Most MPPT controllers want to see 1.5 to 2.5x battery voltage. The further you get from the battery voltage, the harder the MPPT works and heats from losses.
Too low, and you have trouble EQ the cells
Hunting cabin with air conditioning, it's florida for God's sake
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Can't edit last post, continued here
at that temp extreme it comes out overvoltage, plus , if I wire them 2 in series the Vmp is 75.2
that looks to be closer to the most efficient input voltage for the flexmax 60
thanks
daveLeave a comment:
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What is your recommendation on stringing these, I got a great deal on some GCL Solar panels , 325watt
the specs are Vmp 37.6
Imp 8.64
Voc 46
Isc 9.24
if I run 3 in series it puts me at 151 volts Voc @ 40-32Leave a comment:
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Determine max connected load that wil be on at the same time x 1.25
You want the Inverter or genny to be 75% loaded.Leave a comment:
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Oh boy, this gets interesting
I was reading the outback inverter specs for the VFXR3648A and noticed that when only pulling 500 watts from it, the efficiency is horrible.
It does not get to a good percentage until your pulling 1k from it.
That will kill my mini-split a/c draw of only 500watts idea
What do I need ? a much smaller inverter ?
ThanksLeave a comment:
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Yes, cheaper for a smaller generator. We currently run a diesel kubota setup at 9.5kw rating. It's not loud but we just want to get away from running it all the time. I do have sun electronics here and can get modules for 50 cents a watt. Already bought a new outback flexmax 60 for 350.00 new . Big expense is those damn batteries
If you don't want to run the 9500 watt diesel gen, then get a smaller one that barely supports your minimum loads and use that for most of your power. Or get a slightly larger one and charge a small bank periodically as SK mentioned.
If you want to get solar, they can extend the times that the generator doesn't run - and can extend the life of your batteries by keeping them at a high SOC (at least for lead acid.) But it's generally not worth it to try to cover 100% of an intermittent load with solar.
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If I can claim the 30% federal tax break it makes it a little bit easier, we are looking 4 peace and quite also, and 4-5 months the weather is nice enough to not need the air conditioner.
so my next thought is maybe set this up small now, just 4 led lights and small loads. I have found the 48volt mini-split air conditioners that look promising, maybe only pulling 4kv a night.
I see the tax credit is going away by 2020 thoughLeave a comment:
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Yes, cheaper for a smaller generator. We currently run a diesel kubota setup at 9.5kw rating. It's not loud but we just want to get away from running it all the time. I do have sun electronics here and can get modules for 50 cents a watt. Already bought a new outback flexmax 60 for 350.00 new . Big expense is those damn batteriesLeave a comment:
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If you cabin is often unoccupied, keep in mind thieves and vandals can spot a solar installation from miles away. A generator is easier to hide or take with you when you aren't there.
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Yes
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Thank you guys for this info, I really appreciate your time...also dont want to be buying this stuff twice as it is expensive
My thoughts on battery life is I will only be cycling them about 50-75 times a year. That gets me about 10+ years , No?
Also we will be running the generator a little also
Sunking, are your numbers rated at only a 20% discharge of the bank ?
Also, its costing us about 1200.00 a year to run that generator currently
Thanks
Dave
Last edited by wetsu151; 04-30-2018, 02:17 PM.Leave a comment:
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8 Kwh-day at 48 volts is a 830 AH battery. A 48 volt 830 AH battery requires 4000 watts of panels and an 80 Amp MPPT charger.Leave a comment:
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And you get to replace that battery bank in 3-5 years. especially in the Florida heat.Leave a comment:
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Yes, I have a kilo-watt meter and will test it this weekend, I can't believe how much the air conditioner is gonna cost us in battery bank cost . wow !!
thanks for the charge info, did not think of that.
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