EG4 6.5 Question - MPPT/Panel Balancing

[Moto]

New to solar... Just trying to price/plan a system.

I just want to verify it is OK to have a different number of panels on each MPPT input on the EG4 6500 EX-48?
I assume each mppt works independent of the other, but I wasn't able to find anything other than max inputs in the manual.

In my head most pallets come with 30 panels per pallet. To get things to work I'd do a couple of rows of 8 and a couple of rows of 7. (Probably15 panels per EG4 6500 EX-48)

To rephrase my question....
On most all-in-one units do the MPPTs inputs work independent of one and other as long as you fall in the specified voltage/current range of each MPPT?

Background:
I'll probably have a few more brilliant questions before everything is said and done.
- I'm trying to figure out if I want to install a solar system at a manufactured cabin this summer or next. I have an existing electrical service in a shop about 150ft away. It looks like it is sized at 100 AMP. I'm hoping to go solar and use that as backup for a couple of EG4s or similar.

The trouble with the cabin is I don't really have a good grasp on how much power it will take. I don't have a full appliance list and we have some old appliances from a farm we demolished. I back of the napkinned things but I think I was over sizing the system given the place will mostly be used in the summer. Was planning 12000W to 14000W worth of solar and maybe 20KWH of batteries.

Really the washer and dryer set is the only thing I'm worried about. They are both near commercial sized speed queen units out of the old farm house. (going in the garage that will share power)
The cabin is all new stuff and I'll probably put in a 24000 or 18000 BTU mini split heat pump. ~400 sq/ft

 

[mountkay]

is OK to have a different number of panels on each MPPT input on the EG4 6500 EX-48

Yes.

I think I was over sizing the system given the place will mostly be used in the summer. Was planning 12000W to 14000W worth of solar and maybe 20KWH of batteries.

I am currently in an off-grid home. I have a similar setup to what you are talking about. 2x EG4 6500. 6.8KW solar. 20KWH batteries.

Currently with the blower for propane heating, heat tape for the well line, fridge, and lights, and minimal well pump use, I use about 2KW per day.
***But the inverters themselves use about 3.5KW per day. ***

It’s winter so I have to wait for a sunny day to fire up the hot water heater to shower and run dishwasher if I want and eventually once I get a washing machine, do laundry.
(Planning on adding 2x more batteries for next winter and maybe an additional smaller inverter to run critical loads so I can shut off the EG4s when needed).

But on a sunny day my 6.8KW panels is more than enough for 150deg water, a shower, dishwasher, and well pump. I even run a 1.5KW electric heater at the same time.

Overall, I would say it does sound like your system is oversized, especially if you will be using it mainly in the summer.

Since you are planning this to be off-grid, you will most likely have your panels oversized for your batteries like I do so that you can survive though a few days of clouds. That means on a sunny day you will have tons of excess power. For doing something intermittent like laundry I think you will be fine to pick a good day out of the week when you can use excess solar or wash when you know your batteries will be recharged soon.

If you want to get a deal on a pallet of panels, it could be worth it, and then you could do less batteries to start and add more later on.

Only thing is with that many panels you may be charging the batteries at too high of an amperage. Someone from Signature Solar said they can handle up to 100amp, but they wouldn’t recommend more than 60amp, and they only do 40amp at their facility.
You can limit this with the inverters tho.

If your heat pump uses ~2.5KW I think that will be fine for cooling, but I’m not sure how much you could rely on it for heating. (Cooling will be on hot sunny day when you have plenty of power, but heating will be on cloudy shorter days near the edge of summer season when solar is less).

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