How big of a solar system is enough?

[Fireballsocal]

While planning out the addition of solar to my 2009 Lance 1880, I gravitated to the 160 watt systems right off the bat. It's what the new trailers come with and seems to be a common wattage available. Now I am questioning whether I need that much and if I would be better off saving a few bucks. I generally am a spend now, cry later consumer but more opinions are welcome.

Current camping is boondocking but I hope to start hitting more National and state parks, with or without hookups. I have a Yamaha 3000 generator for running the air conditioner but look forward to not having to lug it around when it's cool. Basically, I need the solar to keep the batteries topped off in storage. When I am out camping sans generator, I'd like the panel to provide enough juice to extend my camping for a few days off grid. Say, my 2 12V batteries last me a 2 day weekend in the winter running the heater etc., I'd like to extend that to 4 days roughly.

Again, I am more inclined to spend the money on the bigger system if justifiable but don't have a benchmark to hold that 160 watt system against.

[Lwiddis]

Tracking, I put 300 watts on and it works great for a 240 amp battery set - two sixes. Do it again? I'd go 400 watts in solar panels. Good to be over...a pain to be short in a shady campsite cuz I don't want to break out the generator.

[westend]

Panels are relatively cheap. It invites putting more on the roof than most folks need.

A good first step is accurately estimating how much power you currently use. That number will dictate what you need for panel wattage. Be sure to over-panel so that cloudy days and increased power use can be had. Solar is kind of addictive, once you have free power, you'll start thinking of what else it can bring you.

160W would be considered a maintenance setup, enough to keep batteries charged in storage and enough to replenish two batteries over a day or two of full sun if needs are modest.

FWIW, I have 300 AH of battery capacity and a 235W panel. I run a small 120V fridge and am getting by if there is full sun. I may add more wattage in the future just so I can take my eyes off the battery monitor. I may increase my battery capacity, also.

[corvettekent]

If all you want is four days then just add two more batteries.
Now if you want more then solar is the way to go. You should have 1.5 watts of solar for every anp of battery, so if you are going to stay with two 105 amp batteries then 315 watts of solar or two 160 watt panels.

[bobndot]

Why not install a battery cut off switch while in storage ?

[Colo_Native]

I put 510 watts on mine maybe over kill but the price for the panels was to good to pass up.

[Trackrig]

I have a 26' trailer and will try to get 400W up there. After putting out the time and energy to install it, go with an extra panel or two and be done with it instead wishing you had more and then working on it again next year.

Bill