Solar power dropping

[AppleTini]

This is our first weekend using our 2021 Geo Pro. It has the 190 watt solar panel. We upgraded to a single lithium battery Dakota 12v 100 Ah. We are running the fridge only. In the first 24 hours we had 100% battery showing on the monitor except when we turned the fan on in the bathroom it dropped to low 90s. Yesterday afternoon we ran the inverter for about an hour to charge devises. Inverter was shut off afterwards. The power built up to low 90s before night time. This morning we woke up and the power was at 60 percent and it has dropped to 20% in 3 hours. It seems like something is draining the power. We have same weather conditions as yesterday when it was steady at high 90-100 all day until the inverter was on.
Any ideas? Is it not possible to run the fridge on solar panel? If so why would we be good the first 24 hours ?

[glen1971]

Is your fridge on 12 volt or propane?

[AppleTini]

Yes 12 volt. No propane option.

[boondocking]

Originally Posted by AppleTini

This is our first weekend using our 2021 Geo Pro. It has the 190 watt solar panel. We upgraded to a single lithium battery Dakota 12v 100 Ah. We are running the fridge only. In the first 24 hours we had 100% battery showing on the monitor except when we turned the fan on in the bathroom it dropped to low 90s. Yesterday afternoon we ran the inverter for about an hour to charge devises. Inverter was shut off afterwards. The power built up to low 90s before night time. This morning we woke up and the power was at 60 percent and it has dropped to 20% in 3 hours. It seems like something is draining the power. We have same weather conditions as yesterday when it was steady at high 90-100 all day until the inverter was on.
Any ideas? Is it not possible to run the fridge on solar panel? If so why would we be good the first 24 hours ?

Yes, it is possible with about 400 watts of solar and 200 AH of battery.

[AppleTini]

Ok thanks for the reply. When it worked so good the first day I questioned what had changed so thought maybe I did something.

[boondocking]

No. you didn't do anything wrong.
Your fridge will use about 6 amps when running. Your solar panel will produce about 8-9 amps in full sun.
The fridge running at 50% duty cycle will use about 70 AH in a 24 hour period. The solar panel will generate about 60 AH per day with full sun.
Factoring in parasitic draw from CO detector, propane detector, entertainment center standby etc. the battery will never get a full charge. Each day that goes by there will be even less of a full charge.

[NJKris]

Try to use USB ports for charging. The inverter is inefficient for very light loads, and 86% efficiency is best you can hope for with heavier loading. But 12v fridge is what's killing you. Can't believe they are putting these in GeoPros.

[AppleTini]

Thanks for breaking down the numbers. That makes sense now.
Also, I just noticed the USB port on the panel When I was fooling around with all this. I didn’t realize you can plug in to that and it by passes the need to turn on the inverter. Sounds obvious now but I didn’t think of it so glad you mentioned it

[NJKris]

My GeoPro 19FD also has USB near outlet on nightstand. You should put your model in your signature.

[tomkatb]

Inverters on standby will consume 1-2 amps per hour. So keep it off as much as possible. They should be installed with a remote on off switch so it is easy.

On their best days 100 watt solar panels produce about dc 25 amps. Trees and clouds are the enemy. The angle of the panel to the sun matters,

You should use near 100 amps total per day with an electric fridge. Good practice with the fridge is important. Got to be the electricity czar. Day to day apparent changes are often operator errors. Kid left the inverter on after charging his phone!

Best to have 6-800 watts of solar and 200 amps of battery. Need double everyday needs for clouds. Unless you always play in the west.

In rv’s batteries are the weak link.

[AppleTini]

Thanks for all the info. Greatly appreciated.
This is now leading to another question. How do I disconnect the 12 volt fridge from using solar power. I have the manual and it says turning the temperature control down to zero stops the cooling cycle but does not shut off the power to the unit. I tried to look on line but don’t see anything. Would I have to worry about the power draw if I just leave it zero. This doesn’t seem right to me I think there should be a way to disconnect totally. I can try calling the dealer if this is a situation specific to our rig.
Also, one more thing. Originally we thought if the solar was not adequate we would look at adding one of those solar on the side units. Go Power advertises one for 200 watts. The sticker on the side of our camper says it’s rated for 20 amps so I think that would work? They are expensive so do not want to experiment without knowing for sure. That would give us 390 watts but still one battery. When we switched to the lithium battery we thought that would be like having two batteries. You think we would still need a second lithium then? Or would we be close to making it depending on weather? The front battery compartment wouldn’t fit a second lithium. Just double checking before we leave this idea of having the fridge work dead in the water.

[NJKris]

Don't think you need to use GoPower just because a sticker says. Renogy makes great panels at half the price. Inlet on side goes direct to batt, so you would need a charge controller for the portable panel.