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UPDATE! need recomendation for 200 watt solar and batteries

Hemi_Joel
Explorer
Explorer
Hi, I want to put 100 - 200 watts of solar on my arctic fox 1050. To keep the batteries up while I am dry camping. I have 2 group 31 batteries, and they are both shot. I only dry camp in 1 spot for 2 to 4 days before moving on. The main thing would be to avoid running the generator to keep the batteries up, and I have the generator to fall back on, so I don't want to overspend. I don't use much power, mostly lights (led), computer, a cpap machine all night, and sometimes the furnace. My 2 batteries are enough to get me through 1 night with the cpap and furnace running, or a few days without the furnace, but need to get charged.
I have searched on the subject, and there is so much info, it gets confusing.
Does someone have a recommendation or a link for what I should buy? I am looking for: easy to install, effective, not to expensive.

Thanks, Joel
2018 Eagle Cap 1163 triple slide, 400W solar, MPPT, on a 93 Dodge D350 Cummins, DTT 89 torque converter, big turbo, 3 extra main leafs, Rancho 9000s rear, Monroe gas magnums front, upper overloads removed, home made stableloads, bags.
58 REPLIES 58

ToyHauler
Explorer
Explorer
NinerBikes wrote:
ToyHauler wrote:
If it were me?
I would have bought one 24v 250+ watt panel and a good MPPT controller.wired up some 10ga tray cable and reaped the MPPT love.


But it wasn't you, it was Hemi Joel. 250w hardly makes MPPT useful over PWM.

Well Mr Ninerbikes.
Since I am feeling fashionably froggy tonight.
I will explain in detail the problems I see in the OP installation.

1. The wire is exposed and not uv protected. Which will lead to failure in the insulation as it is not rated for uv exposure.( Fire hazard)
2.The residential plastic junction box is not uv rated and will degrade exposed to the sun.

Not withstanding a physical inspection ?
That is all I can come up with at the moment
Keystone Raptor 3712TS
BigBlack F450 6.7

pianotuna
Nomad III
Nomad III
Hi Socal dmax,

Thanks for the enlightenment.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

pianotuna
Nomad III
Nomad III
Welcome to my confusion club. I'm a charter member!! *grin*

ToyHauler wrote:
Sorry for the confusion. ๐Ÿ™‚
My mistake.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

ToyHauler
Explorer
Explorer
Sorry for the confusion. ๐Ÿ™‚
My mistake.
Keystone Raptor 3712TS
BigBlack F450 6.7

pianotuna
Nomad III
Nomad III
Hi,

You misunderstand. If I did not have my existing inverter I would have a 24 or 48 volt battery bank. That has almost NADA to do with panel voltage which is just a matter of choosing an appropriate charge controller. However the biggest controller I'm aware of is the PT-100 with 100 amps of capacity. That limits the solar "farm" to 1200 watts. If you want more--then you get into the game of having more than one charge controller OR going to a higher voltage battery bank.

ToyHauler wrote:
pianotuna wrote:
Hi,

It would cost me a new inverter to move to 24 or 48 volts.

As it happens, the Magnum PT100 IS an MPPT unit, but that is not why I chose it. I chose it because it can handle 100 amps. It costs about $800. usd.

ToyHauler wrote:
24 volts is more efficient than 12 volt and mppt gives an advantage over pwm significantly over lower voltages all the way. Its a win win no matter what your preference.
So I would argue over your lower voltage preference

Your being cheap
The benefits you get from higher voltage and the benifits from the amperage you get from the controllers. negates the cost. IE your being a cheap ass at a deficiency.



I have the very same inverter as you and I run 24v panels.
I see higher charge amps using the 24v than I ever did with 12 volt with as many watts per panel bank. Almost double in fact.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

socal_dmax
Explorer
Explorer
Just saw this thread, haven't been around in a long time. I've installed about 12-13 RV solar panel systems, usually with a battery upgrade and inverter install, plus 2 yacht solar systems with inverters and batteries.

Here's a quick rundown of some of my thoughts, based on the above and posts in this thread.

If you're going to run 700 or 800 watts or more, then you need to look into the really good MPPT controllers like Outback, Midnite Solar, Morningstar, Rogue, Magnum, Xantrex, Victron, etc.

What I don't like about most of those is they're expensive, and most of them force you to buy a remote display to see what's up, at $100 or more. You could mount say 3x300w panels and use 3 Eco Worthy controllers, about 1/2 the price of any of the above.

In Hemi Joel's case, I agree with toyhauler, he could have bought 1 250 watt panel for $148 and a 20A Eco-worthy MPPT controller for $102, spent a couple of $$ on good cable and if he was parked facing south, he'd get about 14A peaks in the winter, probably 18A peaks in the summer. Not too bad for a $275 investment. So far, I've installed 10 Eco-worthy controllers (2 for myself, 2 customers are running dual controllers) and I'm very impressed with the speed it locks onto MPPT, the easy on screen menu allowing you to set all of the voltages in .1v increments, the gold plated contacts and all SMD internal construction with conformal coating. I have one right now with 410w of panels on it and it will put out 22A (110%) all day long and doesn't miss a beat.

