Help Locating Power Drain

[aggie]

Our Morningstar controller is showing daily max output power as ranging between 2300-4600 watts for the past few weeks since we installed it. Early this morning, it displays max output power as 3340 watts, though nothing has run but a home router and a 400 watt refrigerator (converted chest freezer). What could be causing this? A flaky refrigerator? We've checked and reconnected wiring repeatedly. I'm talking out my ear, but could it be our modified sine wave inverter with grounded batteries? Thank you.

[Mike90250]

When the battery is low, and the sun is bright, the controller will supply lots of power to recharge the batteries.

Using a mod sine wave inverter will increase your fridge power consumption by 20% or more. And it's not safe to ground a mod sine inverter because of the way it can impose high voltage on the battery cables

[Sunking]

Batteries have to be recharged. My guess is you are in deficit charging which means you drain your batteries everyday and the solar cannot keep up.

[aggie]

Warm thank yous for your help, both of you.

When the battery is low, and the sun is bright, the controller will supply lots of power to recharge the batteries.

I was not clear. Here is Morningstar's definition: "Max.Output Power - the highest battery output power recorded for the day." We have 600 watts of modules, so numbers in the 3-4k range cannot be power to batteries, but must be power output by batteries.

Using a mod sine wave inverter will increase your fridge power consumption by 20% or more. And it's not safe to ground a mod sine inverter because of the way it can impose high voltage on the battery cables

We're planning on replacing the inverter, Is it safe to unground the batteries until we do?

Sunking, we know we're not charging our batteries optimally, but have increased controller absorption time, reconnected a loose wire from the array, and ordered more modules. My concern is what is stealing so much instantaneous power. We didn't buy a killawatt because a reviewer said his mod sine wave inverter fried it.

Thanks again.

[Sunking]

I was not clear. Here is Morningstar's definition: "Max.Output Power - the highest battery output power recorded for the day." We have 600 watts of modules, so numbers in the 3-4k range cannot be power to batteries, but must be power output by batteries.

Wrong, the controller has no clue where power is going. It can be going in the batteries or out to a load. You do not know the difference between power and energy.

A WATT is a unit of Power and Power is the Rate at which Energy is being either consumed or generated.

WATT HOUR is a unit of Energy of how much heat energy has been used or generated over a period of time.

Example say you have a 100 watt light bulb and want to iluminate it for 10 hours. How much Energy does it use.

Watt Hours = Watts x Hours

100 watts x 10 Hours = 1000 watt hours.

So your controller is telling you it generated 3000 to 4000 watt hours at a rate of 600 watts. All that means is it took 5 to 7 hours hours to generate that energy. The controller has no clue if that energy went into the batteries or loads. It went somewhere.

Sunking, we know we're not charging our batteries optimally, but have increased controller absorption time, reconnected a loose wire from the array, and ordered more modules. My concern is what is stealing so much instantaneous power.

Absorb time nothing to do with your problem.

All we can do is make educated guesses. Seeing how you do not understand energy my best guess is you are trying to use more energy than your system can generate. Think of it as money. You earn $100 per day, but spend $150 per day which means you are bankrupt and insolvent.

OK it is super easy to find what is using power. Turn things off. If you have everything turned off and only your batteries are connected and still using power, guess where the power is going? To your batteries.

[aggie]

Sorry for the delay. I didn't realize that I wasn't subscribed to email notifications.

After completing a firmware update at Morningstar's recommendation, the "Max output power watts" readings are reasonable, in the 450-550 w range for energy into the batteries. Problem solved.

I'm quoting Morningstar when I say "power in watts," or "instantaneous power in watts."

I increased absorb time because that's what the Rolls battery formula said would fully charge my batteries. However, I'm looking at how to implement https://www.solarpaneltalk.com/forum...tteries-part-2. You might see me posting again.

Thanks again!

[Sunking]

I increased absorb time because that's what the Rolls battery formula said would fully charge my batteries. However, I'm looking at how to implement https://www.solarpaneltalk.com/forum...tteries-part-2. You might see me posting again.

That does not mean your batteries are being recharged. Look at it like money. If it cost you $100/day to live, and you only make $50/day, guess what happens to you?

You turn into a Democrat and go on welfare because you failed math and economics in school. It is not your fault because schools quit teaching math and economics by design.