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Solar help... Mppt or PWM

lawrosa
Explorer
Explorer
Hi.. I recently got a new solar panel from somewhere... fell off truck... lol




I know mppt is the way to go im mysituation but am asking for advice...


panel 250 watts
volts 30v.


What would you do with this residential panel?
\Someone told me the panel can produce up to 20 amps//



Please guide me as I need help in this area. I can take pics if needed...

Batterys are two 24 group 75 ah .
Mike L ... N.J.

2006 Silverado ext cab long bed. 3:42 rear. LM7 5.3 motor. 300 hp 350 ft lbs torgue @ 4000 rpms
2018 coachmen Catalina sbx 261bh
140 REPLIES 140

pianotuna
Nomad III
Nomad III
Hi,

I would never have a portable solar system unless it was either a fold up or roll up type. Install it.

I probably would not even allow for tilting the panel. After all, are you going to deploy the panel at 5 a.m? (I like to sleep in).
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.

lawrosa
Explorer
Explorer
Eco is missing on this Abs stage, you can set it 14,8 (or whatever it says in battery manual), but it lasts mere seconds unless you are watching it and changing settings on the controller manually. This is one of the things that I don't like about it, and there are few others. But you won't find anything both cheaper and better.


What do you mean here?

The eco and morningstar I read have adjustable parameters.


15A Morningstar model will exceed the limit occasionally , though unlikely will go up in smoke unless you are at high elevations. It might, but not likely.


I dont want something to go up in smoke..

Does my panel exceed the morningstars specs?
Mike L ... N.J.

2006 Silverado ext cab long bed. 3:42 rear. LM7 5.3 motor. 300 hp 350 ft lbs torgue @ 4000 rpms
2018 coachmen Catalina sbx 261bh

lawrosa
Explorer
Explorer
I dont think I want to hook the solar right to the batterys.. Dont sound line a good idea..

Here is the panel.. Yeah its a bit large. I may put it on the roof.. I have room, but I wonder what happens if its in the shade..

I tested the volts at the leads. Showed 35volts and it was no sun and cloudy. Is this correct?






Mike L ... N.J.

2006 Silverado ext cab long bed. 3:42 rear. LM7 5.3 motor. 300 hp 350 ft lbs torgue @ 4000 rpms
2018 coachmen Catalina sbx 261bh

red31
Explorer
Explorer
lawrosa wrote:


I am looking to do this on the cheap.



connect panel directly to battery, monitor battery voltage, disconnect when battery voltage is to your liking.

Almot
Explorer III
Explorer III
lawrosa wrote:
Im going to set it up on a stand and move it around to follow the sun..

If you are glutton for punishment. 250W panel weighs ~45 lbs and the size is awkward, 65" x 40". I have 2 of them on the roof. I would imagine it on a stand near shore cabin, but not carrying it in a truck and setting up every day.
lawrosa wrote:

The morningstar looks nice but is only a 15 amp model while that chinese unit is 20 amps..

As mentioned by many here, Morningstar has plenty of features, most of them I consider necessary for proper charging. Eco is very basic. You get what you pay for. 15A Morningstar model will exceed the limit occasionally , though unlikely will go up in smoke unless you are at high elevations. It might, but not likely.
lawrosa wrote:

Are there any other models to consider?

I am looking to do this on the cheap.


Go with Eco then. I doubt you'll find anything cheaper that also wouldn't be worse.

About 14.8V mentioned earlier - refer to YOUR battery manual to set voltages, including 14-something Absorption point. There can't be any "consensus" in these matters, every battery is different.

Eco is missing on this Abs stage, you can set it 14,8 (or whatever it says in battery manual), but it lasts mere seconds unless you are watching it and changing settings on the controller manually. This is one of the things that I don't like about it, and there are few others. But you won't find anything both cheaper and better.

JiminDenver
Explorer
Explorer
I have a larger Morningstar MPPT controller for my main system. It is much more customizible than the Eco-w. In this case it wouldbe a trade off of max amps vs custom settings.

Tracer makes a 20 amp for under $200 that does more than the Eco-w.

