What do you think i need ?

RV Jim

Newbie needing help
Joined
Mar 29, 2022
Messages
35
Location
Odem Texas
The thread title is a good indication of my experience. This is the question for the great minds here. The advice i am looking for is what do I need to build a complete solar system to run. I understand that specific watts and amps will be needed to be more precise but overkill is an excepted option at this time bearing in mind it has a 400 watt input. I would like to thank all those that reply in advance for your help and support. I would like to do this right the first time lol 😆
1. 2 or 3 small personal size 12 v fans. Plus a 12v MAXX air roof vent
2. Possibly a 12v TV
3. A 12v cooler.
4. Several interior/exterior led lights
5. A 120 v Cpap machine.
6. Possibly a 120 v small 1500-1800 watt cooking system.
7. A shore power/ generator connection to augment cloudy days that would not/could not make the solar system charge.
 

TomC4306

Solar Addict
Joined
Mar 2, 2021
Messages
303
I think you need to read more first. Search the forum for energy audit.
 

Rednecktek

Photon Sorcerer
Joined
Sep 8, 2021
Messages
1,838
Location
On a boat usually.
Well, I'll start the default answer to these questions and we can work from there. Here's you To-Do list:

1: Power audit! This will give you some important information on how big your inverter needs to be as well as how much battery capacity you'll need. There is a link in the FAQ section (I think, or someone here will post it shortly) so fill in the blanks and see what it comes up with. You'll probably need some sort of Kill-A-Watt to get accurate measurements. Are you going to be running a 12v system? 24v system? 48v system? What are the specs on your solar panels? VoC? Vmp? Being as this is a new build, throw together a wish list of what you want and estimate on the high side.

1a: Where do you live? Speccing out a system for Scotland is a LOT different numbers than Arizona due to the amount of light you actually get. Someone here can post the link to the PVwatts.com or JCR Solar Uber-Sun-Hours calculator sites to help figure out how much you'll have to work with. That will be a box in the Power Audit form.

2: Parts list: You don't need a make & model list, just a parts list to start from for reference. You'll need an inverter, a MPPT charge controller, fuses, shunt, buck converter, batteries, wire, etc. Once you have a basic list it can be fine tuned to make & models after that. If you're looking at the All-In-Ones check for correct voltage outputs (120v or 240v Split Phase for North America, 220v Single Phase for European type areas) and make sure it has enough capacity for a little bit of growth and fudge factor.

3: Budget!: Steak is great but doesn't mean anything if your wallet says hamburger. :) Figure out what you're able to spend now vs what you'll have to cheap out on now and upgrade later.

4: Tape measure! Figure out where you're going to stick all the stuff you'll need. A dozen 3000AH batteries sounds great until you're sleeping on the floor because there's no room left for a bed. Is there a compartment that can house all this stuff? Will the server rack batteries fit? Are you going to have to make space? Physics can be pretty unforgiving.

5: Pencil out what you think you need and throw it at us so we can tell you what you've missed (because we ALL miss stuff the first go-round :) ) and help figure out which parts and pieces you're going to want to get.
 

Rednecktek

Photon Sorcerer
Joined
Sep 8, 2021
Messages
1,838
Location
On a boat usually.
There's no such thing as a One-Size-Fits-All solar system, anyone who tells you otherwise is in Sales. Your system will be exactly that: YOUR system. If designed and built properly it will fulfil your needs, but not mine or TomC's or Will's.

Because of this there is a LOT of math and number crunching that has to happen so you don't end up like people like me who have spent $realmoney on things that didn't work. Yes, it's a bit of a PITA but it's a CHEAP PITA in comparison.

It also gives you the ability to start out with a "Wish List" of things you'd really like to have someday running of your system. Hot tub? Cool. MargaritaMaster 9000? Go for it. You will be spending some time whittling down from what you "Want" to what is "Right" and hopefully not "Alomst".

Spend some quality time on the power audit, it will save you $Realmoney when you are finally ready to pull the trigger. It's worth it, trust us. :)
 

RV Jim

Newbie needing help
Joined
Mar 29, 2022
Messages
35
Location
Odem Texas
While waiting for some awesome advice I found a calculator(Renogy) that that says about 350 watts with 400ah battery(s) could last 6 hours and recharge in my 5 ish hours of full sun time. So now I need to check ALL items I plan to power with 12 v that I will fudge up 1 full number. Next question is how big of an inverter could/ should I use safely. The better half has a 9/10 in one 1800 watt cooking(small) table top oven she is pretty much set on having. I'm going to try and convince her to shore power ONLY the oven but WE all know that may not fly with her. Her reasoning(and I kinda agree) is the purpose for the converted cargo trailer is to be able to stop anywhere we want not just in facilities with 120 v power.
 

rmaddy

Full-time Solar-powered Trailer Life
Joined
Nov 16, 2019
Messages
3,395
Location
USA
Use this to do your energy audit. It will tell you how much battery, solar, and inverter you need based on the info you enter:

 

rmaddy

Full-time Solar-powered Trailer Life
Joined
Nov 16, 2019
Messages
3,395
Location
USA
The better half has a 9/10 in one 1800 watt cooking(small) table top oven she is pretty much set on having.
Propane is a much better option if you don't want to be plugged into shore power every day. Propane heat, cooking, and hot water is way more efficient than electric heat, cooking, and hot water.
 

Rednecktek

Photon Sorcerer
Joined
Sep 8, 2021
Messages
1,838
Location
On a boat usually.
Propane is a much better option if you don't want to be plugged into shore power every day. Propane heat, cooking, and hot water is way more efficient than electric heat, cooking, and hot water.
The general consensus in the solar world for anything generating heat (water heaters, ovens, heaters, etc) is Anything But Solar because it's such an insane draw on a battery. For a point of reference, the American Bog Standard Electric Heater is a120v 1500w heater and will drain a $350 100Ah LFP battery to dead in about 45 minutes.

That same battery would run the fans and pump on my diesel heater for 20 days.
 

HRTKD

Boondocker
Joined
Apr 24, 2020
Messages
7,698
Location
Somewhere South of Denver
The better half has a 9/10 in one 1800 watt cooking(small) table top oven she is pretty much set on having. I'm going to try and convince her to shore power ONLY the oven but WE all know that may not fly with her. Her reasoning(and I kinda agree) is the purpose for the converted cargo trailer is to be able to stop anywhere we want not just in facilities with 120 v power.

It can be done but you may need to upsize your battery bank, inverter and PV. As a test of my 560 Ah battery bank I charged my EV. In three hours I went from 100% down to 39%. The inverter was producing 1900 watts on the AC side when I checked on it (this is not watt hours, only a discrete measurement, a snapshot). Your oven won't be on that long, but I'm providing my experience to give you an idea of what can be done.
 

MisterSandals

Participation Medalist
Joined
Nov 5, 2019
Messages
6,257
Location
Silicon Valley
The better half has a 9/10 in one 1800 watt cooking(small) table top oven
To run this for 1 hour each day, you need to provide 1800Wh. The inverter will use about 15% of that so figure about 2100Wh

2100Wh / 12.8V = 164Ah of battery
build a complete solar system to run.
2100Wh / 5 solar hours = 420W solar panel

This is just for your cooktop for an hour and assuming near perfect efficiency.

You need to figure this out with everything you expect to power each day.
 
Top