Adding additional batteries

[searaypuget]

My 08 280DA has the PD2030 converter/charger and two G27 batteries. I believe each one is connected to its own output of the charger and can be combined when starting the engine (496) by selecting both. I plan to add one ore two more batteries and want to make sure I am doing this right. I've done some similar work before on my customer RV so I am not completely new to this.

I can think of the following options and would like to hear your thoughts.

1. Rewire the current two batteries (use it for house) in parallel and add one starting battery (CCA 800+).
2. Just add the exactly same battery (deep cycle dual purpose) and connect it to the exiting battery in parallel.

What do you think? Thanks in advance.

 

[ttmott]

All battery manufacturers discourage mixing battery types (deep cycle vs cranking vs dual purpose) and different ratings (AH / CCA).
Also they discourage mixing old with new.
So, the Group 27 batteries are a dual purpose marine standard and a widely used size; stick with them, they are over 90 AH and just fine for your application. I use them (6 AGM's) in the 400DA and never have issues.
If you wanted to add house capability then I would parallel the two existing Gp 27 batteries over on the house side then buy a new Gp 27 for the other side.
The charger can deal with a old/new mix but to parallel old and new is not optimal.

 

[searaypuget]

All battery manufacturers discourage mixing battery types (deep cycle vs cranking vs dual purpose) and different ratings (AH / CCA).
Also they discourage mixing old with new.
So, the Group 27 batteries are a dual purpose marine standard and a widely used size; stick with them, they are over 90 AH and just fine for your application. I use them (6 AGM's) in the 400DA and never have issues.
If you wanted to add house capability then I would parallel the two existing Gp 27 batteries over on the house side then buy a new Gp 27 for the other side.
The charger can deal with a old/new mix but to parallel old and new is not optimal.

Thanks. I will stick to 27 and use the existing two as a house.


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