charging using grid and solar

[abozakaria]

If I have an inverter with ac charger and a solar array connected to a battery bank
could charging from ac confilict with charging from solar as the could be as connecting 2 chargers in parrallel..I think there must be some comunication for both chargers

[inetdog]

If I have an inverter with ac charger and a solar array connected to a battery bank
could charging from ac confilict with charging from solar as the could be as connecting 2 chargers in parrallel..I think there must be some comunication for both chargers

The two communicate after a fashion by both looking at the same battery voltage (except for voltage drop in their separate wires to the batteries.)

The main reasons that that they would need to communicate are:
1. To make sure than in Bulk stage the two chargers together do not deliver more current than the battery bank can handle.
2. To set up a priority of when only solar will be used for charging and when just ac or both chargers can be used. If the AC is coming only from an inverter supplied from the batteries, it usually does not make sense to use the ac charger.

[Sunking]

Are you connected to the grid?

[abozakaria]

I only connect to grid for 6 hour max a day 18 hours we are off the grid

[Silver_Is_Money]

I'm also interested in the answers to be found in this thread, but from the perspective of a grid tied with battery back-up system. In such a system, can the grid be utilized in some way to supplant the panels in recharging the battery bank (for such times where in an off grid system the generator would be called into this service)?

[inetdog]

I'm also interested in the answers to be found in this thread, but from the perspective of a grid tied with battery back-up system. In such a system, can the grid be utilized in some way to supplant the panels in recharging the battery bank (for such times where in an off grid system the generator would be called into this service)?

It certainly can be done, using a hybrid inverter with a degree of control and flexibility that depends on the brand and setup of the system components.

But why would you want to do this?
The only justification for that kind of setup is when the grid is so unreliable that you do not want to depend on a generator. Essentially a giant UPS with optional solar PV input to the batteries.

If power failure is infrequent and less than 1 day at a time, I see no point in adding solar to the battery powered system.
Although you may find that a hybrid system that sells to the grid most of the time, like a simple GTI, would make economic sense. It would minimize the cycle load on the batteries between power outages.
You would still also need a generator if your goal is reliable power.

[abozakaria]

Icant run generator 18 hours a day ..it will costme at least 18l of desil a day which will cost 36dolar a day and more than 1000 dolar a month ...and the sound of the generator and the maintanance and the store of desil ...etc
am asking this question to increase my knowledge

[SunEagle]

Icant run generator 18 hours a day ..it will costme at least 18l of desil a day which will cost 36dolar a day and more than 1000 dolar a month ...and the sound of the generator and the maintanance and the store of desil ...etc
am asking this question to increase my knowledge

Are you actually without grid power for 18 hours every day?

If the grid outage is only a couple of hours a day or less you won't be running that generator that much and it will be less expensive than maintaining a large battery bank.

[abozakaria]

Are you actually without grid power for 18 hours every day?

If the grid outage is only a couple of hours a day or less you won't be running that generator that much and it will be less expensive than maintaining a large battery bank.

Not only me 1.8 milion people in gaza strip off the grid 18 hours a day duo to closer and bombing the main power plants by isreal forces

[SunEagle]

Not only me 1.8 milion people in gaza strip off the grid 18 hours a day duo to closer and bombing the main power plants by isreal forces

Ouch. My heart goes out to you and your family living in a war zone.

I can see where batteries is a necessity to keep the lights on.

[Sunking]

If I have an inverter with ac charger and a solar array connected to a battery bank
could charging from ac conflict with charging from solar as the could be as connecting 2 chargers in parallel..I think there must be some communication for both chargers

Should not be a problem and can be fine tuned if you have some control on at least one device to set the voltage. Some manufactures do sell hybrid inverters and chargers designed to communicate, but it is not necessary if you understand how the equipment operates.

Physics dictates which source of power the batteries will use to charge themselves with. The source with the highest energy level will always be used. If the highest energy source cannot meet the demands of the batteries, the secondary source will also be used. That tells us The commercial AC power will be the highest source when it is available. Armed with that you want the AC charger built into the inverter voltage set point just a little higher than the solar charge controller. Only has to be 1/10 of a volt.

Under normal conditions done this way AC power will be your primary charging source. If the panels demand more than the AC charger can provide will turn on and supplement. This will give you the fastest possible recharge time between interruptions. When AC power is off, the panels take over if available during daylight hours.

In the mean time I will pray for peace for you.

[abozakaria]

Thanks alot
by voltage set point do you mean bulk voltage?

[Sunking]

Thanks alot
by voltage set point do you mean bulk voltage?

Yes Sir, raise all of them Bulk, Absorb, and Float .1 volt higher than the charge controller if you can but Bulk should be the trigger.