Reply
 
Thread Tools Display Modes
 
Old 06-25-2017, 07:36 PM   #1
New Member
 
Join Date: Jun 2017
Location: Houston, Texas
Posts: 4
Year: 1994
Chassis: Bluebird
Engine: TC2000
Solar Power Questions



I am considering this kit for my Skoolie. My question is what type of batteries should I be looking into? And is this sufficient solar to be completely off grid, if say we are using tv and Internet all day?


Sent from my iPhone using Tapatalk
earthlingdale is offline   Reply With Quote
Old 06-25-2017, 07:48 PM   #2
Bus Nut
 
Join Date: Oct 2014
Location: Kent, WA (Seattle)
Posts: 411
Year: 1987
Engine: 6.9L Diesel
Based off the questions you're asking, you should probably start with investing your time before your money into

1. https://handybobsolar.wordpress.com/...ging-puzzle-2/

and maybe

2. https://www.amazon.com/Managing-12-V.../dp/0964738627


They both have helped me immensely. If all goes to plan I'll hopefully be wrapping up my solar project by the end of this month, and have a nice walkthrough by the end of next month. But we'll see about that, I've been off my game with documentation due to life.

I did end up buying some renogy panels due to the simplicity of buying them from my bathroom, but I digress. Start with handybob solar, and put some time and research into it. There's a lot of good resources out there. I myself made a lot of impulsive purchases early in my planning with the assumption that it would magically materialize my ambitions, but trust me when I tell you that research time and planning should precede any purchases.
TAOLIK is offline   Reply With Quote
Old 06-25-2017, 08:32 PM   #3
New Member
 
Join Date: Jun 2017
Location: Houston, Texas
Posts: 4
Year: 1994
Chassis: Bluebird
Engine: TC2000
Thanks this is very helpful. So do most Skoolie owners get meter readings to calculate your precise power needs?


Sent from my iPhone using Tapatalk
earthlingdale is offline   Reply With Quote
Old 06-25-2017, 08:48 PM   #4
Bus Geek
 
Join Date: May 2016
Location: Eastern WA
Posts: 5,542
Year: 2002
Coachwork: Bluebird
Chassis: All American RE (A3RE)
Engine: Cummins ISC (8.3)
Rated Cap: 72
What Taolik said.... Good advice.

I use a device called a Kill-A-Watt meter to measure real world power consumption of the devices that I will be using in my conversion.

The first steps are learning and determining what your actual power needs are. Ten you can pick the system size to fit your needs.

Renogy kits may not be absolutely the cheapest way to go and they may not be "caddilac" but they are reasonably well engineered kits of components and have good technical support.

If you want to take the time to learn solar well then you can shop your own components and save some money. BUT unless you want to take the time and effort to learn the subject well, I think that a Renogy kit is a great way to get the right pieces to work together.
PNW_Steve is online now   Reply With Quote
Old 06-25-2017, 08:56 PM   #5
Bus Nut
 
Join Date: Oct 2014
Location: Kent, WA (Seattle)
Posts: 411
Year: 1987
Engine: 6.9L Diesel
Meter readings are a great way to start.

I'm a little short with time so I'll be short, but

A killawatt will go a long way in educating you with your electrical draw from basic appliances. You can find one by clicking here.

The idea is that you will list all the appliances you plan to use, and how many hours you plan to use it every day (15 min would be 0.25 hours). You then multiply the hourly usage by the hourly electrical draw (ie: 0.25 hours of a 1000watt rice cooker would be 250 watts). And that will determine your daily electrical need. say 250watts for the rice cooker. If it is inverted, divide that by 0.8 to compensate for inverter inefficiencies (I assume 20% inefficiency to be safe) 250/0.8=312.5

Once you understand your daily electrical need, determine your needed amperage every day. 312.5watts/12v = 26.04 amps. Assuming you use 2 or more flooded 6v batteries (the solar standard from what I understand), you will want to make sure you plan around exhausting your batteries no more than 50% on average. This means that if you use 2 6v 220ah batteries in a series to make one 12v 220ah battery, you only want to use 110ah. the rice cooker uses 26.04 amps so you have 74 more amps you can use for whatever you use. If that is not enough, then you can plan to use 4 6v 220ah run in series parallel to have a big 440 ah battery. That means you can use 220ah safely. You CAN exhaust the batteries past 50%, but if you do you will shorten their life, and it will take significantly larger to charge to full capacity.

I am not an electrician, but I have put a few dozen hours into some research as well as trial/error and have developed a dangerous confidence in the subject. Take my word with a grain of salt, and do the research yourself!
TAOLIK is offline   Reply With Quote
Old 06-25-2017, 09:02 PM   #6
New Member
 
Join Date: Jun 2017
Location: Houston, Texas
Posts: 4
Year: 1994
Chassis: Bluebird
Engine: TC2000
Fair enough. I appreciate all of the advise and resources! We are still shopping but have good prospects and hope to have our bus in the next couple weeks.
I will start measuring my amp hours and voltages and let you know what I find for some final confirmation! ;P


Sent from my iPhone using Tapatalk
earthlingdale is offline   Reply With Quote
Old 06-25-2017, 11:25 PM   #7
Bus Nut
 
Join Date: Mar 2017
Location: Greenwood, Indiana
Posts: 669
Year: 1999
Coachwork: New Flyer
Chassis: D45HF "Viking"
Engine: 11.1L Detroit Diesel S60
Rated Cap: 51,600
A slight correction to TAOLIK's post - when you multiply amps and time you get amp-hours (similarly watts * hours is watt-hours). The reason I say this is because batteries are spec'ed in amp-hours (i.e. how many amps can the battery provide for a certain amount of time). THIS IS A VERY IMPORTANT MEASUREMENT!

