Help with my system please

[lkruper]

I have not had the ingredients installed yet. I am planning to test it all out in a few days. So what I am hearing now is that I need to upgrade the charge controller and get a few more panels after I decide how much I will be running off the system.
I HOPE to power a 125 watt tv, 38 watt dish network hopper (a few hours/day) , 6 watt modem (12 hours), 45 watt laptop, one 10 watt LED light.

Here is how you would calculate you needs:

125w tv X 4 hours +
38w dish hopper X 4 hours +
6w modem X 6 hours +
45w laptop X 6 hours +
10 watt LED X 12 hours
===============
500 +
152 +
36 +
270 +
120 =
=====
1078 wh / day

If you take your 100AH 24v battery down to 50% that leaves 50AH

1078 wh / 24v battery = 45 AH / day
But there is an inefficiency in the following:

Your inverter will be 80-90% efficient so
45 X 1/.8 =56 AH

Your big inverter also consumes power, the specs should show self-consume wattage.

You are a bit over 28%, not too bad.

Your panels and charge controller will need to supply:

56 AH X 1/ 0.86 panel inefficiency X 1 / .95 charge controller inefficiency = 69 AH
69 AH X 24v = 1656 Wh

From before your panels put out 408w

1656/408 = 4 hours

You say you have a marginal 4.5 hours but there is shade. Does that reduce the 4.5? You will need
5 hours to bulk charge + 2-4 hours for absorb.

You are light on charging, and don't forget your huge inverter is potentially a fire hazard.

Check my calcs

[thastinger]

I have not had the ingredients installed yet. I am planning to test it all out in a few days. So what I am hearing now is that I need to upgrade the charge controller and get a few more panels after I decide how much I will be running off the system.
I HOPE to power a 125 watt tv, 38 watt dish network hopper (a few hours/day) , 6 watt modem (12 hours), 45 watt laptop, one 10 watt LED light.

Just use the tool in the off-grid section, there have been countless that came here post install and found out the weren't anywhere near what they needed for a properly functioning system...load demand is the first calculation and a kill-a-watt meter helps with that.

[Aradia]

I have not had the ingredients installed yet. I am planning to test it all out in a few days. So what I am hearing now is that I need to upgrade the charge controller and get a few more panels after I decide how much I will be running off the system.
I HOPE to power a 125 watt tv, 38 watt dish network hopper (a few hours/day) , 6 watt modem (12 hours), 45 watt laptop, one 10 watt LED light.

[lkruper]

LKruper thank you for the response. Let me try to see if I understand what you are saying. I need to get some more batteries, I should wire in parallel with fuses and I do need a battery box. I could not understand some of what you were saying like what solar isolation means. Did I miss some of your points? If so can you dumb it down a bit for me please?
thank you so much for your help

You should not buy anything yet. You must first define your load. Decide what you want to run and how long. This will require some effort on your part, but it is critical to do so or you won't succeed. Secondly, before I forget, you do not need more batteries right now because at this point it does not look like your panels and charge controller are large enough for your batteries. Before we know this, you need to check with the manufacturer of your batteries.

Secondly, your inverter is too big for the batteries. This is a dangerous condition whereby you could try to power too much load which could not only damage your battery but also potentially start a fire.

Do you have this system already set up and are you running anything from it? If so, what and how long?

[Aradia]

A few observations, not necessarily what you have asked:

1) Your inverter is too big for your battery bank. A rule of thumb is Inverter Watts / AH <= 2. Your number is 15. Here is why: Your 1500w inverter can draw 63 AH @ 24v from your 100 AH 24v battery bank. If you take your battery down to 50%, it will take only 37 minutes. The potential discharge rate on your battery may be too high for even your sealed batteries, check the technical manual for that manufacturer.

2) Your panels put out, with no efficiency loss, 408W, which is 17 AH @ 24v. That is 0.17C, but with 86% efficiency, and even some more loss from your charger controller (95%) that could reduce your AH to 14 AH or less, which is only 0.14C. Some AGM batteries like Concorde specify that is one takes their batteries down to 50% DOD, that they should be charged at least 0.2C.

3) Your batteries will charge no faster than 3.5 to 4 hours in bulk and take at least another two hours in absorb which brings it to 5.5 or 6 hours. Most places don't have that kind of insolation in the winter and some not even in the summer.

Don't be fooled by my title Solar Fanatic Check my numbers, I have no real experience, but hope to soon and hopefully get my math skills up to snuff first.

