Question on off-grid system

[Essay]

I have a question on off-grid system with a charge controller and an inverter. In a sunny day when the batteries are fully charged does the PV supply electricity directly to the loads through the inverter without first 'going' to the battery?
Essay

[Sunking]

Depends. If the batteries are fully charged up and cycled to float, and the load demand does not exceed what the panels can produce would come form the panels. If not then the batteries. Keep in mind solar panels only generate their full power for a hour or two around noon if the sky is clear and bright.

[Essay]

Depends. If the batteries are fully charged up and cycled to float, and the load demand does not exceed what the panels can produce would come form the panels. If not then the batteries. Keep in mind solar panels only generate their full power for a hour or two around noon if the sky is clear and bright.

Thanks Sunking. My system is in Eritrea (Africa) where we get an average 7hrs of sunlight. The inverter is connected to the batteries not to the charge controller. My question is when I see the indicator in the charge controller that the battery is full then does the current go directly to the loads bypassing the battery? And if as you mentioned the load is greater than the pv can produce then does the load take part from the pv and the remaining from the battery?

[Sunking]

Thanks Sunking. My system is in Eritrea (Africa) where we get an average 7hrs of sunlight.

No place on earth gets 7 Sun Hours. You are confusing daylight hours with sun hours. Not important for this convesation

The inverter is connected to the batteries not to the charge controller.

It had better be connected to both electrically or it will not work. Controller to Battery to Inverter.

My question is when I see the indicator in the charge controller that the battery is full then does the current go directly to the loads bypassing the battery? And if as you mentioned the load is greater than the pv can produce then does the load take part from the pv and the remaining from the battery?

The power comes from the highest source period. If the batteries are fully charged, and the panels are the higher source, they will provide the power. Otherwise the batteries will make up any and all shortages.

The current net sum has to be ZERO.

[Essay]

Thanks. You have answered my question.

[javadz]

No place on earth gets 7 Sun Hours. You are confusing daylight hours with sun hours. Not important for this convesation



It had better be connected to both electrically or it will not work. Controller to Battery to Inverter.

The power comes from the highest source period. If the batteries are fully charged, and the panels are the higher source, they will provide the power. Otherwise the batteries will make up any and all shortages.

The current net sum has to be ZERO.

excuse me to ask :
when the batteries are fully charged ,and the current présent from panels in the outpout of charge controler(bat-,bat+) is greater than the current the load demand ,where will the remaining current go ,it will overcharge the batteries?
NB :assuming the load is connected to the battery and the charge controler is without terminal load outpout (only pv and battries terminal)

[paulcheung]

The charge controller only pull what ever the amount of power to charge the battery and supply the load, When the panels have more power it just not produce because the charge controller does not demand it.

[boostinsteve]

excuse me to ask :
when the batteries are fully charged ,and the current présent from panels in the outpout of charge controler(bat-,bat+) is greater than the current the load demand ,where will the remaining current go ,it will overcharge the batteries?
NB :assuming the load is connected to the battery and the charge controler is without terminal load outpout (only pv and battries terminal)

The whole point of a charge controller is to maintain a set voltage on the batteries once they are charged. A load can be added to the system, and the controller will only supply the demand of what is needed. If there is more power available from the panels, the controller will only allow what is needed to supply the loads, and maintain a set voltage. If the voltage goes up, then the controller is supplying more current than is necessary, and should back off on the pwm driving the mosfets. The extra power is just wasted, it goes no where.

You have asked this same question in a bunch of threads. Hopefully this answered it for you, and we can move to other things.

[Sunking]

excuse me to ask :
when the batteries are fully charged ,and the current présent from panels in the outpout of charge controler(bat-,bat+) is greater than the current the load demand ,where will the remaining current go ,it will overcharge the batteries?
NB :assuming the load is connected to the battery and the charge controler is without terminal load outpout (only pv and battries terminal)

It goes no where the potential power is lost forever. In a properly designed off grid system a significant amount of power is lost and never used. That is why it is impossible to for an off-grid system to ever save you money or offset emissions.

[javadz]

thank you all for your responses