Running load from PV panel when battery is fully charge

[farrukhtalib]

Hi, every one There is a question in my mind regarding operationn of a charge controler. When charge controler disconect battery from solar panel when it is fully charge then how it manages to run load?? I mean if there is a voltage regulator between load and panels or eles. pls tell me abut the phenomenon

Regards

[daz]

When charge controler disconect battery from solar panel when it is fully charge then how it manages to run load??

The charge controller never disconnects from the battery. The charge controller disconnects the solar panels from the battery.
The load is not connected to the charge controller, so it does not matter that the solar panel is disconnected from the battery. The load is connected straight to the battery (or to the inverter, which is connected to the battery).

[Cal Dan]

disconnected panels

Is there a problem with having panels in the sun and not being connected?

I have 2 extra panels that my small battery bank doesn't really need. I would like to put them up and just leave them turned off most of the time (or let the charge controller do that for me). The reasons for doing this are 1- they would be there if I could consume more power during the day, 2- they would provide shade for a very hot room, 3- just get them out of my storage. None of these reasons are worth ruining good panels. Is this bad for the panels?

Thanks, Dan

[daz]

Is there a problem with having panels in the sun and not being connected?

The solar panels won't be damaged by leaving them disconnected and in the sun. They are current sources, so if they are not connected to a load, they will just sit there and do nothing...

[farrukhtalib]

Running load from PV panel when battery is fully charge

The charge controller never disconnects from the battery. The charge controller disconnects the solar panels from the battery.
The load is not connected to the charge controller, so it does not matter that the solar panel is disconnected from the battery. The load is connected straight to the battery (or to the inverter, which is connected to the battery).

Then what will happans to the exta energy which is being produced by the panels . Or read my query as "what will happan when battery is fully charge and still panels are producing watts?? may it goes to load (invertor) or else"

[Sunking]

Then what will happans to the exta energy which is being produced by the panels . Or read my query as "what will happan when battery is fully charge and still panels are producing watts?? may it goes to load (invertor) or else"

When the battery is fully charged, and no load is demanding power, the panels are not generating power, thus the power goes no where because there is no power. That is one reason why off grid battery systems are so inefficient.

[farrukhtalib]

Running load from PV panel when battery is fully charge

When the battery is fully charged, and no load is demanding power, the panels are not generating power, thus the power goes no where because there is no power. That is one reason why off grid battery systems are so inefficient.

Thank you your reply has increased my knowldge, but still I want to learn more now my question is if I am using a 50 amp/h battery (AGM) panels instaled are yeilding 200 waatts and load conected is 50 watts, Now if the battey is fully charge sun is there and load is demanding current then what will be the seen

[Sunking]

Thank you your reply has increased my knowldge, but still I want to learn more now my question is if I am using a 50 amp/h battery (AGM) panels instaled are yeilding 200 waatts and load conected is 50 watts, Now if the battey is fully charge sun is there and load is demanding current then what will be the seen

The panels will supply the 50 watt load and the battery sits there and collects dust. If th eload demands more than the panel can deliver the battery makes up the difference.

[inetdog]

... I am using a 50 amp/h battery (AGM) ....

It is a 50AH (Amp-Hour) battery, not a 50 Amp per hour battery. The battery can deliver 2.5 Amps continuously for 20 Hours, for a total of 50 Amp-Hours.

[farrukhtalib]

The panels will supply the 50 watt load and the battery sits there and collects dust. If th eload demands more than the panel can deliver the battery makes up the difference.

Actually there is a communication gap, I am still unable to ask what i want, I may ask again that Let us consider any off grid solar system if battery bank is fully charged then charge controller will disconect the solar panel from battery bank, so ultimatly load will seek power from battery bank and then battery will began to lose charge. Now what I want to learn is that "If there is any arrangement possible that load may seek power from panels when the battery bank is fully charged and panels are still generating enough power to drive the saaid load leaving fully charged battery bank intact for the use when there is dusk?"

[inetdog]

Actually there is a communication gap, I am still unable to ask what i want, I may ask again that Let us consider any off grid solar system if battery bank is fully charged then charge controller will disconect the solar panel from battery bank, so ultimatly load will seek power from battery bank and then battery will began to lose charge. Now what I want to learn is that "If there is any arrangement possible that load may seek power from panels when the battery bank is fully charged and panels are still generating enough power to drive the saaid load leaving fully charged battery bank intact for the use when there is dusk?"

