Solar question

[bookem15]

I have a 30 ft 5er and use 2 6v golf cart batteries and always take my 4500kw generator with me. I hate listening to the generator so I am looking into solar. I use the led house lights at night for about 4-5 hrs and the stereo most of the day. My wife watches a movie at night before bed and that is about the only power consumption. Question is would a 100-200 watt solar system charge my batteries enough to avoid running generator every other day for an hour?

Thanks for any and all help.

[LVJ58]

We have a 38 ft class A with a 110w solar panel and a Blue Sky 2000-E 25 amp controller that keeps our 4 6v house batteries and the 12v chassis battery charged.

Good luck and safe travels.....

[bookem15]

With me only having 2 batteries instead of 4 hurt me any?

[babock]

2 golf cart batteries is a little over 100AH usable. Assuming 5 hours equivalent solar per day, you need output of 20A. 20A under perfect condition and aiming is 400W of solar. Assuming a 30% drop in efficiency due to a no tilt panel, I would at least go for 600W.

Personally, I am putting up 700W although I decided to go with lithium with 180AH usable.

An MPPT controller will get you a little more efficiency but you typically want to put the 18V panels in series to take advantage of it.

I am doing this sizing for you assuming you use the whole 100AH which I think is a good thing to do since you may have cloudy days or run the heater which is a heavy hitter.

[drdarrin]

If you are going to be relying on solar to power your rig (except air conditioning), I’d opt for double the batteries and and at least 500 watts of panels.

Our 5er has a battery monitor, 520W of panels, 4 batteries, MPPT controller and a 2kw inverter. We use less than 10% of our available capacity in a normal day. So far, our batteries have never gone a day without being fully charged.

[450Donn]

Well, if it were me, oh wait it is me.
4 golf cart batteries, 250W of solar. We can go for days. My wife is pretty much like yours. TV is her thing. But instead of movies we use satelite.
So if it were me again, I would up battery capacity, and add more solar to your idea and go.

[babock]

Originally Posted by 450Donn

Well, if it were me, oh wait it is me.
4 golf cart batteries, 250W of solar. We can go for days. My wife is pretty much like yours. TV is her thing. But instead of movies we use satelite.
So if it were me again, I would up battery capacity, and add more solar to your idea and go.

The problem with 4 batteries and only 250W of solar is that you can leave your batteries undercharged for days if you happen to have one large consumption day. I am assuming you run a genny when that event happens?

[MisterT]

I think that the sentiment is right on track, as having not enough battery storage means you could be 'wasting' solar power(but who complains about having 'too much', right?!), and having too little solar power could be leaving your batteries undercharged.... so what gives?

nothing. It's all guesswork. Your guess is as good as you need it to be for your needs and circumstances, as everyone uses electricity differently.

Sun is also the big factor, without it nothing happens, other than dead batteries. Shade, cloudy and rainy days, and placement/tilt of the panels can also 'tilt' the numbers against you.

You can only start with what you think is a good 'starting' point, then go from there as you see how your camping style and your electrical usage stacks up with your battery storage and panel power. 4 -6v batteries and 4 - 100w panels is a good 'average' starting point. Go from there.

[rarebear.nm]

Yes, everyone's power usage is different and no one solution fits all.

I always recommend you perform a real energy audit (many threads on this) and determine your average daily power needs. From that you can determine the battery capacity and solar sizing. If done correctly it should work out well for you.

In my case we have four 6 volt batteries with 460 Ahrs usable, 1050 watts solar and a Morningstar MPPT 60 controller. I sized this system to fully recharge on a cloudy rainy day with low sun angles. So far even on cloudy morning the batteries have always reached 100% by 10:00 am. This includes running the furnace and other normal LED lights, water pump, frig controller, etc.

[Harrysait]

Originally Posted by bookem15

I have a 30 ft 5er and use 2 6v golf cart batteries and always take my 4500kw generator with me. I hate listening to the generator so I am looking into solar. I use the led house lights at night for about 4-5 hrs and the stereo most of the day. My wife watches a movie at night before bed and that is about the only power consumption. Question is would a 100-200 watt solar system charge my batteries enough to avoid running generator every other day for an hour?

Thanks for any and all help.

Bookem15
Your 2 GC batteries are good for 100aH per day but but to get long life from them you do not want to go below 50ah or 50% state of charge.
Just guessing, your nightly tv 20ah, some led lights 5ah, stereo 10ah, inverter for 120v 10ah. These add up to 45ah so close to your battery limit. It is ok to go over 50% soc once in a while but not too often. If my guess of your usage is close your 2 batteries will work, if you can recharge them to 100% the next day. Your job is to come up with your own estimate.

So now to solar, a 100 watt panel could work but everything would need to be perfect, no shade, bright sun, etc. I suggest to start a 250 watt 24volt panel, Vitron 100/30 MPPT solar controller,. This will allow you to expand to 500 watts without changind the controller, at a later time.
The 250 panel will charge at about 15amps, or a good day about 70ah back in the battery. So you may have excess but that is better than short!

With 500 watts and 4GC batteries you can easily use 100ah per night and be at 100% soc by noon the next day, in good sun.

If you start small the next panel needs to be the same size if in series for best efficiency, panels are getting much lower in price so don't scrimp there. Nothing is damaged if your panel is outputting more than you can use, the controller takes care of it.

Have fun.

[twinboat]

Originally Posted by Harrysait

Bookem15
Your 2 GC batteries are good for 100aH per day but but to get long life from them you do not want to go below 50ah or 50% state of charge.
Just guessing, your nightly tv 20ah, some led lights 5ah, stereo 10ah, inverter for 120v 10ah. These add up to 45ah so close to your battery limit. It is ok to go over 50% soc once in a while but not too often. If my guess of your usage is close your 2 batteries will work, if you can recharge them to 100% the next day. Your job is to come up with your own estimate.

So now to solar, a 100 watt panel could work but everything would need to be perfect, no shade, bright sun, etc. I suggest to start a 250 watt 24volt panel, Vitron 100/30 MPPT solar controller,. This will allow you to expand to 500 watts without changind the controller, at a later time.
The 250 panel will charge at about 15amps, or a good day about 70ah back in the battery. So you may have excess but that is better than short!

With 500 watts and 4GC batteries you can easily use 100ah per night and be at 100% soc by noon the next day, in good sun.

If you start small the next panel needs to be the same size if in series for best efficiency, panels are getting much lower in price so don't scrimp there. Nothing is damaged if your panel is outputting more than you can use, the controller takes care of it.

Have fun.

2, 6 volt GC2 batteries will have at least 200 AH of capacity, not 100 AH as you stated.

[babock]

Deleted

[bookem15]

I just checked to make sure and I have the Duracell (deka) 230 mah 6volt go batteries. I have friend that is a sales person for deka and he advised getting a 100 watt would be fine and if I needed more just to add panels as l ok ng as control could handle more panels.

[bookem15]

Originally Posted by bookem15

I just checked to make sure and I have the Duracell (deka) 230 mah 6volt go batteries. I have friend that is a sales person for deka and he advised getting a 100 watt would be fine and if I needed more just to add panels as l ok ng as control could handle more panels.

So that would mean I have 200 amp hrs to deal with and charge