New RV Owner with power(solar) questions.

[jsw513]

Hi Everyone, I've enjoyed reading through the forums, and finally joined! I appreciate the wealth of information that is accessible here.

My wife and I recently bought a 1985 LeisureCraft. It's in pretty decent shape, although it needs some work. I recently had the generator serviced, replaced all the taillights, and just had a full tune up done on it. Seems to be running like a champ!

I've some questions about powering the RV, specifically with solar. I've read a bunch of stuff but I'm having a hard time fully wrapping my head around the idea. Currently there is no power converter in the RV. So I'm assuming my generator won't even charge the battery. Is this correct? It's got a 6v marine battery in it that's old, and I assume it will need to be replaced. All that I've read is that it might behoove me to get 2 6v golf cart batteries and wire them together. We will be primarily boondocking for a week at a time with no access to anything. We will run our generator sparingly and sporadically when we need to break free of the desert heat, and turn on the AC. I would like a solar solution to keep the batteries charged for recharging camera batteries, running the water pump, etc. Where is the best place to start? We will be frugal with our power consumption, but would like to insure that it's there, and available for us to use. I found the following solar kit, though the reviews say the charge controller is a piece of junk. Would this kit seem like enough to keep me alive with my above requests?

http://www.amazon.com/Renogy-Solar-Panel-Bundle-200Watt/dp/B00B8L8MD2/ref=sr_1_6?s=lawn-garden&ie=UTF8&qid=1404417370&sr=1-6

My generator technician also suggested I look intelli-power 9200 series as a converter. I'm still not able to wrap my head around how all these things play together. Is that primarily for when it's plugged into shore power? Thanks in advance for any and all advice! We are looking forward to getting on the road in this thing!

[pnichols]

True deep cycle 12V batteries do indeed exist, and in the common group sizes ... but you have to look for them.

We have a couple of Group 29 AGM wheelchair batteries in our RV. They get charged with the very quiet idling V10 and it's 130 amp alternator, the quiet built-in generator, or a 650 watt ultra quiet portable generator.

We like the high energy content and safe convenience of propane, including the refrigerator. In fact our formally all-electric stick house of over 35 years is finally about to get it's kitchen cooktop converted from electric to propane - along with the fireplace.

No sun or high-idle engine throttle is required for our drycamping ... only gasoline and propane. We could even if necessary in an emergency, go without propane because the built-in gas generator could do it all (except bake) from the main 55 gallon tank if we were to carry a conventional or induction hotplate along.

[2oldman]

jsw513 wrote:
Would this one battery be fine? Since it's 448 amp? Or would I need two to get to 12volts?

The 448 spec is: "Reference Crank Amps-32 degrees F (Amps)"

I do not know what that means, and, true deep cycle batteries are almost never rated in cranking amps since that's not what they're used for. And for that price, and size, there's no way that battery is 448 'amp hours'. It's probably more like 220, like similar batteries.

Yes, you need 2. Maybe you need to review that '12v side of life' 🙂

[DiploStrat]

jsw513 wrote:

Where/how do the alternators come into play?

Ndeke Luka is built on a 2013 Chevrolet Silverado 3500 HD with a diesel engine. The engine is factory equipped with two 125A alternators and two starters batteries. (Chevrolet also has a very sophisticated charging system.)

Each of the starter batteries is connected to the camper battery bank by a fused 1/0 cable. The batteries are connected by a Magnum Smart Battery Controller whenever there is a sustained 13.2v charge on either side and disconnected whenever the voltage drops to 12.7v. (12.7v is typically given as "full" charge at 70F.)

This means that the batteries are connected together whenever the engine is running, whenever there is any significant light on the solar panel, or whenever I am connected to shore power.

Typically, the camper batteries are fully charged at sunset. Cooking dinner is usually 30 minutes at about 150A discharge rate, using the induction cooktop and the convection microwave. Additional loads are the composting toilet, refrigerator, lights, music/TV, telephone and computers, heat, fans, or air conditioner. Breakfast is normally another 15 minutes of 150A discharge. The net result is that I am usually about 125Ah down at engine start in the morning.

Being 125Ah down on a 600Ah battery bank usually causes the camper batteries to demand around 150A from the alternators for an hour or so. On a sunny day, the batteries are usually fully charged by noon. On cloudy days, the recharge rate is obviously lower and much more dependent on running the engine.

The design goal was three days with no sun or engine run.

Air conditioning is the greatest challenge as the fan is 10A and the compressor about 50A. Clearly, air conditioner run is dependent on temperature; that is, how long and how often the compressor runs. One "cheat" is to run the engine for 30 minutes to an hour during the initial cool down, just as one might run a generator.

There is no magic in any of this.

[eric1514]

That battery is not a 448 amp battery. Two of them night get you 200+ amps at 12v, but you can do better on the price.

[jsw513]

http://www.lowes.com/pd_599952-50656-GC15_0__?Ntt=6v+golf+cart+battery&UserSearch=6v+golf+cart+battery&productId=50183775&rpp=32

http://tinyurl.com/l8tu5ps

Would this one battery be fine? Since it's 448 amp? Or would I need two to get to 12volts? The other 6v batts that I"m looking at are ~$100 and have about ~200 amps.

