Decided on a Trailer and Solar Question

[Kudzu Asheville]

Hi All,

After much consideration, my husband and I have decided to purchase an Alto R-1723. It isn't a fiberglass RV but we think it will work well for us. Even though it's not a FGRV, it is a lightweight trailer, and I'm hoping I can stay involved in this forum because I am learning so much from you all.

Our trailer is a new dealer model. We would like to have them add the solar system and they would install Solar Flex 200 Watt panels (2 for a total of 200 Watts I believe) with 30 amp Digital Solar Controller. The brand is Go Power made by Carmanah Model # GP-Flex-200.

Is there anything else we will need with the solar system, or will that, along with our battery, be suffficient?

Thanks so much!
Leslie

[KevinScamps]

That's a lot of solar power for one battery. If you need that much power you also need a bigger battery, otherwise you can chill out on the solar panels. Spend the money on cheap LED lights. I have a single 30 W panel and I run lights and charge computer battery. My battery is always full at the end of the day.



Rule of thumb:

0.3 x Rated watts = Amp-hours/day

[Ray N]

Wow, that is a really nice and innovative trailer. You are sure to attract a lot of people wanting tours. Sorry, but I'm not familiar with solar, so I can't help you with that - just come down to Florida where all the state parks have electricity!

[Kudzu Asheville]

Originally Posted by KevinScamps

That's a lot of solar power for one battery. If you need that much power you also need a bigger battery, otherwise you can chill out on the solar panels. Spend the money on cheap LED lights. I have a single 30 W panel and I run lights and charge computer battery. My battery is always full at the end of the day.



Rule of thumb:

0.3 x Rated watts = Amp-hours/day

Thanks Kevin. I am an RV novice, and would like the freedom for boondocking, but am having a hard time getting my head around how much solar we are likely to need. I want to go ahead and get it installed in Canada where they are familiar with the Alto, so I'd like to get it done now rather than later, but that makes it tricky to predict what we'll need. This trailer already has LED lights. My guess is I would be using solar for LED lights, water pump and the fantastic fan, as well as charging electronic devices. Also, maybe an extra fan or two, and potentially a radio. The fridge is propane/electric, so I wouldn't use it for that, and the water heater is propane as well. My understanding is that it won't work for my heat pump/air conditioner or microwave.

Is there any advantage to more watts to recharge faster?

Sounds like I should consider fewer watts and more battery power.

[KevinScamps]

No advantage to charging faster. You just want to be fully charged at the end of everyday. Solar power is not going to help with the ac. You could be like some people who run a dc refrigerator during day. 100w should be plenty. For lights and computer, small tv ect...

[Kudzu Asheville]

Originally Posted by Ray N

Wow, that is a really nice and innovative trailer. You are sure to attract a lot of people wanting tours. Sorry, but I'm not familiar with solar, so I can't help you with that - just come down to Florida where all the state parks have electricity!

Thanks Ray!

[mmcwhort]

Originally Posted by Kudzu Asheville

My understanding is that it won't work for my heat pump/air conditioner or microwave.

No, but it will work for the roof fan and an electric mattress pad, which is all you need 8 months out of the year. As for the Microwave, you can absolutely run that off of the battery as long as it's not too big. Here's a 12V microwave that I was thinking of getting. These are popular with truckers.

Sounds like I should consider fewer watts and more battery power.

Meh... it depends. A typical RV battery has around 100 amp hours of capacity. But that number is misleading because you're not supposed to run it completely dead, otherwise you'll damage it. You want to keep it at least 50% charged at all times. So once you've used 50 amp hours, it's time to recharge.

A 100 watt panel puts out about 6 amps in full sunlight. That means you should be able to bring your battery back up to 100% within 8 or 9 hours if the weather is good. So under ideal conditions, a 100W panel is a good match for a single RV battery.

But under not-so-ideal conditions, you might want 2 panels. For example, what if it rains for half the day? Or what if your trailer is parked in the shade? What if you want to run your coffee pot, your ceiling fan, and all of the lights when you wake up in the morning? You would want enough power to cover your daytime usage AND recharge the battery at the same time.

Personally, I'd get both panels. It's better to have it and not need it, than need it and not have it.

[Timber Wolf]

I am a Solar newb, still investigating it all but plan to start soon with a couple of panels and a contoller. The rough rule of thumb as I see it is to double everything. That sounds bad and simplistic but you only want to use 50% of your battery anyway so bamm, right off twice the AH in battery needed. You actually may want more battery then that as the less you discharge them the longer they last, and reserve capicity is always a good thing for those cloudy, rainy days (so maybe 4X is not too much?). Then the panel question. Maybe you usually don't happen to find sites that have the ideal orientation to ol' Sol, or your panels are mounted flat on the roof instead of the ideal winter-spring-summer-fall angle, well add more panel (2X). And then there is the controller and wire. To go bigger up front is cheaper than changing them out later if you decide to add panels, and bigger wire means less voltage drop. And half again or twice as much controller is not half again or twice as bulky, heavy, or expensive.

