Newbie: Solar Charge Controller Advice Please

Hi to all the members here

I was hoping to ask for some advice please (before spending a lump sum of money).

I am trying to decide whether it’s worth spending a small fortune on a Victron SmartSolar MPPT 100/50 charge controller or just buy a cheaper solar charge controller. As a man who knows nothing about this, I noted that they work faster, prolong battery life for people who are novices like myself, will function more efficiently when there is less sunshine, and this is important to me when my battery bank is very small.

But I noted if I buy the Victron 100/50, then with a 12 volt battery bank, I am limited to 700 Watts in total of solar panels. If I move up to 24 volts, then I am limited to 1400 Watts (with this specific Victron model). It does not go beyond 24 Volts (this model, which is already quite an expensive device).

My question is, if I start off with a 12 volt battery bank, with this Victron 100/50 and 700 Watts solar panels, which I connect (not me personally) to the main grid of the house, but later decide I want to add another 1000 watts of solar panels, then is it possible to have 1700 watts connected to the main grid of the house, and just alone the 700 watt portion to the batteries (this Victron model will only go up to 700 watts)? Is it complex to do it like this at a later stage?

I have read that it is entirely possible to have no batteries and just connect the solar panels to the main grid of the house, therefore I thought a small battery bank would be fine for now to use for a few hours at night or when there is a power outage (which is freqent).

I also thought of buying light weight solar panels of 2kg each of perhaps 100 Watts each and then connect them together. If they are light, then I can easily take them away from the house when going camping. I am just not sure how water resistant these ones are (I saw some are slightly flexible/bendable up to a point).

I have also read that it is possible to directly connect solar panels to an inverter. Does anyone perhaps know if the Victron 100/50 will allow this? Or must there be a battery connected? Do you think the inverter will get dammaged if connecting the solar panels directly to the inverter? Does anyone know if this Victron is rain proof?

Finally, may I ask a last question please? My idea of multiple small light weight 2kg solar panels connected to each other, and placed in the sun in the garden (a bit like camping) versus massive, heavy visible solar panels on the roof makes me think that there are no government registration requirements. Am I thinking correctly?

Many thanks to everyone for taking the time to read this and provide advice.

Thank you

Best regards

James

@Svarky, are you able to help James with his query?

Hi James,

It seems you are very new to solar so to help you really need get some more understanding - here is an article explaining the difference between AC and DC-coupled battery systems.

The Victron MPPT’s are DC-coupled solar charge controllers, these can only be connected to batteries, NOT to the grid. I would recommend you start with a 24V battery system using 2 x 12V batteries in series. Do not connect to the grid and use this as a simple solar/backup system.

If you are not experienced with electrical circuits you should get help from someone who is. Which country are you located in?

1 Like