 3000 (Specs - for off grid work.
I'm have the panels from my house (which I have since upgraded) 10 x Sharp NUSOE3E panels 30v x 180A - approx 8-10yo.(Specs -

The EasySolar has a 150/70 MC4 inside, so was going to do 2 strings of 5 panels.

Challenge is excel says no, can only do 2 x 4 panels, online says yes I can.

I don't really want to overload and kill the thing, and it's remote so don't really want to start a bushfire either.....

Can anyone shine some light? I'd like to use all 10 panels for the best capacity if possible, but wondering if the panel specs versus MPPT specs may mean that's not possible.


sbe asked
klim8skeptic answered ·

1 Answer

Help chosing the right MEGA Fuses for this set up

Hi everyone. I am having some doubts about which fuses should I chose for this set up and I would like to know opinions.

The set up is:

-4x Pylontech 2,4kWh US2000

-Multiplus II 48V 5000VA

-MPPT 250V100A

-Lynx Distributor for the mega-fuses

-3S3P 490Wp (Voc 153,9V Isc 36,42A)

I have been checking some videos and I see 3 mega fuses that I would need:

-For the battery bank: 125A? Checking these q&a I determined this is the right one needed.

-For the MPPT: xxA?

-For the MPII: 200A? According to the Manual, page 11 4.2, says 200A recommended DC fuse.

I would appreciate any help on this. Thanks a lot

tpwchr asked
spudgun answered ·

3 Answers

Can I use 24 volt solar panels to charge 12 volt batteries through MPPT Controller

I’m trying to spec a system using all Victron kit and looking at the 100/30 MPPT charge controller. Does that controller accept 24 volts from solar panels and charge 12 volt batteries?


stevecounsell asked
Trina commented ·

2 Answers

Solar panel config on a boat

I know versions of this type question have be asked before , so bear with me

The boat has 2x SPM100-12/3a panels , no MPPT, I was going to upgrade to 2x SPM0417512 , 170W , series 4a panels

However I have space for all 4 panels , I was thinking of wiring each 100W in series with a 170 W , and paralleling it to the other 100+170W set of panels , using a single 100/50 Smart solar controller

is this a feasible solution , in general I dont have a shading issue , typically at anchor with the sails down as the panels are mounted above the Bimini .clearly I could put each series string on a separate mppt controller, but costs mount

thanks in advance


goboatingnow asked
JohnC answered ·

1 Answer

17v vs 18v Vmax panel with 100/20 MPPT

Hi all,

I am building solar system for a small Airstream trailer with very limited roof space, my goal is to get > 200w panels. Due to roof top space limitation, My panel selection is limited to the 2 options below.

1. Renogy 100w + 50w + 50w (Voc: 21.6, Vmax: 17.9) total 200w

2. Newpowa 75w x 3 (Voc: 20.3, Vmax: 17.0) total 225w

I am leaning towards #2, as it offers more watts and having the same panels are always a plus.

But since I need to install them in parallel due to roof top A/C unit shading, I am concerned that the ~1v Vmax drop in Newpowa might not work well with my Victron SmartSolar 100/20 SCC and LiFePo4 battery bank (13.4v fully charged)

According to SCC manual the

Voc needs to be 13.4+5 = 18.4v for SCC kickoff charging

Vmax needs to be 13.4+1 = 14.4v for SCC to staying in charging

This is very close to the spec of Newpowa panels (20.3v, 17v) and I am wondering if it's a bad idea to use these panels - panels won't be able to supply high enough voltage for SCC on a cloudy day? The Renogy panels would have a more comfortable margin and should be used instead?

Thanks in advance!

hovr asked
hovr commented ·

1 Answer

Solar panel confusion

Hello, I am looking for advice regarding updating my current solar panel setup on my leisure vehicle.

Currently I have a single 80w panel and a Victron 75/10 controller. With weight on the roof being the constraint, I think I have three options:

  1. Add another 80w panel and wire them in series to take into account the factory wiring, using the current controller
  2. Add another 80w panel and wire them in parallel but update the factory wiring, using the current controller
  3. Remove the 80w and install a 100/20 controller, update the wiring and a 200w panel (being the max size/weight I could install)

What do you think would give me best yield, all year round in the UK?

Many thanks for looking.

harrib0 asked
wkirby answered ·

1 Answer

Which solar panel

Sorry I know

this does not belong here but I want to see the results of the blog

but the link as shown below

how to access

I can’t find

to see live data from our test go to the Victron Energy homepage and click on Field Test – which you’ll find top left of screen, on the site-map black-strip.

Take a look at this video to see how our 4 panel arrays were set up for comparison-testing, and how the results can be compared.

ray-mont asked
ray-mont commented ·

1 Answer

How much Wp from solar panels can I use in the MP II?

I am planning to install 18 panels of 450Wp (Voc 49,7V Isc 11,32A), 9 connected to each MPPT 250/100 with 3S3P giving me these values: 149,1V 33,96A.

I was reading the datasheet for the MP II48/5000/70-50 and it says maximum 50A for Maximum AC input current.

I am not sure if I could use this MPII using 2 MPPT's at that Amps. Can anyone give me a hint on this issue? Thank you

tpwchr asked
tpwchr commented ·

1 Answer

Victron 175W panel junction box - extra bypass diode?

Here's a picture of the junction box on the back of a Victron SPP041751200 175W panel:


Notice the three diodes - yet only two panel sections (three tabs). The panel physically is an arrangement of 4 x 9; electrically connected in two banks of 18 cells each.

