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1Longbow · 09-21-2021, 04:58 PM

We have a 2014 Wind River and I'm running 2 12 volt deep cycle batteries. We do a lot of dry camping,and thinking about using a suitcase type solar panel,to keep the batteries charged. for those of you that have done this,can you tell me what is involved,or perhaps show a picture of you set up. Thank you for any info

Marine359 · 09-21-2021, 05:09 PM

Quote:

Originally Posted by 1Longbow

We have a 2014 Wind River and I'm running 2 12 volt deep cycle batteries. We do a lot of dry camping,and thinking about using a suitcase type solar panel,to keep the batteries charged. for those of you that have done this,can you tell me what is involved,or perhaps show a picture of you set up. Thank you for any info

I recommend that if you want practical solar that you mount 300w on the roof. We tried to get by with a 120w portable panel, but found that, we were on the go away from our TT often enough, that we couldn’t get enough daily wattage from our panel because we had to pack it away when we left our campsite. We have a 120w high efficiency Bi-fold soft panel and installed an SAE solar port In Our sidewall connected to a 75/15 mppt controller. It’s simply not enough for sustained boondocking.

SteveJ. · 09-21-2021, 05:29 PM

What other people do may or may not be close to your situation.

Do you have a shunt based battery monitor? If not get one as it will help immensely in boondocking and/or solar situations.

Once you have that monitor you can get an idea of how much power you use per day, critical info for sizing the setup.

Our setup, we use 25 to 100 amp hours per 24 hours depending mostly on the weather.

Two 120 watt EcoWorthy suitcase units.
Victron SmartSolar 100/30 controller with wireless remote voltage and temperature sensing.
This battery monitor:
https://amazon.com/gp/product/B0824X...?ie=UTF8&psc=1
50" of 12 gauge wire.

The controller can handle one or two more sets of panels if needed. Ok so far with an LP fridge. The expansion would be required with a 12 volt high efficiency fridge. A standard residential fridge would require more solar than I can easily/cheaply expand to. I would also have to expand the battery bank as I only have two group 31 batteries.

Note. I changed up the suitcase wiring to put each set in series, doubling the voltage and cutting the current in half. I did this because the higher voltage really helps the system perform quite a bit better on marginal solar days and I can use thinner supply wire.

I'm all in for about $600 including a cheap chain for security. I'm usually into float charging sometime in the afternoon or late morning, depending.

If you don't want to jump the voltage up you will need thicker wire, at least 10 gauge, more likely 8, especially if you want a longer cord to the panels. I have a 50' installed to a panelt with a 25' extension if needed.

If you are just going with nominal 12 volt panels(higher voltage highly recommended) an MPPT charge controller may be a bit of overkill in a small system and a much cheaper PWM controller may be the ticket.

Again, install the battery monitor and get an idea of how much power that needs to be replaced each day, then you/we can help with more specifics insted of doing "precision guesswork".

SteveJ. · 09-21-2021, 05:51 PM

Quote:

Originally Posted by Marine359

I recommend that if you want practical solar that you mount 300w on the roof. We tried to get by with a 120w portable panel, but found that, we were on the go away from our TT often enough, that we couldn’t get enough daily wattage from our panel because we had to pack it away when we left our campsite. We have a 120w high efficiency Bi-fold soft panel and installed an SAE solar port In Our sidewall connected to a 75/15 mppt controller. It’s simply not enough for sustained boondocking.

I can see your issues and reasoning for the 300 on the roof. No set up/ take down at the camp site is nice. An issue that I have with that way of doing things versus portables is you have to park in the sun to collect solar. For some folks that's OK, for our style it is almost always not.

In almost six years of camping mostly at public campgrounds or boondocking the $25 cheap chain with small combo locks has been enough security that I leave the panels out when gone for the day, which is almost always. Never an issue. Even if they do get boosted they are not all that much to get replaced.

In general, portable panels will yield 20 to perhaps 30% or more power due to sun angles, everything else(shading for sure) being equal. It can and will likely mean one less panel to buy.

There are a lot of different ways to do the solar thing. Different strokes for different folks. No one way is better for all of us. It's just nice not having to run a noisy, stinky, expensive to run generator when for less than a grand one can have solar and perpetual power, at least when the sun shines. We can go 2-4 dark cloudy days before doing the genny thing. The higher series voltage and the MPPT controller helps get some charging even on cloudy days.

