Looking for Battery & Solar sizing spreadsheet

smkettner wrote:
Just fill the compartment with battery and fill the roof with solar :B

x2 ... keep it simple :)

Hi,

With panels at as low as $0.26 per watt, covering the roof with panels may be the cheapest part of the solar system.

A proper energy audit is needed. The simplest way to do that is to use a monitor of some kind. For myself that was done originally by using a kill-a-watt meter.

johnm1 wrote:
Trust me ... I want to fill the roof with panels. My bank account on the other hand does not want that!

I am soooooooooo tired of listening to off-grid owners whining that they "designed" their system with spreadsheets, graphs, charts, and astrophysics aids...

"It doesn't work with a ****!"

Get an amp hour meter installed FIRST FIRST FIRST

Then live in your rig and get the 1st stage perspective of how much energy you consume nightly.

Add batteries. Forget about the panels for now - they come last.

Once you have stabilized your lifestyle with knowing negative amp hour consumption

THEN

Add panels. 50% of your battery bank capacity is going to be no-touchee.

Solar panels as a charging aid alone need to be sized much larger than if you have a generator. Same thing for 3-4 day outings. Smaller. Serious boondocking on solar alone calls for lots of panels. So does camping when overcast or clouds deduct from the "harvest"

This is the SOLE WAY you are going to end up close to what you want with a minimum amount of money.

Spreadsheets my ass. They are only useful for solar farms where matching panels with inverters and transformers is critical. And yeah, I did a ton of residential, off-grid, and boondocking installations.

Trust me ... I want to fill the roof with panels. My bank account on the other hand does not want that!

try here

https://tools.carmanah.com/src.web/GoPowerCalculator.htm?state=RvDiv

It has the different tabs to fill out should get you the info you need or most of it anyway

Just fill the compartment with battery and fill the roof with solar :B

Try this one Solar sizing by N8GS.
It is in xls format.

I have it but I can't get it to load. It's an Excel spreadsheet

never heard of the spreadsheet, although I imagine it exists.

let your budget and roof space dictate how much solar you get, it's hard to have too much, especially on an RV.

on sunny days, having too much means your recharged earlier... if you're partly shaded or it's cloudy, having too much means you get a bit of charging versus nothing

for sizing a battery bank, add up the amps for the gear you want to run, and multiply by the number of hours you want to run it. for AC loads on an inverter, take the ac amps and multiply by 10 to get a rough dc amperage.