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pjstock
Samba Member
Joined: November 07, 2017
Posts: 118
Location: toronto, Ontario
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 Posted: Thu Aug 02, 2018 12:41 pm Post subject: Solar setup to charge Aux Battery to run electric fridge? |
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The Samba / eurovans might not be the place to get help on electrical questions for a 220v European T4 California, but I'll throw this out there....
Mine is a 1995 T4 transporter California imported from Europe and so the power system is all 220v (220v to the Aux Battery charger which outputs 12v to the Aux Battery).
I'm currently on our inaugural road trip andy only real frustration has been that the Aux Battery drains (I can't use shore power overnight A) as it is often not available and B) I need a special patch cable to adapt the NA plugs and leads) and the fridge dies (this Domestic fridge is 12v 60W not gas powered).
I got to thinking about solar panels today. How would I figure out what scale setup I would need to best charge this Aux Battery
Last edited by pjstock on Fri Aug 03, 2018 11:08 am; edited 1 time in total |
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Broseph Stalin
Samba Member
Joined: March 28, 2018
Posts: 433
Location: Colorado
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| Posted: Thu Aug 02, 2018 4:25 pm Post subject: Re: Solar setup to charge Aux Battery to run electronic fridge? |
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| pjstock wrote: |
The Samba / eurovans might not be the place to get help on electrical questions for a 220v European T4 California, but I'll throw this out there....
Mine is a 1995 T4 transporter California imported from Europe and so the power system is all 220v (220v to the Aux Battery charger which outputs 12v to the Aux Battery).
I'm currently on our inaugural road trip andy only real frustration has been that the Aux Battery drains (I can't use shore power overnight A) as it is often not available and B) I need a special patch cable to adapt the NA plugs and leads) and the fridge dies (this Domestic fridge is 12v 60W not gas powered).
I got to thinking about solar panels today. How would I figure out what scale setup I would need to best charge this Aux Battery |
If you can get a portable 100w 12v solar panel with controller you should be able to clip it directly onto the battery + and - terminals.
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'67 Riviera poptop conversion in the US, 1984-1990
'95 EVC Winnie, 2018, Sold
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Abscate
Samba Member
Joined: October 05, 2014
Posts: 22665
Location: NYC/Upstate/ROW
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| Posted: Fri Aug 03, 2018 3:00 am Post subject: Re: Solar setup to charge Aux Battery to run electronic fridge? |
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| pjstock wrote: |
The Samba / eurovans might not be the place to get help on electrical questions for a 220v European T4 California, but I'll throw this out there....
Mine is a 1995 T4 transporter California imported from Europe and so the power system is all 220v (220v to the Aux Battery charger which outputs 12v to the Aux Battery).
I'm currently on our inaugural road trip andy only real frustration has been that the Aux Battery drains (I can't use shore power overnight A) as it is often not available and B) I need a special patch cable to adapt the NA plugs and leads) and the fridge dies (this Domestic fridge is 12v 60W not gas powered).
I got to thinking about solar panels today. How would I figure out what scale setup I would need to best charge this Aux Battery |
You will need roughly the same amp hours per day as the temperature in Celsius, with apologies to engineers for a units problem
So if it’s 82 F, thats 28C, and you need 28 amp hours per day to cool
That’s 330 watt hours. You will need a big solar panel to keep charged
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pjstock
Samba Member
Joined: November 07, 2017
Posts: 118
Location: toronto, Ontario
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| Posted: Fri Aug 03, 2018 3:57 pm Post subject: Re: Solar setup to charge Aux Battery to run electric fridge? |
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| I am an electricity ignoramus but if my fridge needs 60w (so I would guess 60whours per hour?) Why would I need 330wh to run it? |
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evinor
Samba Member
Joined: December 01, 2016
Posts: 34
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| Posted: Sat Aug 04, 2018 11:36 am Post subject: Re: Solar setup to charge Aux Battery to run electric fridge? |
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I'm no expert, but I think it's that if you need to produce 28 amp hours, you figure out the power you need in watts by multiplying the 28 amp hours by your voltage (12), so 28 x 12 = 336 watts.
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Abscate
Samba Member
Joined: October 05, 2014
Posts: 22665
Location: NYC/Upstate/ROW
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| Posted: Sat Aug 04, 2018 1:40 pm Post subject: Re: Solar setup to charge Aux Battery to run electric fridge? |
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| pjstock wrote: |
| I am an electricity ignoramus but if my fridge needs 60w (so I would guess 60whours per hour?) Why would I need 330wh to run it? |
It uses 60 watts, or 60 Joules per second, anytime it is on and the cooling unit s functioning. With the cooling unit off, it will hardly pull anything.
60 watts x 24 hours is 1400 Watt hours per day
It turns out your fridge doesn't use the 60 Watts all the time, only when it is running, so the actual usage will be some fraction of that - somewhere between 1/6- 1/4 depending on how often it is opened, how cold it is set, ambient temperature.
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pjstock
Samba Member
Joined: November 07, 2017
Posts: 118
Location: toronto, Ontario
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| Posted: Sun Aug 05, 2018 4:11 am Post subject: Re: Solar setup to charge Aux Battery to run electric fridge? |
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So do you still figure I need an approx 330watt solar system?
For a 60wfridge drawing power 1/4 the time.ir is On? |
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Abscate
Samba Member
Joined: October 05, 2014
Posts: 22665
Location: NYC/Upstate/ROW
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| Posted: Sun Aug 05, 2018 5:19 pm Post subject: Re: Solar setup to charge Aux Battery to run electric fridge? |
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The duty Cycle is the big unknown, because it depends on
Ambient temperature in Bus
Solar load
How often it is opened
Battery voltage
Temperature setting
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So do you still figure I need an approx 330watt solar system?
For a 60wfridge drawing power 1/4 the time.ir is On? |
330 watt hours is what you need to replace
So if you charge for a 6 hour day, you need about a 50 watt solar output. To attain this, you need a panel rated at 200 watts....half the loss being cosine law and the other half being dirt , shade, bird droppings, tears of Split owners.
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Broseph Stalin
Samba Member
Joined: March 28, 2018
Posts: 433
Location: Colorado
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| Posted: Mon Aug 06, 2018 3:36 pm Post subject: Re: Solar setup to charge Aux Battery to run electric fridge? |
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Maybe call this outfit https://www.solar-electric.com/marine-rv.html
800 383-0195
Or Renogy - 800 330-8678
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'68 Bus in West Germany, 1977-1979
'67 Riviera poptop conversion in the US, 1984-1990
'95 EVC Winnie, 2018, Sold
'03 EVC Winnie, 2018, Sold |
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