[MCDenny]

Be sufficient for what? To answer your question you need to figure out how much electrical energy you will want per day and how many days you want to go without plugging in and how much sun will be shining on your roof.

With the very minimal electric needs ( led lights, phone and computer recharging) ill bet you could easily go a week without recharging.

It's possible just adding another battery, no solar, could be all you need.

You have to define what you need before anyone can give you a good answer.

Ps we have a 12v fridge plus lights, computer charging, etc and 220 ah battery capacity. We could go 4 days without recharging. We now have 100w solar panel. So far it has kept the battery fully charged.

Maybe 200w would be needed if you camp off the grid in a cloudy place often.

[Kudzu Asheville]

Thanks all! The difficult thing is not having the experience to know what we'll use with regards to amp hours. If we weren't so far from Canada, I'd be more inclined to wait.

We want to be able to be off grid in national or state parks for up to several days, and be able to use lights, water pump, fantastic fan, maybe use other fans and radio and charge electronic devices. We'll also be running our fridge and hot water on propane. It would be nice to have enough excess to meet future needs that may arise.

[stev]

Regarding flexible solar panels, here is a review on one.
Not the same brand you are looking at, but looks a like.
I don't know if they are the same? Just with different brand names on them.

Flexible 100 Watt Solar Panel | Solar Panels

[cpaharley2008]

You can always add an extra battery later, easily, a lot more easy than an extra solar panel. Get the solar and camp in it, then you can make an informed decision.

[mmcwhort]

FYI - There are 12V refrigerators that will run on solar power. With a 100W panel, you could theoretically run it indefinitely when you're boondocking. It would save you a lot of money on propane.

[stev]

I saw a neat little 12 vdc, Ice Box size frig at Costco for around $90.
I have had these before and they seem to work good.

[sparky1]

Wave box draws (50 amps)-Cost $279 plus shipping, lots of drain off any battery to operate that thing,
my 2 cents.

[peterh]

A good, general rule of thumb for non-fulltimers on matching your battery size to your solar panel size is to have (roughly) one amp at 12 volts of storage for every watt of solar panel you've installed. In other words, a 100w panel should be matched with a 100AH deep cycle battery. (That's two 100AH 6V batteries for the 6V aficianados.)

Full-timing is a little different, because full timers are tucked away inside their trailers during the winter when there is less sun during the day. Less sunlight means you need more panel to charge the same sized battery. How much different depends a whole lot on where you spend your winters: if you're in the southern US it's a 1.5:1 ratio, 150w of panel to 100AH of battery capacity. Here in southern Washington State, I'd match 300w of panel to a 100AH battery. (3:1) If you live in Canada, particularly northern Canada, heaven help you, you'll never get enough sun, even if you scrape the snow off.

[Carol H]

Originally Posted by mmcwhort

FYI - There are 12V refrigerators that will run on solar power. With a 100W panel, you could theoretically run it indefinitely when you're boondocking. It would save you a lot of money on propane.

If your parked out in an open sky spot with lots of sun thats very true, but when parked in a heavy tree covered area and there is a lack of sunshine for a few days such as what happens here on the West coast often... maybe not. Have more panels for when the slight glimpse of the sun appears for a short time is always better if your wanting to run a fairly high number of 12v appliances etc.

[Carol H]

Originally Posted by peterh

If you live in Canada, particularly northern Canada, heaven help you, you'll never get enough sun, even if you scrape the snow off.

heck you may not even get enough in the middle of a rainy July!

[Night Sailor]

200 watts sound good. You can always add more later if you find you need it. If you are boondocking the advantage to more power is you can recharge on an overcast day.

You should consider an MPPT charge controller if you are boondocking for extended periods. The included charge controller is suitable for someone weekending. You won't get the maximum power out of those panels without MPPT technology . It will provide 30%-35% more power.

As already mentioned, your batteries should be sized larger. You should have
200 Amp Hour battery capacity for 200 watts

Very cool camper. I enjoyed reading about it. Aluminum framing means it will last as long as an egg camper. You will have a lot of fun with it.

[Kudzu Asheville]

Originally Posted by Night Sailor

Very cool camper. I enjoyed reading about it. Aluminum framing means it will last as long as an egg camper. You will have a lot of fun with it.

Thanks Conrad! We are excited to get camping!