Question on solar charging

[Jmooney]

Does the solar controller output to the battery bank need to be isolated from the RV converter/ charger to prevent damage when on shore power?

[Mustang65]

Originally Posted by Jmooney

Does the solar controller output to the battery bank need to be isolated from the RV converter/ charger to prevent damage when on shore power?

No, they work together with no problems. I rewired my TT's internal charge controller to its own AC breaker (I had 2 spare spaces for breakers) and I turned my TT's internal charger off, once I saw that the 250 watt panel was enough to charge the batteries without the need from the TT's unit. That was May of 2012. I have not turned on the TT's unit since then. Saves a few $$$ at home also, so I don't have to pay the Electric company.

Just make sure that you put fuses between the panel(s) and Solar charge controller and a fuse between the Solar charge controller and the batteries. I installed 30 amp ANL fuses. I also installed a disconnect switch between the panel and the solar charge controller. You can see my wiring diagram by clicking on the link below.

Don

[waynem]

How about the tow vehicle? If I'm driving down the road and the solar controller is charging away and is in its absorption phase (14.4-14.8v depending on settings) I am concerned about that voltage feeding back through the TV connector and its effects on the TV battery and electronics. Do those with solar systems disconnect the charge wire in the trailer connector? I'm thinking about installing solar this year and this is one of the questions I still have.

Wayne

[Mustang65]

Originally Posted by waynem

How about the tow vehicle? If I'm driving down the road and the solar controller is charging away and is in its absorption phase (14.4-14.8v depending on settings) I am concerned about that voltage feeding back through the TV connector and its effects on the TV battery and electronics. Do those with solar systems disconnect the charge wire in the trailer connector? I'm thinking about installing solar this year and this is one of the questions I still have.

Wayne

You add a 30Amp blocking diode between the TT and the TV. This keeps the TT's voltage from feeding back to the TV.
Don

[Mustang65]

The 14+ volts should not do anything to the TV as the TV's system also produces that voltage when charging the TV's battery. My F150 with the 200+ amp alternator has reached 14.8VDC, when the truck was not used for awhile and after starting it. If you are still concerned, add the 30 amp blocking diode between the TV and the TT. This will isolate the TV from TT's voltages (voltage will flow from TV to TT, but not back). You can find blocking diodes on line for about $5 - $10, but it has to be a 30 amp model. I have my Solar Charge Controller set so that I manually start the EQUALIZE cycle. This cycle can produce voltages up to 16VDC. I disconnect the TT from the batteries while EQUALIZING the batteries. I perform this process about once every 3 months or sooner if I have had 5 or more deep discharges.
Don

[Jmooney]

Originally Posted by Mustang65

The 14+ volts should not do anything to the TV as the TV's system also produces that voltage when charging the TV's battery. My F150 with the 200+ amp alternator has reached 14.8VDC, when the truck was not used for awhile and after starting it. If you are still concerned, add the 30 amp blocking diode between the TV and the TT. This will isolate the TV from TT's voltages (voltage will flow from TV to TT, but not back). You can find blocking diodes on line for about $5 - $10, but it has to be a 30 amp model. I have my Solar Charge Controller set so that I manually start the EQUALIZE cycle. This cycle can produce voltages up to 16VDC. I disconnect the TT from the batteries while EQUALIZING the batteries. I perform this process about once every 3 months or sooner if I have had 5 or more deep discharges.
Don

Don - do you run at 16 volts because that's what the battery manufacturer says is the absorption target voltage?

Exide ( mine ) says 14.8 maximum


Or is " equalizing different " than absorption .

[Jmooney]

Never mind, I see there is a difference... I need to see if the new controller I ordered, or the 5er converter has that option