Charger Question
 

I have an existing Interstate Battery for starting. Lead 24 Series.

I was looking to purchase 2 Deka AGM Series 31 for the stereo bank.
They are 20ah rate = 105 each.

Using the Blue Sea Add-A-Battery.

1) Would a 20amp onboard charger be enough - 2 bank?
I'm not worried about the starting battery getting dragged down.

2) Any issues with Lead/AGM and the Charger?
Not sure if there are 'modes' for the charger to know what type of batteries.

Appears most people are using Progress Intell or Pro Sport.

Mark

Been reading about the ProSport Models.

2 bank vs 3 bank - any benefits on the 20amp models?

Can you hook-up #1 on Starting Battery, #2 and#3 on the Stereo Bank?

You can use a 3 bank system, but I don't think it is necessary to charge your starting battery since your alternator takes care of that battery. I'm running 3 batteries (one starter, and two accessory batteries) and only use a two bank charging system for the accessory batteries. Just to let you know, in the 3 or 4 years of using a 2 bank charging system I haven't had any issues with my starting battery.

In your situation a three bank charger offers no advantage. In fact, unless you separate the two group 31 batteries that are in parallel, the three bank charger will function as a two bank charger.

Most chargers are 'distribute on demand' so the appropriate charge level will go to the bank in need.

For 170 collective amp/hours a 20 amp charger is fine.

It would be a good idea to use a charger that has independent AGM and flooded settings per each bank. Any good charger will be selectable but not all are independently selectable per bank. Or, change your starting battery over to AGM.