Small Cabin Setup - Basic Plan/Hardware Review

[dotster]

I have a small cabin that gets used a few weeks a year. Today it has a single 100w panel and an old charge controller and a 12v LA battery that runs a few LED lights and a 12v water pump. Dad wants a bit more power so he can charge his laptop, run a small coffee maker in the mornings, and potentially run Starlink internet.

My current thought is to use an all-in-one (SPF 3000TL LVM-ES), used panels (santan 250w), and renology 48v batteries (RBT50LFP48S-US).

I am planning to wire up 6 panels in series (~225V) to get the voltage up to what is needed for the AIO (needs >150V to start per docs). The panels are cheap so we might do two groups of 6 for 3000w (if I am going to pay for shipping might as well load up the pallet). The panels are going to be on a ground mount behind the structure and have clear space around them so they can face due South. I wasn't planning on doing much in the way of batteries, potentially just one to buffer the AIO so it runs stable during the day when there is sun. The cabin has wiring and a small breaker box that I was going to wire into from the AIO to provide power to the lights and outlets and then do a 48V to 12V DC-DC converter for the water pump.

I am looking for a basic sanity check on the plan, will it work, and then secondarily is there anything that would significantly improve this for roughly the same cost/effort/complexity? I realize that 3kw in panels isn't matched well to 50-100ah of batteries but I am not looking to run the system or need power for long if there isn't sun.

Thanks in advance.

 

[MisterSandals]

That is quite a big step up in system size. Going to 48v for what looks like mostly a coffee maker seem like overkill. And the large AIO seems like overkill too for the listed power usage estimates.
The usual numbers bandied about here is 12v system up to 3000w inverter, though over 2000w the amps start to get gnarly.
You're on the opposite end of the spectrum of folks looking to run air conditioning on a couple 100w panels, a 20a pwm SCC and an old car battery.

But, you'll be solar rich while the sun is shining (maybe slightly overcast too) and will have the ability to run real appliance during the day and have room to expand (battery storage).

 

[Wibla]

Starlink uses GOBS of power (at least in its current iteration), we're talking >100W average, maybe up to 200W. That kind of power usage throws a wrench into the power budget real quick if he intends to leave it running full time.

My current thought is to use an all-in-one (SPF 3000TL LVM-ES), used panels (santan 250w), and renology 48v batteries (RBT50LFP48S-US).

Nothing wrong with that all-in-one, and the Santan panels are perfect for offgrid since they're cheap (depending on shipping - buy a full pallet, sell the excess locally), but I question the battery choice. Those batteries are expensive for what you get.

 

[dotster]

That is quite a big step up in system size. Going to 48v for what looks like mostly a coffee maker seem like overkill. And the large AIO seems like overkill too for the listed power usage estimates.
The usual numbers bandied about here is 12v system up to 3000w inverter, though over 2000w the amps start to get gnarly.
You're on the opposite end of the spectrum of folks looking to run air conditioning on a couple 100w panels, a 20a pwm SCC and an old car battery.

But, you'll be solar rich while the sun is shining (maybe slightly overcast too) and will have the ability to run real appliance during the day and have room to expand (battery storage).

Yeah, thanks for the data, makes a lot of sense. I kind of only want to do this once and not have a situation where my Dad adds a DC fridge, decides he is going to plug in a TV/DVD player, etc. I really see this as something that might trigger him spending a few months a year at the cabin vs the 1-2 weeks he does now.

 

[dotster]

Starlink uses GOBS of power (at least in its current iteration), we're talking >100W average, maybe up to 200W. That kind of power usage throws a wrench into the power budget real quick if he intends to leave it running full time.


Nothing wrong with that all-in-one, and the Santan panels are perfect for offgrid since they're cheap (depending on shipping - buy a full pallet, sell the excess locally), but I question the battery choice. Those batteries are expensive for what you get.

For the starlink the plan would be to turn it on, use it and then turn it off when not in use (likely a few hrs a day when people are at the cabin).

I was also looking at the new SOK 24v that are coming out next month, this bat had built in heater so I was kind of looking at it for easy of use (this place is cold and regularly is freezing late fall early spring).

 

[Delmar]

I would keep it simple and stay 12V, otherwise the next step is a big one. Find a car charger for the laptop, and a RV coffee maker.

Also stay lead (AGM) otherwise you have to worry about freezing temps while charging.

Do you have internet access from your phone? Can setup as a hotspot to the computer.

 

[dotster]

I would keep it simple and stay 12V, otherwise the next step is a big one. Find a car charger for the laptop, and a RV coffee maker.

Also stay lead (AGM) otherwise you have to worry about freezing temps while charging.

Do you have internet access from your phone? Can setup as a hotspot to the computer.

The battery I was looking at has integral heating to take care of the temp issue. Satellite is the only option for Internet, you have to drive 20-30 min to get a cell signal. I was looking at 12v and adding a few batteries and panels to the existing setup (nothing to really expand there without replacing it all) and really price wise a new charge controller and inverter ends up so close in cost to the AIO I am looking at that the savings on cabling make it a wash.

 

[Wibla]

I kind of only want to do this once and not have a situation where my Dad adds a DC fridge, decides he is going to plug in a TV/DVD player, etc. I really see this as something that might trigger him spending a few months a year at the cabin vs the 1-2 weeks he does now.

Satellite is the only option for Internet, you have to drive 20-30 min to get a cell signal.

Buy cheap, buy twice

With power enough to "enable" more creature comforts, and decent internet (as long as starlink works out, but I do believe they can make it work), I wouldn't be surprised if he spends more time there. I know I would ?

 

[dotster]

Thanks for the sanity check. I did check on getting a full pallet of panels from SanTan (thanks for the recommendation). Going to start getting a parts list together for all the small stuff to use to hook this stuff together.

 

[dotster]

System is in and working, thanks everyone for the feedback and help.