When the battery is fully charged, the CC will try to hold a specific voltage, called the Float voltage on the batteries. It will NOT disconnect, it will just not try to send any more current to the batteries than they will accept at the Float voltage. Any load current drawn will tend to reduce this voltage and the CC will contribute enough current to keep the voltage constant. So the CC will still be powering the load from the panels even though the batteries are full.

If the load is too heavy (more than the panels can deliver) then the remainder will come from the batteries.
If the battery voltage goes low enough, the CC will switch to a different charging mode and voltage, but still cannot deliver more power than the panels are producing.

Whether the CC sends the full power from the panels to the batteries in the morning depends on how low the battery voltage has been pulled during the night.

Note that what I am describing is what is called a three or four stage charger. A very cheap mains driven charger might actually disconnect completely when the batteries reach a high enough voltage and reconnect when it drops below a set lower level. But a solar CC will not work this way.

[Beanyboy57]

Actually there is a communication gap, I am still unable to ask what i want, I may ask again that Let us consider any off grid solar system if battery bank is fully charged then charge controller will disconect the solar panel from battery bank, so ultimatly load will seek power from battery bank and then battery will began to lose charge. Now what I want to learn is that "If there is any arrangement possible that load may seek power from panels when the battery bank is fully charged and panels are still generating enough power to drive the saaid load leaving fully charged battery bank intact for the use when there is dusk?"

Maybe it is possible if your connection from your CC and your connection TO to your inverter are one and the same, ie: they connect to the same battery terminals. Perhaps if the battery is totally charged then the current from the CC will flow directly to the inverter, thus bypassing your battery. Just a thought, not sure if this is what would actually happen.
If you have a battery monitor you may be able to see in real time what the SOC of the batteries are while operating a load from your inverter.

[farrukhtalib]

When the battery is fully charged, the CC will try to hold a specific voltage, called the Float voltage on the batteries. It will NOT disconnect, it will just not try to send any more current to the batteries than they will accept at the Float voltage. Any load current drawn will tend to reduce this voltage and the CC will contribute enough current to keep the voltage constant. So the CC will still be powering the load from the panels even though the batteries are full.

If the load is too heavy (more than the panels can deliver) then the remainder will come from the batteries.
If the battery voltage goes low enough, the CC will switch to a different charging mode and voltage, but still cannot deliver more power than the panels are producing.

Whether the CC sends the full power from the panels to the batteries in the morning depends on how low the battery voltage has been pulled during the night.

Note that what I am describing is what is called a three or four stage charger. A very cheap mains driven charger might actually disconnect completely when the batteries reach a high enough voltage and reconnect when it drops below a set lower level. But a solar CC will not work this way.

Thank you your reply is spacific, now things a clear for me. It means that load is at first priorty i.e, current will flow towards load fist and the remaing current will charge the battery

[Sunking]

Actually there is a communication gap, I am still unable to ask what i want, I may ask again that Let us consider any off grid solar system if battery bank is fully charged then charge controller will disconect the solar panel from battery bank, so ultimatly load will seek power from battery bank and then battery will began to lose charge. Now what I want to learn is that "If there is any arrangement possible that load may seek power from panels when the battery bank is fully charged and panels are still generating enough power to drive the saaid load leaving fully charged battery bank intact for the use when there is dusk?"

........(Mod Edit)

I have already fully explained everything to you already.

• When battery is fully charge, bright sun, , no load the panels and battery do nothing. There is no place for power to go. The system sits there and collects dust.
• Battery fully charged, full sun, 200 watt system, 50 watt load, the panels provide the 50 watts to the load, and the batteries sit there in float mode fully charged up and collect dust.
• Battery fully charge, full sun, 200 watt system, 400 watt load. Panels provide about 200 watts to the load and the battery makes up for the shortage and begin discharging.
• Batteries in discharged state, full sun, 200 watt system, no load, Batteries are taking about 200 watt charge from the panels.

That is all that can happen. Everything has to balance and = 0