I'm wondering why there are two diodes rather than just one across the more positive panel half? (right-hand side in this view)

(Aside: the soldering job is not fantastic on these...)

benl asked
michelg answered ·

2 Answers

Output of solar panels

Hi. I bought 2 panels rated as 300w@30v. On a full sunny day, midday, my victron controller measured 254 w @ 19v, 13.1 amps? I then measured one panel only, I got, 154w@19v, 7.4 amps! Full sunny day! I believe these panels are falsely advertised? Can anyone assist me to ascertain whether these panels are faulty,? Or have I been scammed??

Thanks already.

fallingbear asked
michelg commented ·

3 Answers

Number of Cells in Series or Array Voltage. Which is more important?

I have reviewed manuals for several SmartSolar MPPT charge controllers. Section 3.3 "PV Configuration" lays out the guidelines for the solar array. It gives minimum, recommended and maximum number of individual solar cells in series, i.e. " Minimum number of cells in series: 72 (2x 12V panel in series or one 24V panel)".

Is the number of cells important or is this a generalization to get the user in the correct operating voltage range? That voltage range being Vbat+5 to 10-15% below the voltage limit.

For example, charging a 12v battery bank with a controller that has a recommended series cell count of 72. Using a single 24v panel, would it matter if the panel had 72 cells or 60 cells as long as the voltage is within the parameters?

I am using the Victron Energy MPPT Calculator Excel spreadsheet to determine voltage range vs temperature for individual panels.


coghst asked
childcarepro answered ·

2 Answers

Low solar wattage in full sun

Hi guys,

Have been trying to figure this one out by myself and by reading other posts but I’m not getting anywhere. Hopefully somebody here can help.

I live in a van and have the following setup:

160w Blackline solar panel

2x 12V DC 75Ah Batteries in parallel

Victron MPPT 75/15 (no Bluetooth for app)

Victron Multiplus Compact 12/800/35-16

Victron Battery Display

We spent the last two months in very warm weather. Most of the days in full sun.

Yet I haven’t seen the wattage go above 90 watts. I’m sure it’s not in float since it even stays fairly low around 70%.

Yesterday I left the van in the morning around 09.00 and came back at 17.00 with all appliances turned off. It was in full sun all day and yet it only charged from 63% to 78%.

The previous owner tells me that, on a sunny day, it should do around 150 watts and that he got to 125 watts in February. I’m now in Italy in summer and I am not seeing those numbers. Recently it’s even been not much more than 50.

The whole thing has quite an impact on the way we live because we end up driving a lot more simply to charge our batteries.

Hope somebody has an idea.


tomka asked
spirou commented ·

1 Answer

What do you think of this system?

Hi everyone, im setting up a new PV system off-grid and I would appreciate to receive some feedback of this configuration, for a consumption of about 5kWh/day. Thanks!!

-16x400Wp monocrystalline

-4x2,4kW pylontech US2000

-MPPT Victron 250V100A + display

-Inverter Victron MultiPlus-II 48V 5000VA 70+50A

-Victron Control Color GX

-Genset 5000W as backup

tpwchr asked
tpwchr answered ·

1 Answer

Leisure Battery not charging

I am running a 200W panel through a 75/15 MPPT controller charging a 75Ah leisure battery. This system is used in a motor home and has been fine for over a year, however recently the battery is no longer charging. I have checked all fuses and connections and proven continuity in the wires from the panel to the controller.

My leisure battery reads 12.4V on a multimeter, however as can be seen in the attached image the controller states this to be 13.77. (Have I interpreted the screen correctly?).

I am also getting only 1W and 0A on a warm summer day in direct sunlight. The voltage stated in the image attached is 20.24V however when I put a voltmeter across the terminals on the controller I get nothing.

Also does the wattage display what power the solar panel can harness regardless of what charge the battery has. So even if I were to have a fully charged battery this would still display for example 130W in good weather?


siddy97 asked
wkirby answered ·

1 Answer

Restring PV array to not exceed MPPT limit

I have a 150/60 MPPT with a string of 12 panels (Voc = 37.4 each). It's been in place for about 3 years, but about 4 or 5 times a year I get a VRM warning that the voltage is greater than 150V, which then clears after 30 seconds or so. I've never worried about this, assuming it was just a transient issue. However I've just read @Guy comments on other posts that even if it a couple of volts over 150 then I must immediately switch off the device, and reconfigure the strings. I don't know how they are currently configured, but am I right that if the voltage is maxxing out at just over 150V , then they will be in 3 parallel sets of 4 series panels. So must I change this to 4 parallel sets of 3 panels, which will bring the max voltage to 114V which is well below the 150 limit? What is the downside to doing this?

ant asked
Paul B answered ·

3 Answers

Solar panel work in parallel but not in series string

Hi all

I'm trying to help out a friend with a solar panel issue, it's 4x 100W 18V panels.

One of the panels doesn't seam to work in a series string, however it works just fine when connected to the controller on its own, going over 17V around 4A, my conditions wasn't perfect.

The other 3 panels work just fine, I can string them in series, but as soon as I add the 4th one the string doesn't work, I even tried to swop it around to give it another position in the string. I also tried it just with a string of 2 panels but still nothing.

All these tests were done on my Smartsolar 100/20 and I know the controller is good, since I have similar size panels which works as expected.

What can be wrong with this panel, can it be something simple like a fuse or something and is it easy to fix? I never opened a solar panel before.


bigboy529 asked
michelg answered ·

4 Answers

Can I combine a Blue Smart Charger and a MPPT BlueSolar charge controller

I have a 12V Optima Yellowtop AGM battery in my 4x4 as a secondary battery which is connected to a 75W solar panel via a MPPT 75/15 BlueSolar charge controller. When my car is parked inside I want to connect the battery to my IP65 Blue Smart Charger. Do I have to disconnect the solar panels or can I leave them connected?

hans-van-rafelghem asked
Ed Baak answered ·

2 Answers


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