Our under installation solar system for our Montana

[djgodden]

I haven't considered what load this system will be sustaining, I've simply done a bit of research (enough to be dangerous) and selected what I can afford thinking ahead to expansion. It may be much larger than my current needs but thought I'd post it to see what comments or suggestions ya'll would offer.

4 Renogy 12v 100 watt Monocrytalline panels into a Renogy Tracer 4210 40 Amp MPPT Charge Controller charging 4 Trojan T105?RE 225 Ah, 6v deep cycle batteries connected in series to produce 12v which are further connected to a Go Power GP-SW1500-12 1500-Watt Pure Sine Wave Inverter. As well as a remote Renogy MT-5 monitor.

I have to sit down and calculate amp hours to determine how long this would run my air conditioner. More out of curiosity than intending to run it.

[djgodden]

OK, looks like the overwhelming opinion was the 1500W inverter was insufficient given hair driers, microwaves, convection, etc... So, I returned it and have the 3000W. No, I'm, not going to run the A/C, it was me being curious.

[rjsurfer]

I have an identical solar/battery setup except I have 700 watts of solar and there is no way I could run my rooftop AC.

I'm lucky if I get 15 to 20 minutes on my 1,500 watt microwave without going into low voltage shutdown.

You may have the solar and battery guts to run it if you go by the specifications for the individual components but that low voltage (usually 11.5) shutdown of the inverter will bit you in the ass every time.

Ron W.

[pianotuna]

Hi,

That depends--my microwave draws 1591 watts.

zb39 wrote:
1500 should run your microwave also.

[zb39]

1500 should run your microwave also.

[pianotuna]

2oldman,

two words

hair drier.

*grin*

[2oldman]

djgodden wrote:
Meaning a TV for a while, BlueRay, charge phones, use a computer, etc.

Then you don't need a 1500w inverter.

[djgodden]

Thanks for all the replies. As I indicated, I don't really intend to run the AC but was curious if it would run at all or if so, for how long. Looks like a beefier inverter would be needed as well as more batteries. Which is fine, I expect my setup to be able to sustain me easily for "normal" use. Meaning a TV for a while, BlueRay, charge phones, use a computer, etc.

[lasttruck]

djgodden wrote:
I haven't considered what load this system will be sustaining, I've simply done a bit of research (enough to be dangerous) and selected what I can afford thinking ahead to expansion. It may be much larger than my current needs but thought I'd post it to see what comments or suggestions ya'll would offer.

4 Renogy 12v 100 watt Monocrytalline panels into a Renogy Tracer 4210 40 Amp MPPT Charge Controller charging 4 Trojan T105?RE 225 Ah, 6v deep cycle batteries connected in series to produce 12v which are further connected to a Go Power GP-SW1500-12 1500-Watt Pure Sine Wave Inverter. As well as a remote Renogy MT-5 monitor.

I have to sit down and calculate amp hours to determine how long this would run my air conditioner. More out of curiosity than intending to run it.

Have the Renogy panels, MPPT and monitor like you, but am using Costco GC2 batteries and a Samlex inverter. Panels are wired series/parallel as are the batteries.

Just for kicks, I plugged in a 5200btu window AC and ran it for a couple of hours with direct, overhead bright sunshine. After two hours, I had a 8% net battery bank loss per the Trimetric battery monitor.

I am not able to remember if I had the AC set to high or low cool, but it was sitting outside, in the shade and did not cycle off.

An option, but only in full, overhead sun for a short period.

[time2roll]

If you are getting MPPT you may as well save money on panels and get 24v models. Easier to mount 2 large than four small. Run in series to simplify the wiring.

24v panels, 65 cents per watt

[pianotuna]

Hi John,

I should have qualified that and said "at least 8%, under most conditions".

[full_mosey]

pianotuna wrote:
Hi MPPT offers 8% improvement in solar harvest with nominal 12 volt panels.

ewarnerusa wrote:
Does MPPT offer any advantage with 12V panels? I thought that it did not.
I don't think that inverter could start the air conditioner compressor.

Maybe, if there is such a thing as a typical 12V nominal panel.

Example: I have a 130W(19.6V * 6.44A) mono panel with 7.44A ISC.

PWM = 107W / 14.4V = 7.44A.
MPPT = 130W / 14.4V = 9A.

That is a 23W advantage for MPPT, or 23/107 = 21.5%.

HTH;
John

[pianotuna]

Hi Scrub,

The real answer is "it depends".

I serviced 875 amp-hours of 12 volt batteries with 256 watts of solar. To do so I used two banks with switching. I got 6 years of life from one set of three and 10 years from one set of four.

For a part time rv'er, so long as there is 60 watts of solar per 100 amp-hours the battery bank can be equalized. There is not much point from a battery charging point of view in having more than 150 watts per 100 amp-hours as the charge acceptance rate for flooded lead acid batteries at 85% state of charge is about 12.5 amps (i.e. 150 watts).

What IS important is adjustable voltage set points.

For a full timer an energy audit will be a necessary process to find the wattage needed.

scrubjaysnest wrote:
Your 400 watts of solar is a perfect match to 2 105's in full sun. But for, four most likely you won't get the max life out of the batteries. To balance the two battery banks your wiring will need to be large and carefully done.
Per Trojan c/10 or 22.5 amps per bank is preferred. A bank is 2 6 volt batteries in series.

[pianotuna]

Hi MPPT offers 8% improvement in solar harvest with nominal 12 volt panels.

ewarnerusa wrote:
Does MPPT offer any advantage with 12V panels? I thought that it did not.
I don't think that inverter could start the air conditioner compressor.

[scrubjaysnest]

djgodden wrote:
I haven't considered what load this system will be sustaining, I've simply done a bit of research (enough to be dangerous) and selected what I can afford thinking ahead to expansion. It may be much larger than my current needs but thought I'd post it to see what comments or suggestions ya'll would offer.

4 Renogy 12v 100 watt Monocrytalline panels into a Renogy Tracer 4210 40 Amp MPPT Charge Controller charging 4 Trojan T105?RE 225 Ah, 6v deep cycle batteries connected in series to produce 12v which are further connected to a Go Power GP-SW1500-12 1500-Watt Pure Sine Wave Inverter. As well as a remote Renogy MT-5 monitor.

I have to sit down and calculate amp hours to determine how long this would run my air conditioner. More out of curiosity than intending to run it.

Since it takes closer to 3000 watts to start the standard A/C from a generator and then sometimes not. You can forget running with a 1500 watt inverter.
Your 400 watts of solar is a perfect match to 2 105's in full sun. But for, four most likely you won't get the max life out of the batteries. To balance the two battery banks your wiring will need to be large and carefully done.
Per Trojan c/10 or 22.5 amps per bank is preferred. A bank is 2 6 volt batteries in series.