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48V system setting up outback charge controller.

Modul8

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I Inherited a PV system when I bought an off grid home in Panama.
I have :
8 X cr-205 6v flooded lead acid batteries, ( 48v total)
1x 60A outback charge controller,
1x outback inverter
1x outback mate remote
1x backup generator

Wondering if anyone can assist in helping me understand how the system works, for my own piece of mind, how to keep the batteries in good shape, and how to optimize it for long battery life and max Solar efficiency.
Lots of rainy days here in Panama, but also lots of blazing sun.
If anyone here has experience with this type of outback system on a 48v battery array, or knows the equipment well enough to help out, I'd love to hear from you.
 
That should be a good system. Outback makes good hardware. The batteries, I don't know if that brand is good or cheap.

Look up specifications for your batteries.
Read all the charge controller and inverter settings (charge profile, low-voltage disconnect, equalization cycle.)
Make sure a battery temperature sensor is used.

Use a good DMM to check voltage of each battery.
Hygrometer to check specific gravity of electrolyte.

Battery charging ideally is at a constant optimum current.
Power loads when there is surplus PV production. Minimize nighttime loads and cycling of battery for longest life.
I like PV panels with multiple orientations, catch morning & afternoon sun for more level production during the day.
Overpaneled, excess PV beyond what charge controller can process, helps with overcast days and clips for flat production during sunny days.
 
That should be a good system. Outback makes good hardware. The batteries, I don't know if that brand is good or cheap.

Look up specifications for your batteries.
Read all the charge controller and inverter settings (charge profile, low-voltage disconnect, equalization cycle.)
Make sure a battery temperature sensor is used.

Use a good DMM to check voltage of each battery.
Hygrometer to check specific gravity of electrolyte.

Battery charging ideally is at a constant optimum current.
Power loads when there is surplus PV production. Minimize nighttime loads and cycling of battery for longest life.
I like PV panels with multiple orientations, catch morning & afternoon sun for more level production during the day.
Overpaneled, excess PV beyond what charge controller can process, helps with overcast days and clips for flat production during sunny days.
The panels are unshaded by trees for most of the day , and are oriented flat, since we're at the equator.
No need for heat here, and AC is not on the menu. We have a small fridge that draws 100w continuously, and after that it's 1 or two overhead fans at night, a few led lights, and recharging phones/ laptop.
The batteries are crown brand , and I have a datasheet for them. It says to charge them at a rate between 20 and 50 Amps.
Here are some questions I am struggling with:
How do I know how full or empty (electrically) my batteries are? Is it a specific voltage range?
How do I decide when to turn on the generator on a cloudy day?
How much power is being generated on a cloudy, rainy day?
What does it mean when the charge controller is 'sleeping' on a cloudy day?
 
Well with the amount of power you are using I would set my charge controler to 59 v absorb witha a 2 hour absorb time
then watch your charger , I assume you have 230 AH at 48 volts so your watt input at 2 hours should be below 300 watt or at 200watts this will be very close to full charge .
Then check your SG and you should see 1.275 or there abouts if any of your cells are off 10 points or down to 1.265
I would raise the absorb time to 3 hours and the battery’s should equal out . in a few days or a week .
One your sg is good go back to 2 hour absorb .
You should get power on a cloudy day .
49 volts should be about 65% charged so it would be a good time to run the genarator .
I just never go down to 50% charged .
Your fm60 tells you the watts that are coming in in the main frame on the controler
Sleep mode is the unit powering down because of low power .
How much solar power do you have ?
You should not sleep on a cloudy day if you have enough solar on the roof .
Your inverter should charge @ 1800/ 1900 watts putting out max power but the charging #s can be Changed in the mate .
I would think you would need2 strings 3 300 watt panels so 1800 watts +- maybe less in your area
I have a outback 36x48v inverter with fm 80 charge controller 16 6v golf cart batteries and 4500 watts of solar .
Best thing you could do is keep your fingers off your settings buttons in the mate and charge controller un till you understand all the out back language or you could change settings and not be able to get them back .
you should check to see if you need a firmware up date .
( ALL ways turn on your fm 60 charge controller before you turn on the solar panels .)
most frigs only run half the time , so you should use 1200 watts a day about.
 
