Solar Fridge

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Glenn-BJ74

Glenn-BJ74

10 Year 15 Year
Joined
May 7, 2006
Threads
279
Messages
3,363
Location
Kelowna, BC
As part of my Utah trip preparations I just finished installing two solar panels to power my ARB fridge and keep my batteries fully charged.
The objective was to be able to power the fridge and maintain full battery charge on an indefinite basis -- without running the truck ( avoids smoking up the campsite) or using external power sources generators or shore power).

The third battery is a more popular option, but it still needs to be charged, weighs 55 lbs and takes up space. The dedicated battery option is initially cheaper, but you must factor in battery replacement every 3-4 years. The panels will last 20 years+ and the panel/ controller will have separate resale value..

Set-Up

Fridge - old style ARB fridge on 24 vdc (2.7 amp @ 12 vdc, when operating)
Batteries – two generic (Korean) marine starting batteries (2x105 amp-hrs)
Solar Panels – two 40 watt panes monocrystalline (in series for 24 volt) 24.5" x 21.5" x 1" (mounted across the top within the roof rack)
Charge Controller: Morningstar SunSaver MMPT (12/24 vdc).
Weight: 20 lbs with all hardware (panels are 8.5 lbs each).

More information to come -

P1030221 (Medium).webp
 
That is very cool! Is that a bit of boat cable I see there peeking out between the arrays? I've installed quite a few systems on cruising boats, very useful, and lowers duty cycle on generators etc..
 
The panels look great. Will you still be able to stack stuff on top of them, when you have to?
 
Even the small shadow cast by the load bars would significantly degrade efficiency?
 
My main concern would be with branch damage to the panels. I am still planning on getting a solar set-up for my CPAP machine. I'll have to ask Trevor (Pap Solar) about what he thinks of mounting it under the roof rack. He told me the best camp mount is on a swivel so you can track the sun while you are camped. But that is mainly for people who park their trailers in one spot for extended periods. It would be nice to have the best of both worlds: flat for highway driving andf swivel mount for sun tracking.
 
sailor said:
That is very cool! Is that a bit of boat cable I see there peeking out between the arrays? I've installed quite a few systems on cruising boats, very useful, and lowers duty cycle on generators etc..
Click to expand...

Sailor you have 'sharp eyes' - yes I only use tinned copper boat cable on my truck - for this project 16 gauge 2 conductor - white sheathed.
 
LanceCruiser said:
The panels look great. Will you still be able to stack stuff on top of them, when you have to?
Click to expand...


  • With the panels on top -- I have still 4' x 5' feet (20 sq.feet) of storage - way more than I need now.
  • As for branch protection, when I get back I will look into some plastic or Lexan.
  • Mounting underneath would have been very difficult and reduces output. - offers limited branch protection
  • I can still put a boat on top because my front has a raised spoiler.
  • Solar panels are rated for hail events so they are fairly tough.

    Tilting these things to track the sun would be an enginneering feat requiring tilting and swiveling, while allowing them to be secured flat for road travel - an excessive investment in time and money for a "one-off" for me. Given the pounding my rig takes the installtion has to be very tough and simple.
    Rather I went 30% over-size ( 60 watt is the basic) and the MPPT charge controller and the monocrystalline panels - both are more efficient than the standard technogy. The cheaper charge controllers can only use the current when delivered between 10 vdc and 15 vdc - the MPPT technolgy can use the current deliverd from the panels above 15 volts. The charge contoller has 4 stage charging - bulk, absorption, float and equalization - the charge controller must be told what kind of battery it is charging - AGM, gel, sealed or flooded.
 
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Glenn,

Would you mind posting sources for your equipment? I am interested in a setup like this.

Also, in my research, the 'charge controller' is designed to prevent over charging of the battery but also draining of the battery when connected to the solar panel. In your research, did you come across anything that describes how a solar panel can 'drain' a battery? (or did I read this wrong? Is it referring to the 'load' on a battery can be prevented from over-draining a battery past it's lower voltage limit). I.E. if a battery is connected to a solar panel with no load on the battery overnight, will the battery experience a 'drain'? I found this odd, so I just wanted to be sure.
 
