Reply
 
Thread Tools Display Modes
Old 07-10-2019, 08:34 PM   #1
Junior Member
 
Join Date: Apr 2018
Location: NC
Posts: 27
Need a good power chart to calculate solar

Want to add solar to my small Coachman 16b TT. Doing the planning now but can't find a good chart of what the power usages are on all the 12V items in the camper. I also plan to add a small inverter just for a little TV or radio/CD/DVD occasionally.


Anyone have a link to a good power usage chart?


Thanks.
__________________

Outsider is offline   Reply With Quote
Old 07-10-2019, 08:48 PM   #2
Site Team
 
Flybob's Avatar
 
Join Date: Oct 2014
Posts: 9,484
Have a look at the 12V side of life in the electrical section of the library. Library is in the green bar at the top of the page.
__________________

__________________

2015 Freedom Express 248RBS
TV 2015 Silverado HD2500 Duramax
TST Tire Monitors
Honda 2000I + Companion
2 100W solar panels
Flybob is online now   Reply With Quote
Old 07-10-2019, 09:24 PM   #3
Senior Member
 
Join Date: Nov 2017
Location: Dayton Ohio
Posts: 836
Need to learn the math.

P=IV. Watts=Amps*volts.

The 1500 watt hairdrye, microwave draws about 14 amps ac. Or about .150 amps dc. Wipes out a battery every 20 minutes.

Batteries are your issue. You need deep cycle preferably six volts, more durable. The more amps the better. Two Costco sixes are 230 amps. Size is always an issue you must deal with. You can only use 50% of the amps or you damage the battery.

100 watts of solar charges a battery 25 amps a day on a good day. That is not a lot. Likely close to your parasitic loads. Fridge, smoke detector, leds on things. etc. With only 1 battery and 100 watt solar there will be no lights the second night.

Plan ahead. Study the chart.
tomkatb is online now   Reply With Quote
Old 07-10-2019, 09:47 PM   #4
Senior Member
 
Join Date: Aug 2016
Posts: 1,209
Bah, it can be spit-balled easily.
What are you wanting to run and for how long?

I have 420ah of batteries, 600w of solar, and a 2k inverter. I run pretty much whatever, whenever. TV, pocket media computer, charging devices (wireless chargers for phones), night lights, micro for a min or two a day, hair dryer for 3 or 4 minutes every couple days.. battery was charged by the time we got back in the afternoon. Don't think it got lower than 95% SOC. Perhaps I over-did it. However, it's a scaling basis for you.
aeblank is online now   Reply With Quote
Old 07-11-2019, 08:46 AM   #5
Retired Panpsychist
 
Theo's Avatar
 
Join Date: Jul 2016
Posts: 198
Once you have your daily consumption total (12-volt side of life), you can think about the solar panel specs...but...output is dependent upon the potential solar irradiance available at the panels’ location. That means that in clear weather, on the same day, your panels will generate more watt-hours in southwestern AZ than in northern CA.

HERE is a solar irradiance calculator that can be used to find the potential irradiance for a specific location for each month of the year. Follow the instructions on the website to get a reasonable estimate for the watt-hours you can expect your solar system to deliver to your battery bank in a day. Note, again, that these estimates are based on clear weather.

As mentioned earlier, you will also need to size the amp-hour capacity of your battery bank to support your daily watt-hour draw and charge for the camping duration.

Think about the places you regularly camp (or may camp) and configure your panels to provide the watt-hours needed to cover a portion of your battery bank’s daily draw. Again, you will also need to think about the number of consecutive days you’ll be dry camping in order to size the array and battery bank properly.
__________________
Theo & Carol

2007 GoldenDoodle ("Cooper")
2020 Rockwood Roo 23IKSS
2015 F-150 SCab, 5.0L, 3.73, HD Towing Pkg (53A)
Theo is offline   Reply With Quote
Old 07-11-2019, 09:05 AM   #6
Senior Member
 
Join Date: Jun 2013
Posts: 334
Another suggestion on sizing is to buy an oversized controller so you can add panels if you find you need more. If installing 300 watts of panel, use a 400 watt controller, etc.
nayther is offline   Reply With Quote
Old 07-11-2019, 12:24 PM   #7
Senior Member
 
Join Date: Nov 2017
Location: Dayton Ohio
Posts: 836
If you live in an area with clouds, solar is not so effective. Like most of the United States.

Also, that favored campsite with the beautiful shade trees doesn’t work out well.

Some day we will have better batteries and solar panels.

You need lots of batteries today to cover bad solar days and nights.

Got to do the math. What do you need? Where do you camp.

Easy as stated, just use what you have and turn the generator on.
tomkatb is online now   Reply With Quote
Old 07-11-2019, 01:05 PM   #8
Junior Member
 
Join Date: Apr 2019
Posts: 26
What I read here

Basically solar is for keeping your battery charged as long as you don't use it.



Just another "Hey look at me, I'm solar"
& I am good for nothing.
campers302 is offline   Reply With Quote
Old 07-11-2019, 01:31 PM   #9
Senior Member
 
Join Date: Jul 2017
Location: Peoples Republik of Kalifornia
Posts: 3,914
Quote:
Originally Posted by campers302 View Post
Basically solar is for keeping your battery charged as long as you don't use it.



Just another "Hey look at me, I'm solar"
& I am good for nothing.
Wow another...hey look, I know nothing about solar!


I have 700W of solar, I can recover from multiple days of no sun in one day with my 2 BattleBorn batteries. Never need a generator.
__________________
2017 Coachmen 233RBS
2018 Ford F150 Lariat 3.5 Eco
"Common sense is not very common"
babock is online now   Reply With Quote
Old 07-11-2019, 02:02 PM   #10
Senior Member
 
Join Date: Nov 2017
Location: Dayton Ohio
Posts: 836
See! Got to understand the math.

If you live in a desert state where the sun always shines and ac is not needed.

And, you have $5,000 worth of solar collectors, controllers, monitors, batteries and wire and no residential fridge solar is great. Sign me up.

Last year on spring vacation we needed heat(furnace) and it rained for six days or was cloudy. Plus I like cold beer. For me, it would not work.

I want the solar merit badge.

Got to plug in somewhere.
__________________

tomkatb is online now   Reply With Quote
Reply

Tags
power, solar

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



» Featured Campgrounds

Reviews provided by


Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 02:43 PM.