[Dakzuki]

jsw513 wrote:

tpi wrote:
The power converter is useful for recharge when hooked up to AC, or recharge when running generator.

I don't know how long you'll be camping at a stretch. But for some of us who camp less than a week at a stretch there is no need for the solar to completely keep up with usage. There can be a small daily deficit. This can be made up by the solar system once finished camping, or the power converter w/ generator use or a night in RV park along the way.

As one with small solar system (no plans to expand), I concentrated on the demand aspect too. I have all LED/fluorescent lamps. Laptop draws 13 watts. I carry enough blankets I can turn the furnace way down at night. I use propane for all heating tasks: coffee, baking, cooking-equipment that has already been provided by mfg.

This sounds a bit like where I'm at. My furnace is gas powered ( i think). I don't have a microwave. I would easily swap all my interior bulbs for LED to save power. Do you think 200 watts of solar is over-kill? We will be doing one 8-10 day trip annually, and we will be periodically running the generator during that time...say 1-3 hours a day. Am I overdoing it on what I think I need for solar?

200 watts is a very good start. LEDs will help as they use less than 20% for the same light output.

[Dakzuki]

jsw513 wrote:

PSW wrote:
I recently installed a Renogy system I bought from Amazon just like you had in your link, except it was the system with only one 100 watt panel, same controller. We boondocked for two weeks and were parked in partial shade most of the time and it did a reasonable job of keeping our batteries up (we have two 12 volts). I was pleased how well it did and frankly a little surprised but it obviously needed a little more juice because of our amount of use.

So, I have on order another panel and will add it next week, giving me 200 watts total. With that, we can boondock in partial shade and stay charged just fine, based on our experience with the one panel. The controller is criticized on the Amazon site by some buyers. All I can say is it worked just fine for me. The main criticism is that the wires don't stay tight in the controller. The screw that tightens the wire in each entry point operates a gate type slide which closes on the wire. I suspect many people are just sticking in the wire and turning the screw and may in fact not be securing the wire properly because they didn't have it all the way into the gate before turning the screw. Examine it closely under a good light before you wire it up and you will instantly see what I mean and I don't think it is a problem.

Paul

Good to hear you had a positive experience with it! We won't be running TV's or microwaves. Just outlets and water pumps, and such. You have 2- 12v batteries...can I assume that's more power than me getting 2 deep cycle 6v batteries?

In general you are better off with two 6 volt deep cycle batteries. They are true deep cycle rather than a hybrid as virtually all 12 volt batteries are.

[Ing46ram]

Thanks for the photos. It looks great. Hope you and your family will have lots of good times with it.

[jsw513]

Ing46ram wrote:
Wow, love Leisure Crafts wonder if you could add ,some pictures for us to see.

Here's a few of the exterior I just took. I would show you the interior, but it's in shambles right now, as I've pulled a sofa, all the cushions, and the carpet.

http://imgur.com/w9fhgYe

http://imgur.com/c9K5K1i

[Ing46ram]

Wow, love Leisure Crafts wonder if you could add ,some pictures for us to see.

[tpi]

jsw513 wrote:

tpi wrote:
In the desert you'll need the AC and the generator to do that. But that brings another thought-if you're running the AC half the time on generator, you really may not need solar at all. You can charge the batteries during the AC run time.

FWIW it is about $2. per hour for generator fuel in hot part of the day.

So, on average, about a half gallon of gas per hour? How quickly does the average generator recharge batteries?

With a power converter that starts at 14.4 volts, not too long. Especially in the desert summer where your night load should be low-no heater. For me, with my LEDs and laptop, I couldn't see it needing more than an hour or two to get them close with warm nights. Solar has a very nice advantage though: it will fully recharge batteries at end of trip. Yes half gallon gas per hour.

[PSW]

As to the question of which is best: Two six volts in series or two twelve volts parallel? I have had both and IMO two sixes will serve you better. Some people go battery nuts as to quality. I would just get a couple of deep cycle sixes and call it a day. The last ones I bought I got at Sams .

Paul

[jsw513]

tpi wrote:
In the desert you'll need the AC and the generator to do that. But that brings another thought-if you're running the AC half the time on generator, you really may not need solar at all. You can charge the batteries during the AC run time.

FWIW it is about $2. per hour for generator fuel in hot part of the day.

So, on average, about a half gallon of gas per hour? How quickly does the average generator recharge batteries?

[jsw513]

DiploStrat wrote:
My truck, Nedeke Luka does not have:

-- A generator, or,
-- Propane.

It does have:

-- Induction cooktop/convection microwave
-- Air conditioner
-- Fans

These are powered by:

-- 600w of solar
-- 250A of alternators

Charging:

-- 600Ah of AGM batteries

If I can do it, so can you. My favorite oracles are:

-- Handy Bob: Handy Bob and
-- AM Solar: AM Solar - the company that sold my solar kit.

You can read more here: DiploStrat

Not all of this will apply to your situation but it is possible to get much better solar/battery performance than many people realize.

And no, I don't plug in at campsites.

This sounds amazing! I could afford to potentially do something like this to avoid generator usage for A/C needs. Where/how do the alternators come into play?