advice/comments for my rv solar system?

[jimindenver]

Sunking

You still don't get it. he is in a trailer and it doesn't work that way. Motorhomes are different, but with trailers you are just not going to get the charge you are advertizing. Don't believe me, ask on a actual RV forum, they will laugh. That 7 pin is good for 10a max even with a isolator and if his 2 batteries are down to 50%, ummm geee, 8 hrs of driving PLUS the tapering of charge. Yeah right. He would be better off turning the truck around and slapping some jumper cables on it while it ran.

MH's have heavy duty alternators and heavier wiring to make their charging possible, towables are a different beast.

[tolbert]

OK do you have any idea what that means?

It means your batteries are only good for about 750 watt hours per day. It means you need a panel wattage of roughly 400 watts if using a 40 amp MPPT, or 600 watts if using PWM. It means you can only support a 400 watt inverter.

750 watts of power is not very much power. In fact if you drove the RV every day you would not need any solar, all it would take is a $50 battery isolator and run your RV engine 1 hour per day to recharge. What are you going to do on cloudy days? You do know you have to park in full sun with no shade from sun up to sun set right? Hope you have a generator.

Sunking

You still don't get it. he is in a trailer and it doesn't work that way. Motorhomes are different, but with trailers you are just not going to get the charge you are advertizing. Don't believe me, ask on a actual RV forum, they will laugh. That 7 pin is good for 10a max even with a isolator and if his 2 batteries are down to 50%, ummm geee, 8 hrs of driving PLUS the tapering of charge. Yeah right. He would be better off turning the truck around and slapping some jumper cables on it while it ran.

MH's have heavy duty alternators and heavier wiring to make their charging possible, towables are a different beast.

now im just confused?

will my solar setup charge my batteries at all during the day?


here are my stats for a few things i run in the trailer.

tv | 19w. 0.26 amp


baby camera | 3-5w. no reading on amp

iphone | 7 watt. .11 amp

macbook | 20-30watt. .50 amp

wifes flat iron is 170-200 at start. then down to 75ish. 2 amps

[thastinger]

The problem with solar on an RV is the angle of the panels and that it all has to be 12V. When those batteries die on you buy 2 of the 6V golf cart batteries and wire them up in series, will be a little more capacity than you have now and will give you longer service life. Right now you have 2 batteries in parallel.
Do you have a generator? Because you don't have enough panel capacity, whats your plan for the AC in the Summer time?

[jimindenver]

I wanted to add that your trailer will have parasitic draws that would drain the batteries even sitting in storage. The water heater and fridge have control panels that draw 12v, there is a propane detector also. I amassuming you will be using the pump and fans on occasion too. make sure you account for all of the draws.

[tolbert]

The problem with solar on an RV is the angle of the panels and that it all has to be 12V. When those batteries die on you buy 2 of the 6V golf cart batteries and wire them up in series, will be a little more capacity than you have now and will give you longer service life. Right now you have 2 batteries in parallel.
Do you have a generator? Because you don't have enough panel capacity, whats your plan for the AC in the Summer time?

never worried about a/c in the summer. i just wanted to be able to run some things as i stated in earlier posts.

[thastinger]

now im just confused?

will my solar setup charge my batteries at all during the day?


here are my stats for a few things i run in the trailer.

tv | 19w. 0.26 amp


baby camera | 3-5w. no reading on amp

iphone | 7 watt. .11 amp

macbook | 20-30watt. .50 amp

wifes flat iron is 170-200 at start. then down to 75ish. 2 amps

You should have just bought a decent 300W PSW inverter with a cig adapter (my RV has an cig lighter receptacle, so I assume yours does as well) and ran all that from there and bought a blue or red inverter gen to recharge the batteries once a day.

[tolbert]

I wanted to add that your trailer will have parasitic draws that would drain the batteries even sitting in storage. The water heater and fridge have control panels that draw 12v, there is a propane detector also. I amassuming you will be using the pump and fans on occasion too. make sure you account for all of the draws.

understood. i wonder when i run the engine on my truck, does it charge the batteries?

[jimindenver]

No worries about angle if you use it portable. With a panel that small it would be an advantage to be able to chase the sun. OTOH it is a pain to store and handle which mounted systems are more hands off. Always a trade off.

[thastinger]

never worried about a/c in the summer. i just wanted to be able to run some things as i stated in earlier posts.

Have you ever been inside an RV that is sitting in the Sun (required for your panels to do anything) in the Summer? Your Wife is going to cause you more pain than you can imagine if that is your plan.

[thastinger]

understood. i wonder when i run the engine on my truck, does it charge the batteries?

On a TT, yes, to some extent anyway. If you crawl under your truck and take a look at the wires for your 7 pin plug, you'll notice they are small, give the voltage and length of transmission, that tells you that it isn't going to be much. It's most to run the 12V logic in the fridge while the fridge is set to propane mode and you're driving to/from your destination. If the trip is long enough it could charge them fully but I wouldn't expect more than 5-8 Amps to be going through those 7 pin wires.

[tolbert]

Have you ever been inside an RV that is sitting in the Sun (required for your panels to do anything) in the Summer? Your Wife is going to cause you more pain than you can imagine if that is your plan.

i live in san diego.

[thastinger]

No worries about angle if you use it portable. With a panel that small it would be an advantage to be able to chase the sun. OTOH it is a pain to store and handle which mounted systems are more hands off. Always a trade off.

The OP said he hard mounted them to the roof and sealed them in, I can only assume that means they are at a 0 degree angle +/- a couple degrees.

[thastinger]

i live in san diego.

Ok so it is 75 and sunny all the time where you are, is this your house or do you plan to travel with it?

[jimindenver]

understood. i wonder when i run the engine on my truck, does it charge the batteries?

You will get SOME charge, not much. RVs as they come out of the factory are really made for shore power and short runs between hook ups. The 7 pin connector is really more of a life line to keep it going between those hook ups. To convert a RV just to off grid/ dry/ boondocking can be done in a number of ways but the truck is the most expensive generator there is. Even people with motorhomes don't sit in a site and run their motor for charging, they have built in generators or smaller portables that they use.

We run A LOT more solar than you are talking, nearly 10x the panel. Still we can use our microwave, hair dryer, auto drip coffee maker, TV/SAT, vacuum and even a small air conditioner and we don't take a generator unless it's the monsoon season. Like someone said, you can do anything, it just takes money and understanding.

The best thing for your batteries is to keep them charged, not let them go below 50% and not allow them to stay in a partially discharged state. Make sure you are using the manufactures charging regime and keep the distilled water ready to top them off as needed.

[tolbert]

You will get SOME charge, not much. RVs as they come out of the factory are really made for shore power and short runs between hook ups. The 7 pin connector is really more of a life line to keep it going between those hook ups. To convert a RV just to off grid/ dry/ boondocking can be done in a number of ways but the truck is the most expensive generator there is. Even people with motorhomes don't sit in a site and run their motor for charging, they have built in generators or smaller portables that they use.

We run A LOT more solar than you are talking, nearly 10x the panel. Still we can use our microwave, hair dryer, auto drip coffee maker, TV/SAT, vacuum and even a small air conditioner and we don't take a generator unless it's the monsoon season. Like someone said, you can do anything, it just takes money and understanding.

The best thing for your batteries is to keep them charged, not let them go below 50% and not allow them to stay in a partially discharged state. Make sure you are using the manufactures charging regime and keep the distilled water ready to top them off as needed.

when sitting on the side of the house...what should i be doing? we use it about once every two months.