LKruper thank you for the response. Let me try to see if I understand what you are saying. I need to get some more batteries, I should wire in parallel with fuses and I do need a battery box. I could not understand some of what you were saying like what solar isolation means. Did I miss some of your points? If so can you dumb it down a bit for me please?
thank you so much for your help

[lkruper]

The footnotes of your panels also read: During the first 8-10 weeks of operation, electrical output exceeds specified ratings. Power output may be higher by 15%, operating voltage may be higher by 11%
and operating current may be higher by 4%.

Also, I now see you say you get 4.5 hours of sun in your zone. Depending on where you get that number from, it may not really be equivalent to solar insolation. Your MPPT controller will handle getting the voltage to the right level with your panels in parallel. You will need fuses if you wire your panels in parallel.

Sealed batteries do have the potential to allow gases to escape. I have seen battery boxes recommended by AGM manufactures... I would read their manual for that.

Now I see that your charge controller is only rated at 15 amps. That is probably low for your AGM batteries, check the manual.

[lkruper]

Hello all,
I am new here and would like some advice about my new system
I have:
three 136 watt Unisolar flexible solar panels each voc 46.2-42.2 They are supposedly for either 12 or 24 systems. http://www.soldonsun.com/files/UNI-PVL136.pdf
two 100 ah 12 volt Ocean sealed lead acid deep cycle batteries to be wired in series for my
24 v 1500 watt inverter

I also have a Morningstar MPPT Sun Saver 15 charge controller. Max open circuit voltage 75 v Battery Voltage Range 7-36 volts
• Nominal Maximum Operating Power*
12 volt battery 200 Watts
24 volt battery 400 Watts

http://www.morningstarcorp.com/wp-content/uploads/2014/02/SSMPPT_ENG10_1111.pdf

My question is whether or not my charge controller is strong enough to wire the 3 panels in series and if that is even necessary. I get approximately 4.5 hours of sun in my zone however it is a bit shady part of the day due to some tall trees. I may get either a stronger charge controller and probably another battery in the future. Would I be able to get just as good battery charging by wiring the 3 panels in parallel in low light Winter conditions ? Also, do I need to vent my battery box for sealed lead acid batteries?
thank you in advance

A few observations, not necessarily what you have asked:

1) Your inverter is too big for your battery bank. A rule of thumb is Inverter Watts / AH <= 2. Your number is 15. Here is why: Your 1500w inverter can draw 63 AH @ 24v from your 100 AH 24v battery bank. If you take your battery down to 50%, it will take only 37 minutes. The potential discharge rate on your battery may be too high for even your sealed batteries, check the technical manual for that manufacturer.

2) Your panels put out, with no efficiency loss, 408W, which is 17 AH @ 24v. That is 0.17C, but with 86% efficiency, and even some more loss from your charger controller (95%) that could reduce your AH to 14 AH or less, which is only 0.14C. Some AGM batteries like Concorde specify that is one takes their batteries down to 50% DOD, that they should be charged at least 0.2C.

3) Your batteries will charge no faster than 3.5 to 4 hours in bulk and take at least another two hours in absorb which brings it to 5.5 or 6 hours. Most places don't have that kind of insolation in the winter and some not even in the summer.

Don't be fooled by my title Solar Fanatic Check my numbers, I have no real experience, but hope to soon and hopefully get my math skills up to snuff first.

[Aradia]

Hello all,
I am new here and would like some advice about my new system
I have:
three 136 watt Unisolar flexible solar panels each voc 46.2-42.2 They are supposedly for either 12 or 24 systems. http://www.soldonsun.com/files/UNI-PVL136.pdf
two 100 ah 12 volt Ocean sealed lead acid deep cycle batteries to be wired in series for my
24 v 1500 watt inverter

I also have a Morningstar MPPT Sun Saver 15 charge controller. Max open circuit voltage 75 v Battery Voltage Range 7-36 volts
• Nominal Maximum Operating Power*
12 volt battery 200 Watts
24 volt battery 400 Watts

http://www.morningstarcorp.com/wp-content/uploads/2014/02/SSMPPT_ENG10_1111.pdf

My question is whether or not my charge controller is strong enough to wire the 3 panels in series and if that is even necessary. I get approximately 4.5 hours of sun in my zone however it is a bit shady part of the day due to some tall trees. I may get either a stronger charge controller and probably another battery in the future. Would I be able to get just as good battery charging by wiring the 3 panels in parallel in low light Winter conditions ? Also, do I need to vent my battery box for sealed lead acid batteries?
thank you in advance