Building new project.. solar battery backup... need now help


I am giving the steps to the solar power, so I read and got the general idea of what I want (thanks to the lot of guides here), I made a diagram of the system I need, then the time when I need to ask the experts is here, with choosing the correct hybrid multi-mode/charger, and how should I calculate how many panels and what model must I get.
Here is the pictures
Thanks in advance.



Hi Hikove,

A few problems with your diagram.

  • The multi-mode inverter already has the automatic transfer switch built in.
  • You do not really need a generator as the grid is already a backup power source.
  • If you are not experienced with installing and programming multi-mode inverters I would not recommend you do this yourself.
  • Sizing systems correctly is not easy and you should get an experience solar professional to build the system.

Where are you located?



Thank you for your words.
Sure there are lot of flaws in there I need to read and learn a lot before buying anything. Just to clarify something, the public grid service is no t a backup source, it is the main source, the backup is the panels in case there is a blackout here in Venezuela. At night it should be a backup for the backup, but you are right, I should invest in backup batteries instead connecting the generator.
Of course, I won’t do it myself, but I need to buy it myself, so I need to learn all I need to learn to buy the system. As I don’t need too many panels because the needed power is not that great, I am investigating the micro-inverter ones.
You did notice the Automatic transfer switch in there, it is because the solar system will be the first backup plan, my intention is to let the solar system in stand-by, I don’t need it when grid is working, but sure, there is a lot of improvement to make, and here I am absorbing like a sponge.
Thnaks again for your words, I am taking notes.



Hi Hikove,

The mico-inverters are not compatible with the multi-mode inverters, I would not use micro-inverters as they will shutdown if the grid shutsdown and cannot ‘ramp’ down if the batteries are full (could destroy the battery). You need compatible solar inverter or DC solar charge controllers.

The multi-mode inverters from Victron already have the transfer-switch inside the inverter. You do not need an extra external ATS. The Victron Multiplus or Victron Quattro inverter is a good option. They have both the grid and generator AC input into the inverter ( 2 x AC inputs)



I would also recommend you use a Victron system with DC solar charge controllers. This way you can add more panels and more controllers later. Victron is compatible with many battery systems including BYD, LG chem and common lead-acid batteries.



OK. Understood.
Thank you very much.
Indeed after reading so more on microinverters, I didn’t like the limited output from them, example, the Enphase IQ7+ will run around 232 W per panel, even if this panel has a 350 W of maximum power, so the conclusion is going with normal inverters systems. I read about these victron models you just mentioned, indeed I think they are excelent choice for my needs, btw I took measure of my roof and I can only mount max 12 panels, 60 cell ones, then making my research what I really need is a really good efficient panels. I need to look for powerful and good quality ones. I think I cannot go further after 12 panels. What panels should I check out?
And regarding inclination, is it strictly necessary? I think the rain will be a problem but as I am living in 10 Degrees Latitude, I have the sun exactly over my head passing over me w/o shading or obstruction from nowhere, and my roof is flat. when I read I need to make 10 Degrees inclination following the sun, there is not need to do that, that is almost leaving them flat. Can I just mount them parallel to the roof?

I am watching the general picture with more clarity each time.
Thank you so much for the help.



Hi @Hikove

Your panels will get very dirty without any inclination, and they will not work very well. Especially if you are concerned about high efficiency, you should have them on a slight tilt at least.

If you want high efficiency, quality panels, you should look at Sunpower or LG.

Is it possible to import these products to Venezuela at the moment?




Yes, I was thinking about the running water and dirty too, it will be a problem.
You can bring here anything you want: cars, UltraHD huge TV, Industrial AC, Huge Generators, whatever, except equipment used for body protection in public riot: like gas mask, baseball bats or air guns, fire guns, knife, etc…
I am not sending directly to Venezuela anyway, I will get them to Florida first, then send them by ship to me.
The real problem for me is getting online stores selling this products and shipping inside USA to end consumer. Example, I was trying to get online store for selling SMA products and it is a pain… The ones selling them is always to companies and installers, the victron ones are easy to buy, they can be found in amazon. the LG panels are hard to get them, The online store always send you to installers and dealers offering installation service, but not selling the products alone. If you know online stores shipping to USA or inside USA w/o so much problems, I really appreciate it.
I haven’t read complete victron guide, but will I need another inverter?, like Fronius or SolarEdge? or with just the DC charge controller between the panels and victron is enough? I haven’t decide about DC or AC batteries yet, the most important for me is the battery must be ready and charged for back-up at all moment after grid shut down. what is the best option for my application?
My general idea is after grid is out, the system should provide essential charge, like standard lights, refrigerator x2, LED 60W reflectors x5, security system about 12 IP cameras and 60 meters electric fence energiser, no AC, no hot water needed in backup mode, when in need for the 1 HP water pump I will start the 8500 gas generator to help the inverter.
That is the complete map of the system, If I am missing something in the diagram, point it out please.
Thank you very much.



It seems like you would need a professional to design your system. Are there electricians or solar installers that you can get to design the system? This will save you a lot of trouble in the long run.



Yes I agree 100% with you Sr.
There are lot of electricians everywhere, but not lot of them can explain to you solar systems. So, I am here in this forum trying to get help from the ones with lot of experience.
I was reading the Victron Quattro manual and I think it is perfect, the Quattro doesn’t connect directly to the PV, the MPPT will charge the battery in DC-coupled mode and stop itself when battery is full, the Quattro will take the DC from the battery and used as backup when there is not grid available and if it detects power coming from the input 2 (Generator) will start using the power together with the battery, in case there is enough power coming from the generator will use the surplus to help the PV charge the battery. In case I want to use another inverter like the Fronius and charge the battery in AC-coupled mode I will lost the Input AC 1 and will be a completed off-grid system (I don’t want that). I first I was thinking in optimizers could be great because at sunset, when sun is almost gone, the panels will get partial shade from a water-tank and some HF-VHF antennas, I can move the antennas but I cannot move the water-tank, so I wanted to neutralize the shading with the SolarEdge optimizers, then I will need to use a SolarEdge inverter, but I won’t be able to use the Victron as I really want. Here comes the Charge Controllers in the picture. Then some question came in the game: What are the benefits in using the model with MC4 connection or the models w/o them. I read there are MC4 splitters to allow you connect the PV in parallel mode, because every PV you connect to the MC4’s connection available in the MPPTs will be in serial between them. Please, let me know what I am missing here, I will be thankful for it .
Now I need to search for a battery that could upgrade just adding another module time by time. And the most important thing, they should be available for sale in online stores in US.
There is something I don’t remember I have read on the Victron Quattro, Can it let pass through 100 amp or more from the grid to the load in normal mode?
I am investigating the OutBack power skybox, it has great option too.
I am sorry for being a bother, I am doing my homework, but the expertise from the professional in the area is always needed. And it is something I only can get on Internet, not in the field here. You could go the “Ávila” (It is a beatiful costal mountain to the north of Caracas) google it, you could go there and watch Caracas down and you won’t find solar panels in all the picture.People use lights with integrated panels and small things, but not complete systems, it is easier and cheaper to just go and buy a generator and use it with natural gas. I am doing it too, but at some point in the future I think natural gas’s pipe will suffer the same or worse like the national grid lines. I need to go a step further.
Thank you very much for all your help so far.
Thank you.