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Noob system questions semi-offgid?


I have a few questions, i do not know if everything is feasable and at which costs /Equipment. So any advice is appreciated.


Currently I have 10 kVa of SMA Solar convertors and around 13800 wp of panels. Producing around 12500 kWh yearly. This 10 kVA is grid tied, and a 10 kVa connection is the largest connection that is allowed as standard where i live, I applied for an exception to 20-25 kVa, but then I have to go to a hourly dynamic pricing contract.

My home usage is around 4000 kWh year. Quite stable at around 10-14 kWh Day

I have an EV, battery of around 50 KW, Needs around 80 kWH / week. The car is at home 3-4 days a week during daytime, and can be loaded with a smart charging station primarily on solar power instantly.

I have some larger power equipment, electrical engines of around 10 KW, averaging 2000 kWh yearly, not included in the standard home usage. I can try and use this as much as possible on sunny days, using quite a bit of instant solar power.

What do I want to achieve:

Become more autark and use as much of my own produced electricity as possible or at least be able to sell enough to the grid (around 4-1 ratio) to buy back the amount that I need myself.

Would be nice to be able to connect a smaller generator for cases of emergancy, and preferably the system has to be able to provide power to the house in case of an power outage.

I need the batterystorage solution to be able to provide around 5000 watts back to the house / garage / grid . 10000 would be nice.

Extra information:

I do have to room to put another 15000 wp of panels on another roof, but if I do not get approved to get a larger then 10 kVa connection, I can only use this a offgrid or semi offgrid set-up.

Any tips for me? Alsothe amount of batteries that would be recommended/ and the minimal amount to get started? Thinking aboutb pylontech US5000’s or similar.

joost asked

0 Answers

System Design Questions

My install in our Riverstone 5th wheel consists of the following:

(2) SmartSolar MPPT 150/60 solar charge controllers

(2) MultiPlus 12/3000/120-50 Inverters

(1) Lynx Power In

(2) Lynx Distributors

(10) 200 watt Rich Solar panels

Cerbo GX and GX Touch 50

Victron 120-240/100A Autotransformer

(8) BB 100AH LiFePO4 batteries

Orion TR Smart 12/12 30 amp iso.acted smart charger

The inverters are already hanging in the front pass-through, and the DC-DC charger, MPPTs, and DC In, DC distributors are mounted on a board in the front generator compartment above the door on the front wall. The Autotransformer will get hung next to the inverters.

- I plan to use 2/0 cable for the interconnects between the cells, and 4/0 cabling between the battery bank and the DC in. The battery output to the DC In will have a Blue Sea 600 amp disconnect and a fuse. The battery will be connected in one bank fo

- I also recently installed an Onan 6500 watt commercial RV generator (rig had generator prep option so the install was pretty straight forward).

- I plan on wiring two pairs of 10 AWG wiring from the solar panels to the charge controllers (wired in two banks of 5 panels). I already have a breaker enclosure and (2) two pole breakers to be able to disconnect the input to the charge controllers).

- I plan on using 2/0 cabling between the Lynx Distributor and the DC input to the inverters, and each will have a Blue Sea Systems 600 amp DC disconnect switch.

- For the DC-DC charger I plan on running 6 AWG cabling from my trucks alternator (2019 F-450, has dual alternators rated at 397 amps), to the bed of the truck near the 7 pin and utilize an Andersen connector.

Questions I have:

1 - what size cabling between the inverter AC output and the autotransformer input and from autotransformer output and AC distribution panel?

2 - Is a breaker needed between the inverters and the autotransformer, and between the autotransformer and the AC distribution panel?

3 - In your video you mentioned you ran the solar cables from the roof through the forward gray tank vent. How did you exit the vent pipe once inside the rig?

4 - For the DC-DC charger, how did I route the wiring from the DC-DC charger to the bed of the truck? Can I just push a fish tape and try and follow the trailer side of the 7-pin wiring?

5 - With the DC-DC charger installed, do I need to disable the charging wire coming from the 7-pin?

6 - My Riverstone already has a factory inverter installed that runs the refrigerator, TV, recliners, and a few outlets and I don’t plan to mess with that setup. Any issues there?

7 - What size disconnect do I need between the battery bank and the Lynx DC in?

8 - I am considering adding a lead acid battery to start the generator - what would be the best method to charge that and the house bank while the generator is running?

9 - The rig came with 1 factory solar panel and charge controller. I removed the factory panel and will be removing the factory charge controller - once I find it.

10 - I assume I don’t need to mess with the factory battery charger - or do I once the MultiPlus inverter chargers are up and running?

11 - What size fuse am I looking at for the battery output to the DC In.

12 - What is the best method for connecting the inverter AC output to the breaker panel in my rig?

I am sure more questions will pop up, and I really could use a wiring diagram showing all of the interconnects, breakers, disconnects, etc.

Please let me know what your design services will cost and how to move forward. Additionally, what would it cost to have you come out here to CT and help me do the install?

I already have pretty much everything I need, with the exception of any breakers needed on output side of the inverters, inverter output cabling, and a couple other little things.

