Solar Panel - SailNet Community
 4Likes
  • 1 Post By Mariner62
  • 1 Post By Alex W
  • 1 Post By hydrodog
  • 1 Post By Alex W
 
LinkBack Thread Tools
post #1 of 9 Old 08-17-2013 Thread Starter
Senior Member
 
Magnolia's Avatar
 
Join Date: Dec 2012
Location: Kentucky
Posts: 188
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 3
 
Solar Panel

Hi ya!!

How do I determine what size solar panel we need for an Engel MT35?

Also, would it be smart to buy/install a solar panel that is dedicated only for the Engel, or, install a larger one and then use the power for other uses?

Thnx!!

___________________
1977 Columbia 8.7
Magnolia is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 9 Old 08-17-2013
Junior Member
 
Mariner62's Avatar
 
Join Date: Oct 2012
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Solar Panel

Dont just power the fridge from a panel. Use the panel to charge a battery and power the fridge, and whatever else you want to power, from the battery. That way the fridge will be powered even when the sun is not available.

You'll need to size your panel based on the average current draw of your fridge (and other gear). You'll need to check the specs for the current in amps, and also estimate the cycle on/off of the fridge - this will vary a lot depending on whether the ambient temp is warm or cold.

For example, if your fridge draws 2 Amps and runs for 30 minutes in every hour, that's an average load of 1A. In a 24 hour period that's a total of 24Ah. So you need a panel which can put at least 24Ah into your battery in a day. If you estimate 6 hours of peak solar generation per day, then you need a panel that can produce 4Amps (4 amps x 6 hours = 24Ah)

A typical '12V' panel runs at about 17volts, so that's a requirement for a 68 Watt panel.

If you're powering more gizmos, then you'd need to up the capacity.

You'll need a charge regulator too so the battery doesn't get boiled.

There are many losses in the electronics and unknowns in the insolation effects, so these are all just estimates, and of course it all goes to custard when the sun don't shine :-)

Hope that helps!
blowinstink likes this.
Mariner62 is offline  
Quote Quick Reply Share with Facebook
post #3 of 9 Old 08-17-2013 Thread Starter
Senior Member
 
Magnolia's Avatar
 
Join Date: Dec 2012
Location: Kentucky
Posts: 188
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 3
 
Re: Solar Panel

Hey Mariner62 - thanks for the help!

Ok - I was following until you went from Ah to Volts. LOL Is there a book that tells me that 17volts requires at least a 68 Watt panel?

___________________
1977 Columbia 8.7
Magnolia is offline  
Quote Quick Reply Share with Facebook
post #4 of 9 Old 08-17-2013
no longer reading SailNet
 
Alex W's Avatar
 
Join Date: Oct 2012
Posts: 2,309
Thanks: 2
Thanked 140 Times in 133 Posts
Rep Power: 3
 
Re: Solar Panel

Get a battery monitor first and keep track of your power consumption over an average day. This is a very useful tool to have on the boat anyway and will give you a lot of insight into your battery usage.

Then get a panel large enough to cover that consumption plus 20%.
Magnolia likes this.

I'm no longer participating on SailNet.
Alex W is offline  
Quote Quick Reply Share with Facebook
post #5 of 9 Old 08-18-2013
Junior Member
 
Mariner62's Avatar
 
Join Date: Oct 2012
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Solar Panel

Power is volts x amps. So 17 x 4 = 68.

Couldn't agree more about the battery monitor. I have a BMV-600, but there are many others available. Absolutely invaluable.
Mariner62 is offline  
Quote Quick Reply Share with Facebook
post #6 of 9 Old 08-18-2013 Thread Starter
Senior Member
 
Magnolia's Avatar
 
Join Date: Dec 2012
Location: Kentucky
Posts: 188
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 3
 
Re: Solar Panel

Thank you, Alex W and Mariner62 - we will get a battery monitor. Currently we have two batteries. Fairly new. I need to write down what they are. But...will one monitor work for both?

Mariner - thanks for spelling out the math equation for me. I'll write it down so I can remember is. LOL

___________________
1977 Columbia 8.7
Magnolia is offline  
Quote Quick Reply Share with Facebook
post #7 of 9 Old 08-18-2013
Junior Member
 
Join Date: Jun 2013
Location: NH/Montserrat/afloat
Posts: 20
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 0
 
Re: Solar Panel

Practically speaking you want as many panels as you have space for .... you can use all the power that you have then some.... most everyone even with panels needs to recharge their batteries just not so often.
Good Cheap panels can be had from Sun Electronic out of Miami....
Magnolia likes this.
hydrodog is offline  
Quote Quick Reply Share with Facebook
post #8 of 9 Old 08-18-2013
no longer reading SailNet
 
Alex W's Avatar
 
Join Date: Oct 2012
Posts: 2,309
Thanks: 2
Thanked 140 Times in 133 Posts
Rep Power: 3
 
Re: Solar Panel

The battery monitor will work for two batteries that are tied in parallel, but it won't work for two batteries on different sides of a battery switch (where one is used for the house battery, and one is used for the starter).

If you only buy one monitor you want it on the house battery.
Magnolia likes this.

I'm no longer participating on SailNet.
Alex W is offline  
Quote Quick Reply Share with Facebook
post #9 of 9 Old 08-19-2013 Thread Starter
Senior Member
 
Magnolia's Avatar
 
Join Date: Dec 2012
Location: Kentucky
Posts: 188
Thanks: 0
Thanked 2 Times in 2 Posts
Rep Power: 3
 
Re: Solar Panel

Thanks again everyone for your help. It is greatly appreciated.

___________________
1977 Columbia 8.7
Magnolia is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
solar panel MarkusM Gear & Maintenance 7 02-17-2013 12:41 AM
How much solar panel(s)? F15EWSO Electrical Systems 14 08-14-2012 11:10 PM
B32 & Solar Panel Dcneuro Bristol 2 07-26-2007 10:56 AM
solar panel maestro Gear & Maintenance 3 11-20-2002 11:02 AM
Solar panel ldbarker Gear & Maintenance 3 10-27-2002 01:31 PM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome