dumb question about battery use & charge

[Endeavour]

I'm in the middle of my solar design and had a thought which confused me;

If I have a bank of 12v batteries supplying charge to the RV (lights @ 12v and then outlets and fridge @ 110v via an inverter)
The fridge is obviously meant to be running 24/7 - or more realistically: 24 hours a day for 3-5 days we are up at the trailer.

So here is where the dumb question comes in. With solar panels and a charge controller, how is it recharging the batteries at the same time as providing a power source to the fridge?

[Logan5]

If your producing 100 watts and using 100 watts, no charge is going to the batteries. If you produce 100 watts and are using 50 watts, then 50 watts is going to the battery. If you produce 100 watt's but are pulling 150 watts then you are pulling 50 watts from your battery.

[Garrett]

Refrigerators typically don't run 24/7, rather they cycle on and off throughout the day; that's the thermostats job. If you don't have a Kill-A-Watt I'd suggest getting one, they come in very handy.

[SunEagle]

Refrigerators typically don't run 24/7, rather they cycle on and off throughout the day; that's the thermostats job. If you don't have a Kill-A-Watt I'd suggest getting one, they come in very handy.

Do you mean the light inside goes out when you close the door?

[J.P.M.]

Do you mean the light inside goes out when you close the door?

In the spirt of Godel's Incompleteness Theorem, we'll never know.

[Garrett]

Do you mean the light inside goes out when you close the door?

At the age of 10 I can say it does indeed turn off.

[J.P.M.]

At the age of 10 I can say it does indeed turn off.

Were you inside an operating fridge with the door closed ? Possible I suppose., but probably not to be recommended.

[Garrett]

Were you inside an operating fridge with the door closed ? Possible I suppose., but probably not to be recommended.

Yep, it was my grandfathers bat fridge at the lake house, door was closed and my brother was outside; we took turns. One might think it was stupid and wrong, but we knew what we were doing. Flying a kite in the thunderstorm didn't turn out too bad for us.

Anyways, enough chatter, back on topic or this this thread will get deleted.

[Sunking]

So here is where the dumb question comes in. With solar panels and a charge controller, how is it recharging the batteries at the same time as providing a power source to the fridge?

Yep it is a dumb question. Same way you get power when it is dark, it is stored away in the battery. Say your fridge uses 100 watts and runs 24 x 7. Means you use 2400 watt hours. That means you must generate 3600 watt hours during the day to replace the 2400 you use. With only a 4 Sun Hour day means you need 900 watt solar panels. For those four hours of Sun you have to recharge the batteries and supply the load with power.

Think of it like your car So here is your dumb question. How can a car drive without a gas pump attached supplying gas? Duh that is what you have a tank for. You pump in 10 gallons in 1 minute, and the engine runs 6 hours on the highway before you have to refill.

[Endeavour]

thanks for the belittling response sunking. Glad you're such an expert that you've never asked a basic question before.
Way to encourage new people to ask questions

(even though you haven't actually explained anything on the process of power regulation and distribution)

[J.P.M.]

thanks for the belittling response sunking. Glad you're such an expert that you've never asked a basic question before.
Way to encourage new people to ask questions

(even though you haven't actually explained anything on the process of power regulation and distribution)

The way I leaned it, the only dumb question was the not asked others after exhausting all the ways to find the answer on my own. Assuming you did that, to the degree that premise about self learning is valid, I'd suggest your question was not dumb.

SK can sure respond for himself, but FWIW, I saw no belittlement in his response. Quite the contrary. Looks to me, at worst, he was not necessarily agreeing with your statement (BTW -) that you posed a dumb question, as much as identifying what you called dumb and using an analogy to identify or perhaps frame what looks to me like the core of your question in a slightly different way.

More FWIW, looks to me that it was a pretty socratic way to help you help yourself.

I also didn't see any reference at all made to or about you personally, either good or bad.

I'm also quite sure SK could explain enough about what you call the process of power regulation and distribution to the point your ears would water, but my guess is that wouldn't answer your question as much as it would probably result in SK getting accused of arrogantly talking down to you and another accusation of belittlement. from you.

Take what you may want of the above. Scrap the rest.

[Endeavour]

lets take the car analogy then - obviously you don't drive connected to the gas pump (duh!) , but neither are you running the engine when filling up with gas. It's an either/or situation. You are either refilling and not powering the engine (appliances) or you are driving around and not able to refill (recharge)

My question is rooted in the management of recharging when you are running things off the batteries. there is always going to be some nominal draw on the power store, especially when going through inverter and converters to the 12v lights, 110v fridge & water heater both of which activates when needed.

so the charge controller is recharging batteries when it has solar power, but what happens to the output (appliances) during this process, are you basically opening up a larger circuit?

[J.P.M.]

lets take the car analogy then - obviously you don't drive connected to the gas pump (duh!) , but neither are you running the engine when filling up with gas. It's an either/or situation. You are either refilling and not powering the engine (appliances) or you are driving around and not able to refill (recharge)

My question is rooted in the management of recharging when you are running things off the batteries. there is always going to be some nominal draw on the power store, especially when going through inverter and converters to the 12v lights, 110v fridge & water heater both of which activates when needed.

so the charge controller is recharging batteries when it has solar power, but what happens to the output (appliances) during this process, are you basically opening up a larger circuit?

I expect that question is directed at SK so I'll stay out of it.

[Mike90250]

While the sun is powering the PV panels, the power goes to wherever needs it. If there is surplus, it goes to power loads (Like my water pump at noon) If no surplus, it gets consumed by the batterys, till they are full enough the controller throttles back the charge. At that point the panels are idle. Summertime, I have 4 & 5 hours in float, same array in winter might get 30 min in float with half the daily consumption.

[Sunking]

thanks for the belittling response sunking.

You must be a snow flake Millennial. I did not insult you, I agreed with you that it was a dumb question and you did nothing to answer your own question and think you are entitled to an answer with no work involved in getting what you want.

even though you haven't actually explained anything on the process of power regulation and distribution)

Huh? You did not ask anything about regulation and distribution. You asked how how a charge controller could charge a battery at the same time providing power downstream. That has nothing to do with regulation and distribution. The charge controller has nothing to do with it. It does not know there is a battery or anything downstream. It works just like your house, power goes where it is needed. You close a switch, and a light comes on. The generator at the power company does not know or care about your home or that you turned on a light.

Here is an analogy you might understand. You are on a Interstate Highway in heavy traffic. There are entry and exit ramps along the highway. Do you know or care which entry or exit ramps people are using or have any control where traffic is going. It goes wherever it is going.

Now if you want a detailed scientific explanation here you go. But be warned it is above your pay grade. Millenials were not taught any real math or science in school.

Kirrchoff Law states at any Node (junction) in an electrical circuit, the sum of the currents flowing into that node is equal to the sum of currents flowing out of the Node, Simplified means: The algebraic sum of the currents in a network of conductors meeting at a point equal ZERO amps.

In Millennial terms and explanation is: All the cars that got on the Interstate Highway, got off somewhere along the way and got to where they were going leaving zero cars on the Interstate.

Want another analogy as JPM said will make water flow out your ears? You have a water hose, a soaker water hose which is a hose with a cap on one end and the hose is full of holes for water to leak out. You connect the hose to a faucet and turn the pressure on. Does the Pump (charge controller) at the water plant know where the water is going? No sir it does not. All anyone knows is every drop went somewhere.