Equator, so longest average day throughout the year, and not short days like the rest of us get.
Flat means dirt more likely to accumulate. Maybe you will have to clean them. With our sloped they mostly get rinsed by rain.

If half the panels tilted toward 9:00 or 10:00 AM sun and half toward 3:00 or 4:00 PM sun, the peak wattage would be reduced but morning and afternoon would be increased, flatter curve. More total wattage of panels and more production possible with same charge controller.

At a particular temperature, after the batteries have been resting a few hours with neither charge nor discharge, voltage indicates state of charge.
Specific gravity measured with hygrometer accurately measures state of charge (maybe a few tricks about avoiding stratification.) Wear goggles and clothes you don't care about.
A system which measures current into and out of batteries, and resets itself to 100% under some conditions, can report state of charge.

My inverter/charger is the only DC connection, so it does that. If other DC coupled devices were connected, I could use a current shunt in series with the battery, and the inverter would measure that. You can get stand-alone battery monitors.

My 12kW of PV might produce 2kW with light overcast, 300W with heavy overcast.
You should be able to read charge current on the charge controller.
Some time when battery is low, read charge controller during Noontime sun, and see how power output compares to panel ratings.
You can also get a clamp DC ammeter to read PV string current, charge controller current, battery current.
 
The two wild cards here are that you didn't say how old those batteries were, nor how many watts of panels are charging them. A good rule of thumb for flooded lead-acid is that they like charging at about 1/8 of capacity. Since those are 205Ah batteries, 1/8C would be 205Ah/8 = 25.6A.

The largest amperage charging occurs at the lowest voltage, which in your system I think would be about 50V charging. With your controller set to charge a ~59V, starting charging will likely be around 50V. Since panels almost never put out more than 85% of their rated output, you should have at least (25.6A X 50V)/85% = 1505W of panels.

Definately follow the advice about monitoring specific gravity. It is the single best way to monitor a lead-acid battery. If all the cells are not in the 1.265-1.275 range, I would try equilizing them first, and it that does not improve SG, then start thinking about replacing the batteries in the not distant future.
 
Batteries were fresh in early June. Crown CR-205
There are 8 solar panels, a mix of two different sizes/ types. Not sure about the output yet. I have to find the name plates to verify the model.
Can you recommend a hygrometer?
 
Hygrometer is a simple glass tube with squeeze bulb and float. You can get them at auto stores.
Somebody mentioned checking where it reads with pure water. (or maybe that was a refractometer, which I'm not familiar with.)
 
Hygrometer is a simple glass tube with squeeze bulb and float. You can get them at auto stores.
Somebody mentioned checking where it reads with pure water. (or maybe that was a refractometer, which I'm not familiar with.)
The reason for that is that specific gravity changes with temperature, and on warm or cold days, the SG can give false reading. The best kind of hydrometer that's most accurate is the one's with temperature correction. I use this one.

If you can't find one with temperature correction, then use the method that Hedges mentions, and calibrate it to pure water first. Make sure you carefully rinse out any residual acid before attempting to check calibration.
 
Batteries were fresh in early June. Crown CR-205
There are 8 solar panels, a mix of two different sizes/ types. Not sure about the output yet. I have to find the name plates to verify the model.
Can you recommend a hygrometer?
That's excellent! Keep an eye on charging, and don't drain them past 50% and they should give you years of service. I would strive for less than 25% per day. My first set of batteries were Trojan T-105s and I passed those on to a neighbor after 5 years because I thought they still had enough life left to keep from turning them in.

See, please find the specs on those panels. The single best way to preserve the life of lead-acid batteries is to fully charge them each and every day. Keep them watered with purified water ONLY. Never use tap water.
 
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