solar

[kellymegtug]

I have a solar system with 320 watts and 2000 watt inverter.
Thought I could run all weekend with refrigerator on auto and residential fan...Not the case. Does a refrigerator use a lot of watts, should I keep it on propane?

[kellymegtug]

Fan not van 🙂
smart mode recharging...have to look that up

[kellymegtug]

I have 4 6 volt batteries and got a fantastic van. I leave the refrig on propane. thanks for the replies

[RoyB]

I think you have to look at the whole system to get to where you want to be when camping off the power grid.

Solar Panels only produce energy when they are in high sun which is probably a good 6 hours or so for the most of us. The solar panels do not produce alot of DC Current when in the high sun with a typical 120WATT SOLAR PANEL only generating around 5-6 AMPS of DC current during the typical 6 hour high sun cycle. If you plans was to run directly off the solar panel for this period of time then all you can expect is have you only drawing around 5-6 AMPS of DC current.

With this in mind the thing one wants to do now is to have a very good battery system setup and let the SOLAR PANELS to their thing to keep the battery bank charged up. To run your 120VAC appliances from the battery bank you will need an INVERTER installed. To fully operate a 2000WATT Inverter it will draw around 162AMPS of DC current minus efficiency. Keep in mind what ever you take out of the battery you must put back in. It would be very hard to refill any of this battery drain just having a 120WATT Solar Panel which only produces 5-6 AMPS of DC current. Your 320WATT Solar bank will most likely only produce 12-13 AMPS DC current top put back into your batteries.

Having a larger battery bank will extend your on-air time but as you can see from all of this even that will have a short term battery capacity. You need to find out what long your battery bank will produce the amount of current you want to use and do accordingly with what you have turned on or increase the battery bank to the level of DC current you want to produce.

In my case my battery has to be big enough to get me through one day/night run as where I camp here on the East side of the USA I have generator run time restrictions to deal with so I have to be able to make it 8AM the next morning with my battery bank setup and not be below 50% battery capacity. At 8AM I am usually allowed to start running my generator. Using smart mode charging it will take me a good three hours time using the generator to get my battery back up to its 90% charge state where I can start using them again for the day/night load.

For me this is where solar panels will really help me out. After I run my generator for around one hour I will be over the very high current demand as they start taking when on charge. I initially see 52-53 amps when I first hit my 50% depleted battery bank with 14.4VDC and this starts slowly dropping down as the batteries take on charge. When this current level gets down to around 15AMPs or so I can switch to solar panels and continue my re-charge effort without running the generator while the solar panels are in high sun.

At the end of the high sun period I should be very much ready with my battery bank to make my day/night run off of the batteries until 8AM the next morning.


Just going though this routine to relay on what it takes for me to be able to run all night with my battery bank. You may have to experience the same routine to get to the point you want to be at.

It does take planning. You can't run to the woods with some solar panels and an inverter and expect it all to work... This was my case at any rate...

I became very successful over the past few years just running my things off the batteries and recharging my battery bank system with using my 2KW generator. Now I can add solar panels up to around the 320-360 WATT capacity level and really help out my daily routine of getting the batteries recharged and ready for the next night run off the batteries.

Since you already have the solar panels and Inverter in place I think your next step is to beef up your battery banks and smart mode recharging effort to make it all work for you successfully every time you head out.

Just some of my thoughts here - everyone has their own plan of attack...

Roy ken

[lillyputz]

Depends on how many batter amps you have available. as a rule of thumb, one solar watt per one batt amp. also the number of hours during the day the sun is on your panels.

Lullyputz

[laknox]

kellymegtug wrote:
I have a solar system with 320 watts and 2000 watt inverter.
Thought I could run all weekend with refrigerator on auto and residential fan...Not the case. Does a refrigerator use a lot of watts, should I keep it on propane?

Nobody mentioned that the fan is probably using more power than the fridge; they're notoriously inefficient. Read how many people kill their batteries by running the furnace just a few hours at night.

Lyle

[reed_cundiff]

We run the Dometic on solar during the day. If we know that it will be full solar insolation on the next day, we sometimes leave it on AC at night and wake up about -3000 W-hours. But as KD4UPL noted above, propane is so efficient that using the solar is more of a life-style statement than anything else. We have 1.42 kW of solar and 9.6 kW-hours of LFP. We have run A/C for 3.5 hours several times and generally turn it on for half an hour at the end of a hot day's travel.

Pianatuna and Sushidog have provided me with very useful information
Reed and Elaine Cundiff

[KD4UPL]

Run the fridge on propane. It will probably run for a month or more on one 20 lb. tank.

[bigmurf]

How many batteries do you have?

[sushidog]

Your typical, modern 18cf home refrigerator uses about 41 KWH/month or 1.37 KWH/day - a much more efficient use of A/C power than an RV absorption fridge.

https://www.efficiencyvermont.com/For-My-Home/ways-to-save-and-rebates/Appliances/Refrigerators/General-Info/Electric-Usage-Chart

However my RV fridge will run over a month on a tank of propane. Your mileage may vary.

Chip

[pianotuna]

Hi,

The dometic fridge in my rv uses 4.8 kwh per day. Generally they run on a 2:3 duty cycle (i.e. 40 minutes of on time per hour).

[time2roll]

Yes keep the fridge on propane. Same with the water heater.

[mrkoje]

A quick Google search reveals that the Norcold fridges like mine (10cf) use around 325-400 watts. Add in the parasitic losses and you are using more power then you are replacing with a 320 watt solar setup. Take the fridge off AC from the inverter and use the propane. If you do that you should be set for some nice power filled boondocking time!

I've recently purchased the 120w GoPower portable unit to start with and it charges the batteries up pretty well. I'm going to eventually get the GoPower flex panels and rig up a 300+ watt setup on top the trailer. I still need to install an inverter - just not sure how I want to do it.

Good luck to you!