I'd be very careful about using semi-flexible panels, they really aren't all that flexible, since they use the same silicon based solar cells as regular panels. A few brands (Solbian, Renogy, Kingsolar, HQST, Allpowers) use Sunpower cells, which are currently the most efficient cells on the market, an important feature with limited roof area like a boat or RV. But all of them, even the Sunpower cell versions, are prone to micro cracking from flexing, and overheating due to being a very dark surface and no cooling on the back if mounted flat on the roof. Renogy recently had a recall of all of their panels and added a thin aluminum panel on the back to dissipate heat, some of the owners who removed them reported scorched fiberglass underneath the cells. I'd be concerned the adhesive and rubber roof on an RV would be a lot easier to ignite.

The other issue is the "off brand" Chinese made panels are noted for producing considerably less than the advertised 100w/panel. A lot of boaters have removed the flexible panels and switched over to rigid panels and used them to make a bimini or cover.


I also agree with the GC batteries, I usually install 4 or 6 for my RV customers. Much cheaper and more power than most deep cycle batteries. Something to keep in mind, most people never get their batteries fully charged. I'd go to the mfr's website and look up the absorption voltage they recommend. It could be as high as 14.9 or 15v, if your controller and/or battery charger is adjustable, anything less than the recommended voltage isn't going to charge them up.

Toyhauler and I are both running enough solar power (he has 750w, I have 475w) that we were going into float mode by 10 or 1030 am, so we bought ice makers (he has 2 of them) to make ice all day and keep the solar charging a bit longer, keeping the batteries in absorption mode all day and crank out ice for drinks and coolers. I know a lot of people do an energy audit and budget and all that...

but there's no such thing as too much power, or too much ice!

ToyHauler
Explorer
Explorer
pianotuna wrote:
Hi,

It would cost me a new inverter to move to 24 or 48 volts.

As it happens, the Magnum PT100 IS an MPPT unit, but that is not why I chose it. I chose it because it can handle 100 amps. It costs about $800. usd.

ToyHauler wrote:
24 volts is more efficient than 12 volt and mppt gives an advantage over pwm significantly over lower voltages all the way. Its a win win no matter what your preference.
So I would argue over your lower voltage preference

Your being cheap
The benefits you get from higher voltage and the benifits from the amperage you get from the controllers. negates the cost. IE your being a cheap ass at a deficiency.



I have the very same inverter as you and I run 24v panels.
I see higher charge amps using the 24v than I ever did with 12 volt with as many watts per panel bank. Almost double in fact.
Keystone Raptor 3712TS
BigBlack F450 6.7

ToyHauler
Explorer
Explorer
Well if I was getting 1 250 watt panel on the cheap I would get a
http://www.eco-worthy.com/catalog/worthy-mppt-solar-charge-controller-12v24v-p-182.html and a panel from solar blvd.
In fact 350 watts laid flat is doable.
If I wanted more? another $100 controller would do the trick without breaking the bank.

The controller bucks the 24v down to charge 12v banks.
Just like the Morningstar.
Keystone Raptor 3712TS
BigBlack F450 6.7

pianotuna
Nomad III
Nomad III
Hi,

It would cost me a new inverter to move to 24 or 48 volts.

As it happens, the Magnum PT100 IS an MPPT unit, but that is not why I chose it. I chose it because it can handle 100 amps. It costs about $800. usd.

ToyHauler wrote:
24 volts is more efficient than 12 volt and mppt gives an advantage over pwm significantly over lower voltages all the way. Its a win win no matter what your preference.
So I would argue over your lower voltage preference

Your being cheap
The benefits you get from higher voltage and the benifits from the amperage you get from the controllers. negates the cost. IE your being a cheap ass at a deficiency.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

NinerBikes
Explorer
Explorer
ToyHauler wrote:
For how cheap current mppt controllers are now?
There is no excuse to buy a pwm controller


Examples and links?

ToyHauler
Explorer
Explorer
For how cheap current mppt controllers are now?
There is no excuse to buy a pwm controller
Keystone Raptor 3712TS
BigBlack F450 6.7

ToyHauler
Explorer
Explorer
24 volts is more efficient than 12 volt and mppt gives an advantage over pwm significantly over lower voltages all the way. Its a win win no matter what your preference.
So I would argue over your lower voltage preference

Your being cheap
The benefits you get from higher voltage and the benifits from the amperage you get from the controllers. negates the cost.
Keystone Raptor 3712TS
BigBlack F450 6.7

pianotuna
Nomad III
Nomad III
MPPT is for when you have run out of roof real estate or for when high voltage panels are needed for some reason. When panels were pricey MPPT made great sense.

Since I'm committed to 12 volt because of a pure sine wave inverter, if I upgrade I will go MPPT with the Magnum PT-100. That would allow me to install 1200 watts of solar. To do that would require a roof rack that goes above the air conditioner.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

NinerBikes
Explorer
Explorer
ToyHauler wrote:
If it were me?
I would have bought one 24v 250+ watt panel and a good MPPT controller.wired up some 10ga tray cable and reaped the MPPT love.


But it wasn't you, it was Hemi Joel. 250w hardly makes MPPT useful over PWM.