Another Solar Regulator Question

[rick&sue]

I have a a Morningstar Sun Saver Duo Controller which works well for two groups of batteries - House and Engine, but have nothing for the thruster battery. I would like to add a double pole, double throw switch to be able to switch from the engine battery to the thruster battery. Has anybody tried this? Other ideas to be able to charge three sets of batteries using the Duo Controller?
Thanks!
Rick

 

[knotflying]

If it were me (and I did this) I would run a positive lead to a small on/off battery switch and from that switch to your house bank. That will allow you to join the thruster to the house when on the hook or isolate it if you wish. I actually leave mine in the on position all the time. This way when on the hook I have the advantage of three batteries.

Mike Rizzo

 

[Levitation]

Interesting.
If you have the Blue Seas ACR relays on your Tug (standard as far as I know) then a solar charger voltage of 13.6v placed on the engine battery should engage the relays making all three battery sets a single bank.
It may be that the charge regulator on the solar panel is limiting the voltage just enough to not let that happen.
In that case Mike's suggestion will work just fine.
Blue Seas makes a fine switch for that purpose.

 

[pugtug613]

Why not just use the parallel switch? Doesn't that combine all the batteries?

 

[rick&sue]

Thanks everyone for the great ideas. If I understand the reference to a parallel switch - mine combines only the house with the engine. The thruster battery remains isolated. This is a very early build, I'm not aware there is an ACR onboard. I did look up the Blue Sea ACR and it appears this unit will do what I am looking for, the only thing I'm not sure of, is if the solar panel will reach 13 volts during charging (required charging voltage to initiate the relay to charge the second battery). I've only had the boat in the water once and I was much overwhelmed so I don't know what the voltage is when it is in sunlight charging the batteries. It's currently buried in a hanger with minimal exposure to sunlight. Would appreciate input as to what voltage the solar panel charger typically puts out. (30 below zero wind chill tonight and tomorrow (gotta love Wisconsin))
Rick

 

[knotflying]

Rick&sue,
Denny is correct regarding the relays and their joining the batteries during a charge. My option of joining the thruster to the house was that while on the hook overnight you will have all three joined. It is my understanding that once you are not getting a charge then the ACR's will isolate the batteries. Hence all the batteries are isoleded from each bank. Your concern during charge mode would also be eliminated if you choose to keep the switch installed between thruster and house in the on position.