Batteries won't hold a charge as sun goes down, need advice on a solution!

Soconsani

Hey all, my partner and I are currently living on a raw piece of land in a sprinter van conversion, which we had a guy install the solar panels on and set us up with what batteries to buy, etc.
At first, when we were running led lights, charging our phones, using power tools, the solar didn't seem to have an issue and would charge to 14.4 during the day time according to the Blue Sky Energy controller (solar boost 3000i) that we bought. Last night the inverter sounded off and the batteries were at 11.1. Could not even plug our phones in.

I guess, I would love to know if the guy that set our solar up set it up to correct specs? And what we need to make our set up work long term. This is the only electricity we are depending on right now.

We are running 2 165watt 12 volt solar panels
2 centennial deep cycle 6 volt batteries, 224ah (whatever that means )
A xantrex prowatt sw 2000 watt inverter
And a distribution box for our a/c plugs and breakers.

What's wrong with our setup?

westbranch

what are the manufacturers settings  for those batteries and what is the CC set at?
After 3 hr of NO USE and also being charged, what is the battery voltage?
Do you know if you get through the ABSORB phase and into FLOAT?
What are the readouts in Volts and Amps while  charging?
Have you re-tightened ALL of the connections after moving the batteries?

more later...

Johann

What is your daily load in wh/watt hours.

Photowhit

We know very little about your system, but a system with 2 - 165 watt panels is not a very large system!

Figure normal output for 4 hours and storage and inverter use, you would normally get about enough energy to run 6-700 Watt Hours during sunny day's, I live on a similar system for quite a while, this would be a single energy efficient 10" fan over night, 2-3 hours of laptop and a couple hours of small LED TV and a 3-4 hours of a light...

If the panels are flat mounted our not in direct sun, you will get much or very much less energy. If you haven't had a run of cloudy days, look at how the sun hits your panels. 90 degrees? Have your loads changed? What have you added recently?

The xantrex prowatt sw 2000 watt inverter is spec'd to use less than 800MA with out a load, so figure 750 ma or .75 Amps at 12 volts or 9 watts per hour by it's self, with out powering anything...

Soconsani

We haven't actually tried not having a load on the batteries yet, I will try that in the morning for 3 hours.
It constantly says absorption and float at the same time during the day.
How would I find out what the manufacturers settings are on the batteries?

Ever since we got a small freezer, it's been really difficult to keep a charge.
The freezer uses 1.2 amps? And yes, the panels are flat mounted on the top of the van and the highest input is around 2pm when it says 17.5, volts I think? Today it topped at 12.8 and wouldn't get to 13. Right now it's at 11.5.

So the xantrex seems to take a lot of energy just on its own, is there a better suited pure sine wave inverter for this dinky system? I was also thinking of adding batteries, any suggestions there?

westbranch

the fact that it is showing Absorb  and  Float at the same time is an issue, it should be one or the other..
BTW BlueSky is older technology..  Is that 1.2 A AC or DC?  If AC that 1.2 =~12A DC...... and is it constant?  IF so that would kill those batteries in ~ a day +-....

Soconsani

I don't believe the 1.2 amps is constant - it shuts off for sure after it reaches cold enough temperature.

One thing that could have affected the system might have been the use of a large table saw? It didn't want to start and threw the inverter buzzer off.

I am keeping everything unplugged for 3 hours like you said. Right now it's in float and absorption. Does that mean the controller is messed up too?

Photowhit

Soconsani said:

I don't believe the 1.2 amps is constant - it shuts off for sure after it reaches cold enough temperature.

One thing that could have affected the system might have been the use of a large table saw? It didn't want to start and threw the inverter buzzer off.

I am keeping everything unplugged for 3 hours like you said. Right now it's in float and absorption. Does that mean the controller is messed up too?

It uses 1.2 amps AT 120 VOLTS AC! or 144 watts when running. Even with a duty cycle of 20% of the day or 5 hours of run time, you are exceeding your systems capacity with the freezer alone! 5 hours x 144 = 700+ watt hours.

Desert Rat

Soconsani said:

Ever since we got a small freezer, it's been really difficult to keep a charge.

There ya go.

Soconsani said:

 I was also thinking of adding batteries

Batteries store electricity, they do not produce electricity. Your loads are exceeding your production. You need to increase production or  decrease your loads.

Soconsani

Gotcha, so... Getting more panels might be the wisest fix to increase production?

is there any way to test the batteries to see if they are ruined?

Desert Rat

Normally the ideal way to size a solar electric system is to determine your daily loads and go from there. It sounds like your biggest load is the freezer. If it is AC, a Kill-A-Watt meter will tell you its actual daily usage.
Your batteries appear to be maintenance free, so it's not possible to check the specific gravity with a hydrometer. Checking the resting voltage will give a good indication, but they will have to be fully charged first. More info on battery testing at trojanbattery.com>Technical Support>Battery Maintenance>Testing.
Your present system is a good balance of array size to battery bank size, so ideally you would need more panels and more batteries.
And as Photowhit said, it's important to get the panels oriented correctly to maximize production.
It's not possible for the controller to be in Absorption and Float at the same time. If this is what it shows, something is wrong.

Johann

How long is your wire run from solar panel to charge controller?
What size of wire are you using for it?
How long is your wire run from charge controller to the battery and what size wire are you using for this run?