Need some more intelligent help then I have

[Old Tom]

Have 3es 240w 24v panels to a 60a controller and additional 3ea 240 w 24v panels to 60a controller both to 5 lead deep cycle 100 ah batts first controller to batt on # 1 batt second controller to #3 batt out of this to a 3000w inverter hooked to #5 batt
Will not run a small 800w window a/c unit for more than 2-3 hrs
Live by death valley so sun is not the prob
Ideas??????

 

[Mattb4]

Are your batteries new? How are the batteries connected? Are the connections tight? Have you done any load testing of your a/c unit? What does your charge controllers show for wattage when a/c is running?

I would think that the solar panels would provide adequate wattage in full sun to run your a/c even without batteries. So something is limiting the setup. Go through and double check voltages and outputs.

 

[Old Tom]

Are your batteries new? How are the batteries connected? Are the connections tight? Have you done any load testing of your a/c unit? What does your charge controllers show for wattage when a/c is running?

I would think that the solar panels would provide adequate wattage in full sun to run your a/c even without batteries. So something is limiting the setup. Go through and double check voltages and outputs.

Batts are new. Parallel for 12v. Amp load at ac unit is 7.3
Controllers both show apx 325 +.- on average

 

[Mattb4]

So a/c is pulling 7.3 X 120 = 876 watts ( assuming the voltage is correct) Your charge controllers are showing 325 watts each so that is 650 watts The draw of your a/c ( I assume nothing else is being fed) plus 5 to 20% used to power inverter is higher than the panels are delivering. Thus your batteries are making up the difference. If you are using 360 watts from your 12 volt battery that would be 30 amps. You should be able to check the battery amp draw with a meter if you have one. Check the cable going to the inverter.

The big problem I can see is you are not developing enough watts from your solar panels.

 

[Old Tom]

Ok I'll do some cking
Appreciate your reply
117 F today so I'll get back to you later with more info
Thx

 

[efficientPV]

Your system is upside down, not enough panels for your battery or AC. Unless you want to run AC once a week. The good news is you have lots of sun. That also means that the panels will be very hot and produce less than 70% of what they are rated for.

 

[Old Tom]

Would it do to add more panels or would they overheat the controllers they are both makeskyblue 60a

 

[Mattb4]

Unless I am misreading your OP you have 1440 watts worth of panels. At 75% that would be around 1080 watts you could expect to get full sun. I do not see that as under paneled for your 5 batteries. I do wonder why you are only getting 325 watts per 720 watt string. Though you should watch the watts being delivered over several hours during the day.

In terms of amount of panels you can connect per SC. Follow the voltage recommendations in your SCC manual. Higher voltage more watts you can connect.

 

[Supervstech]

Batts are new. Parallel for 12v. Amp load at ac unit is 7.3
Controllers both show apx 325 +.- on average

This needs to be addressed… why are you only getting 325W per controller? Your setup should get 720W… each. How are the panels mounted? How are they wired? What controller are you using?