Btw. In 4 years of using the Eco-w I have never heard a complaint of failure with the Eco-w here or any of the places I discuss it.
2011 GulfStream Amerilite 25BH
2003 Ford Expedition with 435w tilting portable/ TS-MPPT-45
750w solar , TS-MPPT-60 on the trailer
675 Ah bank, Trip-lite 1250fc inverter
Sportsman 2200w inverter generator

CA_Traveler
Explorer III
Explorer III
Morningstar has an excellent reputation and should be considered. However the Ecoworthy can be a good starting point.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob

socal_dmax
Explorer
Explorer
westend wrote:
The morning star is 154 while the eco is 110 on amazon..

Get the Morningstar, it will be the best $44 you spend on the system.

BTW, that is the lowest price I've seen on the small Morningstar MPPT controller. I paid $200 for mine.


Just curious, why do you feel that way?

westend
Explorer
Explorer
The morning star is 154 while the eco is 110 on amazon..

Get the Morningstar, it will be the best $44 you spend on the system.

BTW, that is the lowest price I've seen on the small Morningstar MPPT controller. I paid $200 for mine.
'03 F-250 4x4 CC
'71 Starcraft Wanderstar -- The Cowboy/Hilton

CA_Traveler
Explorer III
Explorer III
Go with the Ecoworthy or used. What you'll learn for any future solar will be invaluable.

Good to save a pic of the panel label on your PC for future reference.

BTW Please send that truck out my way. :B
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob

lawrosa
Explorer
Explorer
Im going to set it up on a stand and move it around to follow the sun.. The morningstar looks nice but is only a 15 amp model while that chinese unit is 20 amps..

Are there any other models to consider?

I am looking to do this on the cheap.

The morning star is 154 while the eco is 110 on amazon..
Mike L ... N.J.

2006 Silverado ext cab long bed. 3:42 rear. LM7 5.3 motor. 300 hp 350 ft lbs torgue @ 4000 rpms
2018 coachmen Catalina sbx 261bh

CA_Traveler
Explorer III
Explorer III
OP,

If you are not aware we're discussing those max amps at noonish. Flat mounted or fixed tilt you don't get that all day long. A fully tracked panel does much better of course but they and generally not practical for a RV.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob

JiminDenver
Explorer
Explorer
Last week I dug a 230w panel out of a snow bank and set it in direct sun. Altitude AND freezing cold resulted in over 17a when I normally see 15a from the panel. The same conditions had my 220w jump to over 40 Voc briefly and hold at 38v working. Well above it's rating.

Careful going over those passes in the winter time. lol
2011 GulfStream Amerilite 25BH
2003 Ford Expedition with 435w tilting portable/ TS-MPPT-45
750w solar , TS-MPPT-60 on the trailer
675 Ah bank, Trip-lite 1250fc inverter
Sportsman 2200w inverter generator

CA_Traveler
Explorer III
Explorer III
JiminDenver wrote:
The max I have seen from my 250w panels is 18.5a on MPPT. On PWM they will put out 10+ amp at altitudes we camp at.
Good information. 250/14.8 = 16.9A for bulk flooded battery charging. No reason IMHO to consider amps at 12.0V.

So 16.9A for nominal conditions and the panel pointed directly at the sun. More amps are available with lower temperatures, clearer sky, etc. which Jim in CO implies.
2009 Holiday Rambler 42' Scepter with ISL 400 Cummins
750 Watts Solar Morningstar MPPT 60 Controller
2014 Grand Cherokee Overland

Bob

JiminDenver
Explorer
Explorer
I have used the Eco-w controllers for years. a good combo with your panel as long as the feature set meets yosur needs. The biggest thing is it does not have temp compensation nor voltage sense.

The max I have seen from my 250w panels is 18.5a on MPPT. On PWM they will put out 10+ amp at altitudes we camp at.
2011 GulfStream Amerilite 25BH
2003 Ford Expedition with 435w tilting portable/ TS-MPPT-45
750w solar , TS-MPPT-60 on the trailer
675 Ah bank, Trip-lite 1250fc inverter
Sportsman 2200w inverter generator