Stupid solar power question

Joined
Apr 13, 2025
Posts
11
Location
New York
I'm totally new to this solar power thing on our 5th wheel. My question is when hooked to shore power is the solar power wasted? I've searched for diagrams showing how solar and the battery charger connect to the batteries but can't find anything. I would like to think that the solar is the priority charger taking some of the load off the AC charger, allowing a few more amps AC current available to the coach. I did notice over the last few cloudy days you don't get much power. I had run down the batteries to about 12 volts while filling the water system with the pump, It is difficult to plug my 5th wheel in when parked at our house. That was on a sunny day. The next few days were cloudy and the batteries did not recover. I have the 2 200W panels.
 
If you wish to just use your solar on a sunny day, then just turn the breaker off for the built in converter. But your solar, when plugged in does not do much to solely override the built in converter. But the key to solar is the battery capacity that you have to maintain proper 12 volt. 400 watt is fairly minimum if you anticipate being off the grid more than being hooked up. If your unit reflects your login, its my opinion that you really need to upgrade your solar capacity and possibly battery capacity,, if you just have a factory package relating to the 2 200 watt panels.
 
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With my LFP batteries and the converter set to LI, the voltage is higher from the converter than solar, so the solar doesn't get used much during the day, if at all. As suggested, if I wanted to use the solar while hooked up to shore power I would need to turn the converter off. This is with the factory setup and overlanded II. More sophisticated systems may work differently.
 
Not a bad idea. Full sun, 400 watt's that's what little over 3 amps AC current. We all have to do our part right!
Well we don't buy these units solely with the idea that we must consume less artificially generated power to run the essential equipment. So you need to be realistic when matching needs with your power replenishment setup, battery capacity included if you are primarily planning on using solar to be comfortable and to make sure you do not attempt to run your equipment on low voltage. You will find out quickly 12 volt equipment, in particular will give you backlash if you attempt to constantly operate on low voltage.
 
As above, the solar is to provide some power when off grid camping. 400 watts of maximum output would probably put out a kilowatt or so on an average day. Running your AC, TV, micro, toaster, etc. would take quite a few kilowatts.
My little 100 amp/200 watt setup means I can run my furnace in cold weather and have plenty for occasional phone charging, lights, etc. plus 12 volt fans in hot weather.
 
We rarely camp off the grid. The one trip we planned on dry camping I took a generator in the back of the truck, which we only used a couple of hours the nights we weren't hooked up. There was no need for AC where we were. I would never expect to run the big AC loads off the inverter, just the refrigerator, which by the way is the first time I have not had a propane powered fridge, so i am experimenting running fridge off the batteries to see if it will stay powered overnight. I have to run about 300 feet of extension cords to plug my 5th wheel into shore power, or hook up the generator, but I'd rather not run that all the time just to cool the fridge.
 
That's a long distance to run a cord unless its a heavy gauge cord.There is no shame in giving your battery or batteries a boost before sundown, or as you eat and clean up before settling in for the evening when using the unit. While I have a residential fridge, the draw is similar to what I dealt with with the Ever Chill 12 volt, which in my case never chilled for more than two days. Then it would freeze up and dealers flipped me the bird when our conversation turned to bringing it in and monitoring it after restarting it and monitoring it for more than two days in a row.

But with the inverter drawing on the batteries I crank up the fridge temps at a higher rate during the day and then turn it down before heading to bed. This conserves juice and the risk of constantly running the lead acid batteries down. This also requires more juice to recharge strictly on solar during the day when the amount of solar can vary.
 
Not really answering the initial question, but If you’re serious about being off the grid and still using LA batteries, you’re fighting a losing battle. Best mod we ever did was swap the twin 64ah LAs for a 300ah LiFePO4. It weighs much less, lasts a lot longer and you get about 80-85% of the advertised amperage as opposed to the 50% from a LA; plus you can monitor the charge/discharge rate via Bluetooth.
 
Not really answering the initial question, but If you’re serious about being off the grid and still using LA batteries, you’re fighting a losing battle. Best mod we ever did was swap the twin 64ah LAs for a 300ah LiFePO4. It weighs much less, lasts a lot longer and you get about 80-85% of the advertised amperage as opposed to the 50% from a LA; plus you can monitor the charge/discharge rate via Bluetooth.
Buying batteries online, where the prices are all over the map, for similar AH is a crap shoot. Currently Renogy is close to a grand for a 300 AH lithium battery, which I can buy a lot of lead acid batteries for that price and get similar output if I use my brain accordingly. While there are some limitations as it relates to the amount of discharge that I can drain my batteries down to, the key is just being sensible.with my use.

