Portable Solar Panel - Off Grid

Brenintot

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My Danbury Go Ford Transit Custom Campervan has a Compressor fridge & 100a AGM 2nd battery fitted from new. I worked out that it should run for 20 hours ‘Off grid’. I've just purchased a 60w Portable Solar panel & controller that produces max 3.6a . So could possibly keep the fridge going for another 12h to cover me for 2 nights. It’s important for me to keep my medication stored at the correct temperature. Have I got it right? ‘
 
Brenintot said:
My Danbury Go Ford Transit Custom Campervan has a Compressor fridge & 100a AGM 2nd battery fitted from new. I worked out that it should run for 20 hours ‘Off grid’. I've just purchased a 60w Portable Solar panel & controller that produces max 3.6a . So could possibly keep the fridge going for another 12h to cover me for 2 nights. It’s important for me to keep my medication stored at the correct temperature. Have I got it right? ‘
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I would work on the basis of a compressor fridge averaging at around 2Ah/Hr in real life (as opposed to optimal manufacturers test conditions). So about 40Ah in 20 hours. Assuming you don't want to go below 50% State of Discharge, your maths for the first bit is good :). But you are not leaving yourself very much leeway to use the battery power for anything else mind?

I don't think your Solar panel will do what you are hoping it will. Too small with too little sun will make too little difference. It will help, but not as much as you want. What you really need is a second battery, especially if the fridge is "mission critical" to your camping.
 
This time of year you will be very lucky to get 1A out of a 60w panel. Don't know where they get their figures from. You will put more juice in the battery just driving around for 30 minutes. If the fridge is important change to Lithium which will give you far more usable Amps. 2 x 120Ah lithium should run a fridge for 100 hours at 2A.
 
My 200w solar and 2 90ah lead acids can run my fridge no bother at this time of year, and always full charge by about midday.
My we fridge is 250mA an hr, but does not switch on much in cold weather, summer lots of sun even though it has to work much harder.
 
The output from solar depends on time of year (hours of sun light and angle of sun) and latitude (again angle of sun).
The table below shows the ah you can expect from a 150w unit on a typical day.
Your 60w unit will provide about 1/3rd of this eg. 10 ah in Aberdeen in March.

BTW when you say "100a AGM 2nd battery" do you mean "100ah AGM 2nd battery" . And is this a 2nd leisure battery or is it your only battery besides the starter (vehicle) battery?
solaroutput.jpg
 
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r4dent said:
The output from solar depends on time of year (hours of sun light and angle of sun) and latitude (again angle of sun).
The table below shows the ah you can expect from a 150w unit on a typical day.
Your 60w unit will provide about 1/3rd of this eg. 10 ah in Aberdeen in March.

BTW when you say "100a AGM 2nd battery" do you mean "100ah AGM 2nd battery" . And is this a 2nd leisure battery or is it your only battery besides the starter (vehicle) battery?
View attachment 118885
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Thanks for your reply to my post, yes it's the 2nd battery, there's a 240v 20amp charger installed & a split charger fitted for when van is being driven.
 
wildebus said:
I would work on the basis of a compressor fridge averaging at around 2Ah/Hr in real life (as opposed to optimal manufacturers test conditions). So about 40Ah in 20 hours. Assuming you don't want to go below 50% State of Discharge, your maths for the first bit is good :). But you are not leaving yourself very much leeway to use the battery power for anything else mind?

I don't think your Solar panel will do what you are hoping it will. Too small with too little sun will make too little difference. It will help, but not as much as you want. What you really need is a second battery, especially if the fridge is "mission critical" to your camping.
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Thanks, the fridge runs off the 2nd 100 a/h battery & there's a couple of LED strip lights & a small on demand water pump. I went for a portable panel so I can position it to obtain the best of the sun's energy.
 
r4dent said:
The output from solar depends on time of year (hours of sun light and angle of sun) and latitude (again angle of sun).
The table below shows the ah you can expect from a 150w unit on a typical day.
Your 60w unit will provide about 1/3rd of this eg. 10 ah in Aberdeen in March.

BTW when you say "100a AGM 2nd battery" do you mean "100ah AGM 2nd battery" . And is this a 2nd leisure battery or is it your only battery besides the starter (vehicle) battery?
View attachment 118885
Click to expand...
No way will you get 10Ah from a 60w solar panel its not possible. 10Ah is 10A per hour. What they are saying is 10 amps per day if you are lucky. The other problem with the table is they don't tell you the voltage from the panel or if the stated voltage is from a Solar Controller.
 
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QFour said:
No way will you get 10Ah from a 60w solar panel its not possible. 10Ah is 10A per hour. What they are saying is 10 amps per day if you are lucky.
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Sorry you are wrong

QFour said:
10Ah is 10A per hour.
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Wrong wrong wrong
10ah is 10 amps for 1 hour,

but it is also 1 amp for 10 hours; 0.5 amps for 20 hours; 2.5 amps for 4 hours etc etc.

Multiply current (amps) by time (hours) to give energy produced (amp hours).
 
Brenintot said:
My Danbury Go Ford Transit Custom Campervan has a Compressor fridge & 100a AGM 2nd battery fitted from new. I worked out that it should run for 20 hours ‘Off grid’. I've just purchased a 60w Portable Solar panel & controller that produces max 3.6a . So could possibly keep the fridge going for another 12h to cover me for 2 nights. It’s important for me to keep my medication stored at the correct temperature. Have I got it right? ‘
Click to expand...
I also have a compressor fridge and 150w sola panel . As lead acid batterys will only safely discharge to 50% I have replaced my 3 lead acid 100w batteries with two 100w lifpo batteries and find that I can manage off grid for for several days, mainly because Lifpo batteries can be rechareged faster and discharge safely to a lower level without damage.
 
r4dent said:
Sorry you are wrong


Wrong wrong wrong
10ah is 10 amps for 1 hour,

but it is also 1 amp for 10 hours; 0.5 amps for 20 hours; 2.5 amps for 4 hours etc etc.

Multiply current (amps) by time (hours) to give energy produced (amp hours).
Click to expand...

No need to shout. So can you explain line 2 - Liverpool - January - 10 Ah per day . It doesn't really make a lot of sense. You certainly won't get 10A for 1 hour or even 1A for 10 hours .
 
QFour said:
No need to shout. So can you explain line 2 - Liverpool - January - 10 Ah per day . It doesn't really make a lot of sense. You certainly won't get 10A for 1 hour or even 1A for 10 hour.
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Sorry if you were offended by my use of font. I used bold and larger font to denote the subtle difference between what you stated and what I believe to be accurate.
I thought that using upper case was shouting,

I produced that table for my own use and I have published it several times in the group without anyone providing alternative figures.
It look a lot of research and calculation to produce.
You are free to use or ignore it as you choose.
So we can see if we are in the same ball park - What is your estimate for a horizontally mounted 150 w solar in Liverpool in January?.
 
Your table would be better if it was written in watts. You would then be able to see how many watts were generated in a day. A 120A battery is 1440 watts.
 
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