Both Charge Controller and Converter Charging Batteries?

i use both .. almost everyday

the solar does not keep up with all of our use without some converter charge time

there is no real reason to disconnect the converter , unless it malfunctions

djgodden wrote:
Since installing my solar panels (4x100W Renogy w/40amp MPPT controller) I've turned off the converter by throwing the breaker so the only thing charging the 4x6v batteries (225AH each)is the charge controller. Because the MPPT charges at 4 different rates depending on state of charge I felt it was best to disconnect the converter.

Do I HAVE to disconnect the convertor? Is it ok to leave both charging but not most efficient?

I only use one at a time, I have a switch wired inline with the solar controller to turn it off when the convertor is plugged in.

Thanks Gordon, because I didn't know how the controller worked I was unsure if having both on was counter productive. Seems they are a bit smarter than I thought they were.

djgodden wrote:
So, I take it having both the charge controller and the converter charging the batteries simultaneously isn't an issue? The whole reason to have a charge controller is to allow maximum efficiency in charging the batteries. Is the convertor just as efficient? It just feels contradictory.

Whichever charger holds the higher output voltage will be doing the charging, as higher voltage allows it to deliver higher current.

If you're on shore power, and your batteries are charged, your solar controller isn't going to supply much DC power, even in good sun. Your converter will be holding the DC voltage high, keeping the solar controller on standby or in float mode.

If you've just plugged into shore power (or started your generator), after several cloudy days, running the batteries down, both the converter and solar should both provide charging to the batteries. This is because the depleted batteries will hold the DC voltage low while in bulk and absorb states. This is assuming the typical 30-40 amp factory converter.

When the batteries get to ~85-90 percent and enter the float state, this is an unknown area. Both the converter and solar will want to enter a float charge mode, I guess whichever has the higher float voltage will "win" and the other will go into standby.

So, I take it having both the charge controller and the converter charging the batteries simultaneously isn't an issue? The whole reason to have a charge controller is to allow maximum efficiency in charging the batteries. Is the convertor just as efficient? It just feels contradictory.

pianotuna wrote:
I see, but the Magnum can do up to 125 amps and my solar system maxes out at 17.

(Actually I have the Magnum throttled to 109 amps).

That is why I'm not worried that the solar doesn't contribute.

Good point. With 100+ amps available from shore power, not much the solar can contribute.

I see, but the Magnum can do up to 125 amps and my solar system maxes out at 17.

(Actually I have the Magnum throttled to 109 amps).

That is why I'm not worried that the solar doesn't contribute.

pianotuna wrote:
Gordon3,

The problem is the voltage set points. They are slightly higher on the Magnum than on the solar panels. However, the solar takes care of the batteries between trips, so I do not wish to boost them.

I can, if I so wish trigger equalization voltage from the solar--but there is really no need to do so.

My thought was the solar controller could tell the Magnum charger to shut off during peak output.

X3 pianotuna. I had the same question and called Progressive Dynamics, Morningstar and Concord battery and they all indicated they would play well together and my experience is that they do.
When in doubt chat with one or more of the engineers.

Gordon3,

The problem is the voltage set points. They are slightly higher on the Magnum than on the solar panels. However, the solar takes care of the batteries between trips, so I do not wish to boost them.

I can, if I so wish trigger equalization voltage from the solar--but there is really no need to do so.