I personally offset my off the grid needs with a small boost, a couple of days with my set up if we on the road in remote areas. If I need air, well I cannot install enough lithiums to run it enough to cool the TT under normal conditions.

The rest of the brands are just a crap shoot, when you read all the reviews. The first thing I do is to read the lowest review section. While Renogy customer service is suspect too, overall their product has been decent, if I was to go the lithium direction. While top end rvs and motorhomes may justify going the high end stuff, Battle Born for a simple travel trailer will not be getting my money. I think a lot of other people using their like models are in the same boat.

And I think average campers rarely keep their units long enough to experience the perceived 10 year durability promotion. If you go that route, the choice is narrowed for companies that you can depend on being around if you do have a problem.
 
Buying batteries online, where the prices are all over the map, for similar AH is a crap shoot. Currently Renogy is close to a grand for a 300 AH lithium battery, which I can buy a lot of lead acid batteries for that price and get similar output if I use my brain accordingly. While there are some limitations as it relates to the amount of discharge that I can drain my batteries down to, the key is just being sensible.with my use.

I personally offset my off the grid needs with a small boost, a couple of days with my set up if we on the road in remote areas. If I need air, well I cannot install enough lithiums to run it enough to cool the TT under normal conditions.

The rest of the brands are just a crap shoot, when you read all the reviews. The first thing I do is to read the lowest review section. While Renogy customer service is suspect too, overall their product has been decent, if I was to go the lithium direction. While top end rvs and motorhomes may justify going the high end stuff, Battle Born for a simple travel trailer will not be getting my money. I think a lot of other people using their like models are in the same boat.

And I think average campers rarely keep their units long enough to experience the perceived 10 year durability promotion. If you go that route, the choice is narrowed for companies that you can depend on being around if you do have a problem.
I have two of these...very solid build battery with good components from the teardown reviews on YouTube. price is reasonable for the quality....not a crap shoot...no corrision...no watering....once you change over you'll never go back...Battle Born are way overpriced Vatrer 300ah
 
I know it's a long run. On my old 5th wheel I've measured the voltage at the trailer and it's usually about 110-115V when first plugged in. The converter was the only load so it was well within the 105-130V for the converter. I also had a propane refrigerator so no electric motors running on the extension cords, just the electronics for the fridge. I haven't run the extension cords yet for the new trailer, just relying on solar to keep batteries charged after running the water pump to de-winterize, a few lights and opening/closing the slides. Today was sunny all day and the batteries were at 13.2 at dusk, so I may not need to use the extension cords when preparing for a trip. ie loading food into the fridge, which BTY is the end of May
 
To get the same usable power as my 57lb 300ah Li (about 255) you would need more than 5 100ah LAs batteries (50ah each) at roughly $200 a piece and they each weigh about 50lbs. In my Eagle, I can fit maybe 3 24 group batteries so I would have to find a different location. The 300ah LI typically comes with a 10 or 11 year guarantee or about 3000 charging cycles, the LAs 24 months maybe. It’s a bit of an initial investment I agree, but well worth it.
 
With my LFP batteries and the converter set to LI, the voltage is higher from the converter than solar, so the solar doesn't get used much during the day, if at all. As suggested, if I wanted to use the solar while hooked up to shore power I would need to turn the converter off. This is with the factory setup and overlanded II. More sophisticated systems may work differently.
You need to go into the BMpro and set the solar controller to the proper battery type for it to function correctly with the Li batteries as well as set the Ah. Then your solar will actually do something.
 
You need to go into the BMpro and set the solar controller to the proper battery type for it to function correctly with the Li batteries as well as set the Ah. Then your solar will actually do something.
Thanks for your suggestion, but it is set correctly with the available settings.

My GoPower 30 amp MPPT controller when set to Lithium is 14.4v bulk then 14.0v float, my convert in Lithium mode is 14.6 volts....the converter ends up overpowering the output of the solar controller so as to have 0 amp output. Now, if the batteries are not fully charged, the solar will contribute, but if the batteries are fully charged, all the power is coming from the converter to run the 12 volts items in the RV.
 
Thanks for your suggestion, but it is set correctly with the available settings.

My GoPower 30 amp MPPT controller when set to Lithium is 14.4v bulk then 14.0v float, my convert in Lithium mode is 14.6 volts....the converter ends up overpowering the output of the solar controller so as to have 0 amp output. Now, if the batteries are not fully charged, the solar will contribute, but if the batteries are fully charged, all the power is coming from the converter to run the 12 volts items in the RV.
Now we're getting somewhere. If you want solar to supersede shore power, you'll have to find the manual settings so the solar controller is outputting higher voltage than the converter. How and even if you can set it with that granularity is up to the devices capability and configuration.
 

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