I was a nuclear electronics technician in the Navy for 20 years so I am pretty savvy on this stuff, but want to make sure I do it right the first time.


ct-mike asked

0 Answers

Three phase solar system to home



Could this type of set up work as a one phase and three phase home solar system? Does this plan have any problems or something to fix?

Im not the best one to create professional electrical circuit diagrams.

All help will be useful! Thank you!

crimu asked

0 Answers

Marine Electronics System Design & Installation Help / Periodic Resource

Hi Folks,

Long time listener first time caller... : ) Have been lurking here for the last year plus and thanks for the support and community here.

I bought and live aboard a 37ft sailboat as of a year and a half ago. Have been doing projects and making upgrades in anticipation of cruising the boat long term / off grid. I've grown increasingly interested in electrical systems, have already made some upgrades to the boat here including a Multiplus II and some other upgrades and reconfigurations, and really I'm really eager to continue to gain more competency here.

I've learned a lot so far, but I consistently find myself up against knowledge gaps - especially with electrical - that end up burning way too much time and way too much energy spinning my wheels reading manuals and haphazardly trudging through misc online resources to try and answer questions and decision make toward a clear path forward... often ending up without clear answers or a path forward.

As of this winter my existing AGM batteries are toast. I need to make some moves here in the near term as I'm moving back aboard ASAP and getting the boat back in the water. I'm leaning toward a move to LifePo4 house bank and the requisite system upgrades to build, charge, operate, and maintain the system safely and efficiently. I'm making progress on my own - I think - putting info for system design together but have again found myself wasting too way too much time on questions that I'm sure are quite simple for the right person.

Is there a qualified marine electrician or marine electrical company out there familiar with Victron products than can provide periodic consultation services while I design and build my system?

I'm more than happy to pay for this, it would save me so much time and give me so much more confidence. I'm enjoying the research, diagramming, and learning thats coming with this and am trying to be as thorough and organized as possible - but I'm painfully aware that I need some expert advice to move this forward safely and confidently.

System currently includes: 30A shore power, 3.5kw Generator, Multiplus II 12/3000/120, Victron BMV, 2 - 30A Blue Sea Distribution Panels, Blue Sea DC Distribution Panel, 420 Ah of (toasted) AGM batteries split between house / start, 1500W Lofrans Windlass, Raymarine Instruments, Refrigeration / Compressor, Misc other DC consumers.

Upgrades I have and are not installed, or plan to buy install: LifePO4 Cells, REC or Orion Jr BMS, Tyco Contactors / Disconnectors, Victron Orion DC >> DC Charger, 400W - 600W of PV Array, Victron MPPT Controllers, Balmar Alternator, Balmar or Wakespeed Alternator Regulator, Galvanic Isolator, 30A Blue Sea ELCI.

If there are existing resources out there you can recommend, please do. If you're an individual out there that might be the right fit to help guide me through this I'd love to connect and try to figure out a way to work together toward designing and me executing on this.


// Phil

panema asked

0 Answers

Victron system diagram for my conversion

What to choose for a BMS? I've seen diagrams with the VE.Bus, others with the Lynx BMS, others still with the BMS 12/100.

Does it make sense to plan two Orions 12/30 to leverage on the powerful smart alternator or it's overcomplicating the solution?


Context: I have a Mercedes V-Class (W447) where I want to replace an inverter of 1500W power (peak 3000W) and the "dead" battery. It is a "Luxury Van", rebuilt a few years ago, with a very large TV, coffee maker, Playstation, etc. I would like to install a Victron system and convert to a recreational vehicle for short weekend adventures. This is my first design composed from several sources, it may be incorrect.

vbo asked
vbo edited ·

0 Answers

Will Quattro 48/3000/35 Work for My Soar Setup?

A few years ago I bought a Quattro 48/3000/35 in hopes of one day putting together a small off-grid system for a small metal garage/guesthouse. Well, I recently ended up purchasing a 4800w system that needs an inverter/charger, and I'm wondering if the Quattro 48/3000/35 would be sufficient assuming we occasionally run the load at full capacity (which is not likely to ever happen). Would it be better to add a second unit or even upgrade to a larger unit?

smalltoid asked
shaneyake commented ·

0 Answers

How to integrate new features on Cerbo GX


I need to integrate a new feature on Cerbo GX device (adding a new function to a relay). The coding part looks not that complicated, I already have an idea about how to add the feature.

But my question is: how should I proceed ?

1) Should I add my feature on my Cerbo GX device, test and "clone" the image to be able to later, upload the image on other devices.

2) Should I build the OS image from source with my feature in it ?

Thank you for your help.

stabilo asked

0 Answers

Lithium SuperPack drop-in replacement feasibility

Hi, I've been reading though all the posted questions but can't find a clear answer.

I'm considering replacing the current AGM house bank on my boat with SuperPack batteries, and I'm trying to understand what it would involve.

Below an attempt to visualize my current setup:


I understand that I'll have to replace the shore charger for a Lithium one, but beyond that, is there anything else I would have to replace/modify, or will the SmartPacks be a simple "drop-in" replacement?

