I have a 2023 Grand Design 2400BH with 1 – 150w solar panel and 2 – 6v batteries.
So I am wondering how everyone is combating the 12v fridge when off grid/no service camping? .. We are really struggling to keep a decent charge throughout the day.. We are equipt with a 3300w gen, which isn't that loud but also is not a whisper either, so we don't like to run if we do not have to. Also, I just picked up a canadian tire special movable solar panel (100w) to help keep the charge up, but it doesn't seem to be doing jack all.
I am pretty sure I know the solution, but just looking for some other tips or tricks save some battery life that do involve parking the trailer in a wide open field to get optimum sunlight.
Most of these are designed to be used in an RV park with hookups. If you prefer dry camping, you’ll need to upgrade your battery bank and solar system.
First replace your 6v lead acid batteries with LiFePo4. They charge much faster to capture what limited solar you have available and/or reduce the time your generator needs to be run to charge the batteries. LiFePo4 takes full current until they are fully charged vs lead acid which goes into an extended absorbtion phase that takes forever to top off. Plus you should only be taking lead acid down to 50% SOC, where LiFePo4 you can take it down to zero with very little long-term degredation. Once you have LiFePo4, then you can expand your solar capacity with MPPT controller(s) to maximize the solar capture.
Note: to fully take advantage of LiFePo4, you may need to replace the converter/charger in your trailer if the OEM one doesn’t have a LiFePo4 charging profile. A lead-acid charging profile won’t damage the battery, but could take extra long to charge than needs to and may not fully charge the LiFePo4.
This is 100% a math problem. Any fridge has some power draw rate. So you can either increase production (by more solar panels or as you’re doing, a generator) , increase storage with more batteries (and more production as the daylight hours are limited), or decrease usage (smaller/more efficient fridge, etc)
According to an online calculator I found, if you have a 200ah battery bank, you can pull 200w(just guessed at a wattage) for 10 hours. This may be sufficient. Now you need to identify a solar charging setup that can bring these batteries up during the day. You should clearly see that in this scenario 150w won’t cut it. (Don’t forget it’s 150w PEAK)
You don’t have nearly enough solar. 400-500w of solar would probably get you there, depending on a lot of factors. Also, don’t trust the wattage rating on most solar panels, companies lie about that. There are panels that do produce their rated power or even more, just be careful and look at reviews.
You didn’t mention the AH of your 6v batteries, so I can’t know if you have enough battery bank. I’m guessing you’re fine and just aren’t bringing in enough solar to get them charged up.
If you’re running an inverter, turn it off until you need it. They waste tons of energy.
Propane refrigerators aren’t standard in new RVs?
The short answer is we upgraded the battery and solar on our rig. Our rig had two 12v 100Ah lead acid batteries and a 100W solar panel. The batteries would drain nearly to dead from minimal overnight usage (charging phones, lights, water pump, refrigerator, blower for the propane heat) and would not recharge significantly from the solar. And that was even with no inverter usage and running the generator if we needed the microwave or something.
We upgraded to 3 LiFePO4 batteries (which tripped our capacity since lead acid batteries only have half their rated capacity) and 860W of solar. Now our “baseline” overnight power usage with the 12v fridge and whatever else we want to do is about 30%. Plus we can use the microwave, induction burner, etc… without worrying.
Just need more juice! All there is to it.
Swapping to some lithium batteries and adding more solar, or just running your genset for a few hours each day, is the solution.
I have 400w of solar and 200Ah worth of lithium batteries and that runs my fridge indefinitely most of the year. (Sometimes in the dead of winter with long overcast stretches I have to run the generator a bit.)
Source: The 12v Fridge……