I think most charge controllers have back drain protection. The SunSaver Charge controller has battery drain protection in addtion to other fault protection features. It has 12v/24 volt capability ( up to 75 v) and a small mounting footprint as others charge controllers are designed to be mounted on a wall and so are too big for my small cab.

I need to field test everyting in Utah and I can report back.
 

Attachments

Glenn-BJ74 said:

  • Tilting these things to track the sun would be an enginneering feat requiring tilting and swiveling, while allowing them to be secured flat for road travel - an excessive investment in time and money for a "one-off" for me. Given the pounding my rig takes the installtion has to be very tough and simple.
Click to expand...
I only have the one panel so far, and have it "portable". I just position it somewhere in the sun and plug it in. It has a fairly long extension line.


AJAEbj42 said:
Glenn,

Would you mind posting sources for your equipment? I am interested in a setup like this.
Click to expand...

A local supplier is in Burnaby, up near ATEB. He doesn;t have the fancy controllers Glenn has, but the panels look to be about the same.
For info, see https://forum.ih8mud.com/ca-bc-coastal-cruisers/495325-solar-power.html

P1030225.webp
 
Enigma said:
A local supplier is in Burnaby, up near ATEB. He doesn;t have the fancy controllers Glenn has, but the panels look to be about the same.
For info, see https://forum.ih8mud.com/ca-bc-coastal-cruisers/495325-solar-power.html
Click to expand...

I think you will find that Trevor has the fancy stuff now. If he doesn't have it in stock, he can get exactly what you want. What I liked about him is he actually listens to what you need it for and then recommends. He lists stuff on CL but mainly sells by word of mouth.
 
Enigma said:
[/LIST]
I only have the one panel so far, and have it "portable". I just position it somewhere in the sun and plug it in. It has a fairly long extension line.




A local supplier is in Burnaby, up near ATEB. He doesn;t have the fancy controllers Glenn has, but the panels look to be about the same.
For info, see https://forum.ih8mud.com/ca-bc-coastal-cruisers/495325-solar-power.html
Click to expand...

That works for picnics - but on 2 week bush trip I do not want to haul a solar panel out each day hook it up and adjust it every hour (watch it fall over periodically when the wind blows - watch in horror as someone (Bill) backs over it) :hillbilly: and then pack it and stow it securely each time - too busy with other things ..................


I got my equipment out of the US.The two charge controller types are Pulse Width Modulation. (PWM) standard type and Maximum Power Point Tracking ( MPPT). Their are Chinese MPPT charge controllers selling cheap ( e.g. Wellsee) - but independent testing concluded they are junk
 
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Glenn-BJ74 said:
That works for picnics
Click to expand...

Ha Ha, too funny. I can just picture Jeff having a picnic at the mall telling his old lady to rotate the solar panel while she gets up to go get some grey pupon for the sandwich he is making!:hillbilly:

(I said picnic at the mall because Jeff drives an 80, incase someone is wondering why Jeff and family would be having a picnic there! :flipoff2:)
 
Glenn-BJ74 said:
That works for picnics - but on 2 week bush trip I do not want to haul a solar panel out each day hook it up and adjust it every hour (watch it fall over periodically when the wind blows - watch in horror as someone (Bill) backs over it) :hillbilly: and then pack it and stow it securely each time - too busy with other things ..................
Click to expand...

True enough. I plan to do something similar to yours, once I have a real roof rack.

Deny said:
Ha Ha, too funny. I can just picture Jeff having a picnic at the mall telling his old lady to rotate the solar panel while she gets up to go get some grey pupon for the sandwich he is making!:hillbilly:
Click to expand...


For the record, I do not like mustard.
 
Grey pupon :D too funny

On topic, I had no idea a 74 set up with camping bells and whistles kills batteries in 3-4 years - ouch. Reminds me I should be proactive about replacing the 10+ yr old battery in the 40 soon.

The solar array is a nice tidy fit on the roof rack. Do they mind vibration?
 
I am in Boise, ID waiting for Greg in Carbelas- my solar panels are putting out 60 watts !!!!!
 
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