RV solar

[xxiiiliv]

Ya know, for having built buildings for 40 years, I realize it’s the stuff like this that squeezed by me. So let me see if I got this right... I have 81 ah @ 12v. That’s 972 watts. So, if the fridge consumes 11 watts, I can power it for 88 hours?

 

[Mikeee54]

There are a bunch of variables that need to be considered here is a link to a calculator that may be helpful. They also have very good articles which explain the details behind each variable. Hope this helps.
https://www.altestore.com/store/calculators/off_grid_calculator/

 

[MAC702]

...So let me see if I got this right... I have 81 ah @ 12v. That’s 972 watts. So, if the fridge consumes 11 watts, I can power it for 88 hours?

Again, you've got to keep the units straight to avoid later confusion.

81 A-hours x 12 V = 972 W-hours, not just watts.

Then, yes:

972 W-hours / 11 W = 88 hours.

Minus all efficiency and less-than-ideal production losses, of course.

What's the start-up power on the fridge?

 

[xxiiiliv]

Again, you've got to keep the units straight to avoid later confusion.

81 A-hours x 12 V = 972 W-hours, not just watts.

Then, yes:

972 W-hours / 11 W = 88 hours.

Minus all efficiency and less-than-ideal production losses, of course.

What's the start-up power on the fridge?

I’m going to put a meter on the cord today and check what everything draws. The boss says she needs a/c and coffee at minimum, so maybe I’m getting into generator country

 

[MAC702]

What are you calling a "fridge?" Is it using electricity (11 watts?) just for controls? A typical RV refrigerator, running on electricity for cooling will be in the 180 watts ballpark. And then it might need 600 watts to start the compressor.

 

[xxiiiliv]

What are you calling a "fridge?" Is it using electricity (11 watts?) just for controls? A typical RV refrigerator, running on electricity for cooling will be in the 180 watts ballpark. And then it might need 600 watts to start the compressor.

 

[MAC702]

Okay, so when you are on 12 VDC supply, the cooling is provided by the propane.

 

[Mikeee54]

I believe that model is a 3way 120/lp/12v typically propane is not used in 12v mode on 3way models.

 

[xxiiiliv]

Okay, so when you are on 12 VDC supply, the cooling is provided by the propane.

That is correct

 

[Bumper]

And if you put in a large inverter/battery charger, so you can have 110 VAC without running the generator, then the fridge will pull about 30 amps from the battery bank while it is cycled on. Running the microwave, in the same manner, pulls an astonishing 170 amps!! I run the fridge on AC when driving, as it's one less potential ignition source in case of an accident (the absorption fridge has an open propane flame).

 

[SixshooterSam]

I believe that model is a 3way 120/lp/12v typically propane is not used in 12v mode on 3way models.

Well you aren't cooling anything using only 11 watts if that electricity is the only energy source, that's for sure.

 

[xxiiiliv]

Well you aren't cooling anything using only 11 watts if that electricity is the only energy source, that's for sure.

How do you figure

 

[SixshooterSam]

How do you figure

Because 11 watts worth of electricity won't power any A/C or refrigerant compressor of any kind on the planet.

 

[xxiiiliv]

Because 11 watts worth of electricity won't power any A/C or refrigerant compressor of any kind on the planet.

Fair enough

 

[awopahoe]

Your confusing watts with amp-hours, 2 totally different subjects! Batteries use amp-hours for power, not watts. Start readin and learn something! Good Luck https://www.mobile-solarpower.com/

 

[xxiiiliv]

Your confusing watts with amp-hours, 2 totally different subjects! Batteries use amp-hours for power, not watts. Start readin and learn something! Good Luck https://www.mobile-solarpower.com/

Nicely stated. You must be a teacher

 

[awopahoe]

Nicely stated. You must be a teacher

No, I just do all of my own homework and not rely on the dummies on the web that think they know-it-all and tell you useless crap you don't need, because they're the one's that don't have a clue!

 

[xxiiiliv]

“Dummies on the web”. I like that.

 

[MAC702]

Says the guy that linked to a website selling complicated systems to DIYers with "no experience required."

 

[xxiiiliv]

... and how do I know these guys aren’t those “dummies on the web” as well