My main doubt is:

Since the BMS is integrated, what will happen if the batteries are fully charged and the engine/alternator is running? Is there a risk the BMS will trigger the over-charge protection and disconnect all the loads (e.g. loosing plotter and instruments when approaching an anchorage/marina)

Any other suggestion/input is highly appreciated, like: does the Argo Fet still make sense with the SuperPack, or should I replace it with an Orion-Tr DC-DC charger? Do I need a separate external BMS to protect the batteries from overcharging?

Thank you!

badrock asked

0 Answers

Looking for engineering support

Hello, I have built a three phase 60Kw system with approximately 300 panels, four wind turbines. The system is based on 6 Victron quattros. This is a three phase system with two quattros in parallel per phase. 300KwH of batteries.

The system works well, but I would like to work with a real electrical engineer (aka not me) to document the schematic, move the DC system to a busbar system, implement a couple of automations, make sure all the system safety and managment are in place and ultimately make the system such that it can be built out in a container and shipped to specific sites.

Do you have any recommendations of individuals or companies who could help me ?

pierre-samec asked

0 Answers

Sanity check please...

Hi there,

I'm wondering if I can get some feedback about my proposed system. Diagram is below. My concerns are about whether I should be using the Cyrix-ct battery combiner instead of an ArgoFET isolator. Should the MPPT controllers feed to the start battery? as well as the house batteries?

Larger version of pic at DC supply and charging.pdf


marc-kelly asked
marc-kelly edited ·

0 Answers

Request: Blue Smart - Add tail current to expert mode

Can the devs please add the ability to set end of absorption tail current in the Blue Smart charger lineup when in expert mode? This would be extremely helpful to prevent premature switch to float without relying on fixed absorption and the risk overcharging when doing that.

It appears that this was at least thought of at some point given in the Absorption duration settings it directs a user to disable the tail current setting when using fixed absorption.

If this is done PLEASE allow tail current setting to be dropped below the .50% level that is in the smart shunt (and maybe other products). Odyssey batteries want to see .02% of tail current to end absorption.

captain-mike asked

0 Answers

looking for help 3 phase and home plus bus

i am looking at converting my home and business to full solar and wind power. But i but i need some major power for bus fleet 3 buses and soon 2 cybertruck (tri motor) (180*est kwh each) and based on buses using 446 kwh x 3. each charge needs to be at 100 kw/hr each. Plus 360 kwh at charge rate of 50 kw/hr per charger, plus home usage 25kw/day and garage(bus maintenance) using 70kw/day (7am-5pm)(10hrs) so need a discharge rate of approx 400 kw/hr mostly in off peak time 10pm - 5am and 12kw/hr during daylight hours so my estimates say i need 3000 kwh/ 450 kw battery. could you size up a system with 2 wind turbines and solar array plus battery with a option for 2 extra generating sources i.e. GENSET &/ hydrogen

rjo71342 asked

0 Answers

Is it allowed to interconnect the midpoints at an 24V system (4x 100 Ah LiFePo4)?


is it allowed to interconnect the midpoints at an 24V system build up with two parallel lines each consisting of two Victron 12 V 100 Ah LiFePo4 batteries in series? Regarding the manual it is forbidden.

For reliability reasons I want to connect a Victron balancer on these midpoint.

Thanks for the help.



hagen asked

0 Answers

Constant voltage

I have a motorhome with an onboard control board that includes charging logic from a mains charger and or solar supply. The current panel control is terribly inefficient and I want to put a 75/10 in there to allow significant charge on dull days, by increasing board voltage/capacity although max current is 10 amps-. Current system charges at 2 amps on the brightest possible day but I can not add a new panel as the vontroller is very limited.

Anyway ideally I want to provide a constant voltage to the board from the Victron, say 13.8 volts give or take, so the existing board could then do its charge thing-split charge batteries and control output to them etc.

Can the Victron 75/10 be set to do this. Ideally there would only be the one pair of connections to the board. Although I could connect load to board and battery output to the battery I would rather not as I wonder wether when I plug into mains and the onboard battery charger is powered it would cause problems.....It also needs to be considered that there is another charge system, the alternater, during drive times, this charges vehicle battery, and leisure battery once voltage is over about 13v.

wingphil asked

0 Answers

Connecting two sets of Multiplus 24V and 12V to one Octo GX?

We have three MultiPlus 24/5000/120-100 230V and two MultiPlus 24/3000/70-50 120V on our new boat under construction, all connected to one battery bank. We would like to connect the second group of MultiPlus to the OctoGX with a MK3-USB. There is no real manual for the OctoGX. In the manual for the CCGX under the heading Connecting multiple VE.Bus systems to a single CCGX, it says if you do this, "The CCGX will not send proper data to VRM any more. The Venus GX does send information of both systems to VRM: its therefor better to use a Venus GX for systems like this."

My question is does the Octo handle this more like the Venus GX or more like the CCGX? And second question is could the new CerboGX handle this situation as well or better than the Venus?

Thanks in advance for any help.

Wayne & Christine asked

0 Answers

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