So, when running your kill-a-watt and measuring, the kill-a-watt meter will tell you a number of different things. If you simply measure your usage of one appliance over a week, get the energy used measurement in watt-hours. Take that value, divide by 0.8 (this is for an inverter with 80% efficiency), then divide by 12 (i.e. voltage of your battery), and you end up with the equivalent 12V amp-hour battery you need to run that appliance for one week.

Now, do the same for all the other appliances you are considering in your conversion. Add them all up. Finally, multiply by 2 (i.e. you absolutely do not want to drain your battery bank past 50% - read bob for the explanation).

This is the smallest battery bank size you will need to run your appliances for 7 days without any recharging. For many people, 7 days is major overkill. For others who love boondocking without a generator, 7 days without sun is a distinct possibility and must be planned for.

If you are planning on having a generator or consistent access to the grid, a 2-day battery bank is probably the better size (instead of the 7-day size).

If you are planning to weather a zombie-apocalypse, then you may want a 14-day battery bank or larger.

Once you've determined your battery bank size, then you want a minimum solar size of 10% of your battery bank size in amps at full sun (i.e. if you have a 230Ah bank, you want a set of panels that will put out AT LEAST 23 amps in full sun). What you will probably want is a set of panels that will put out enough energy to fulfill nearly your day's usage in 6-8 hours of sun (but that will probably be too expensive).

But read, read, read handy bob solar as what I've said here are rules-of-thumb. Remember - all of this is dependent upon the amount of energy you use. Less energy, smaller battery bank, fewer solar panels, less cost.... More energy, well, you get the idea....

Sent from my SHIELD Tablet K1 using Tapatalk
MarkyDee is offline   Reply With Quote
Old 06-25-2017, 11:45 PM   #8
Bus Nut
 
plfking's Avatar
 
Join Date: Jun 2016
Location: N.C.
Posts: 872
Year: 1997
Coachwork: Bluebird
Engine: DT466E
Rated Cap: 34
Quote:
Originally Posted by TAOLIK View Post
.....and have developed a dangerous confidence in the subject.
__________________
Don

The Busted Flush
plfking is offline   Reply With Quote
Old 06-26-2017, 09:33 AM   #9
Site Team
 
JDOnTheGo's Avatar
 
Join Date: Feb 2017
Location: The West
Posts: 1,001
Year: 1998
Coachwork: MCI
Chassis: 102 EL3
Engine: DD 60
Quote:
Originally Posted by earthlingdale View Post
My question is what type of batteries should I be looking into? And is this sufficient solar to be completely off grid, if say we are using tv and Internet all day?
It is possible - I have been doing it for several years.

Others have provided excellent advice. Those of us that are engineering minded enjoy the research and number crunching but I understand that there are many folks who do not. If you are one of the latter, it is possible to just get 'in' with 'something' and see what happens. This is most certainly NOT ideal (not the shortest nor most cost effective approach). However; I'd prefer to be staying near folks with "some" solar (and learning) than folks that just toss up their hands with "it's too complicated" and then run their construction site generator all day.

For the type of use you've described, 6 volt lead-acid golf cart batteries are an excellent option and are the most inexpensive option.

IMO, having a good battery monitor is very important (Trimetric, Victron, etc. - something with a shunt that is measuring all electrons moving in and out). This will help you care for your batteries (no less than 50% SOC (state of charge)) and learn about what your system is doing (enough solar charging, big draw items, etc...).
__________________
JD - Full timer out west
Missy - 1998 MCI 102-EL3 - 1.7kW Solar - 10kWh Lithium
My Adventures & Build
JDOnTheGo is offline   Reply With Quote
Old 06-26-2017, 11:05 AM   #10
Bus Nut
 
Join Date: Jun 2016
Location: Orange County, CA
Posts: 859
Year: 1990
Coachwork: integral
Chassis: Crown Supercoach II (rear engine)
Engine: Detroit 6V92TAC, DDEC 2, Jake brake, Allison HT740
Rated Cap: 37,400 lbs GVWR
JD makes a good point about having a battery State of Charge monitor, and he mentions the ever-popular monitors that count amp/hours in and amp/hours out, such as the Trimetric and Xantrex. I also have a solar system for my house power, and because I have lots of installed PV power I'm thinking of getting these inexpensive simple Midnite Solar battery capacity meters: https://www.solar-electric.com/midni...ar-mnbcms.html With a correctly-designed solar system you should be fully recharging your batteries every sunny day, so assuming they always reach Float every day I'm thinking that the $50 Midnite Solar meters will be sufficient. Where the other monitors are useful is if you have a system dependent on a generator for charging, then it's more important to know exactly how close your batteries are to needing a recharge.

John
Iceni John is offline   Reply With Quote
Reply

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

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 10:10 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
×