Marine359 · 09-21-2021, 06:11 PM

Steve,
You’ve just hit the nail on the head by pointing out that you have a lp/12v fridge. That’s the wild card. If you have a 12v only compressor fridge, you simply cannot boondock on less than 50-75ah/day. We’ve been boondocking for a year now with a 12v fridge, so we think our data are pretty accurate. Yes everyone’s needs are different, but the OP’s needs are dependent on battery type, amp/hrs of bank, and fridge type. We should all advise OP to choose components that match his camping style (how many consecutive boondocking days), and budget. You cannot use chains or cables to secure a soft folding panel.

Cable length doesn’t matter much if you run 10 gauge from the panel to a mppt controller mounted near the battery. Voltage drop will be minimal. We use a 30ft cable. No measurable drop. IMHO, there is absolutely no reason to opt for a PWM controller over MPPT. Cost is not much different, and performance is substantially different.

Agree on shunt monitor. It’s an imperative. However, you can get by without it if you get a mppt solar controller and it’s your primary means of charging. I love our Victron Smartshunt. However, The Victron controllers will give you an accurate reading of battery voltage.

My final comment is: if there’s no sun there’s no solar charging no matter how many solar panels you have. If you live east of the Mississippi, get a small generator.

Marine359 · 09-21-2021, 06:22 PM

Ah,
Steve, looks like you live on west coast. If so, you’re absolutely right on almost everything. If you live on east coast, not so much. It’s been a wet spring/summer here. Sun less than 50%. Would send you west coasters water if I could.
Cheers.

Bobby F · 09-21-2021, 07:00 PM

Just something to consider:

I knew two RV's full of people who had their portable ground-placed solar panels walk away last year at Quartzsite.

They left them out all of the time, day and night, gone or present.

Solar panels at a flea market bring good money.

Vintage465 · 09-21-2021, 07:12 PM

I run 450w on the roof, gathered in a combiner box. Then #4 conductor to a PWM(because that's what I had)controller in the pass thru. Then #2 conductor to the 4-6 volt batteries. Never, ever looking for more power. Always charged back to full by 11:00-11:59 A.M. No tilting, no apologies, it just works great. Some day I'll boost for an MPPT and a Victron 712 and a shunt. It is the best way, but at the time I just wanted to put the money in the conductor and such.

Vintage465 · 09-22-2021, 06:01 AM

Quote:

Originally Posted by Vintage465

I run 450w on the roof, gathered in a combiner box. Then #4 conductor to a PWM(because that's what I had)controller in the pass thru. Then #2 conductor to the 4-6 volt batteries. Never, ever looking for more power. Always charged back to full by 11:00-11:59 A.M. No tilting, no apologies, it just works great. Some day I'll boost for an MPPT and a Victron 712 and a shunt. It is the best way, but at the time I just wanted to put the money in the conductor and such.

Quoting myself here! What I meant by "It's the best way"....is the MPPT and the Victron 712 and a shunt is the best way. But at the time of my installation I knew I'd be able to do that anytime in the future but at the time of the install I wanted to focus on getting good, large conductors installed.

SteveJ. · 09-22-2021, 06:28 AM

Quote:

Originally Posted by Marine359

Ah,
Steve, looks like you live on west coast. If so, you’re absolutely right on almost everything. If you live on east coast, not so much. It’s been a wet spring/summer here. Sun less than 50%. Would send you west coasters water if I could.
Cheers.

We live in central Flowruduh. Most camping is in the west with some in MN.

Our old solar system was 150 watts on a Roadtrek class B through a PWM controller. The MPPT unit on our current coach is a whole bunch better at providing a charge in marginal conditions, I think mostly due to our 2s2p panel configuration. The resulting higher voltage to controller is quite helpful. On brighter cloudy days we get a surprising amount of charging that would not have happened with a PWM controller at a nominal 12 volts.

Agreed, the LP fridge helps immensely. However, I'm leaning toward a 12 volt fridge if a replacement is needed. The Dometic DM2862 is right on the edge when it's into the upper 90's.