I Have New AGM Batteries, Do I Need a New Charger?

Question:

Hi Jeff, I own a new-to-me Catalina 34 sailboat from the mid '80s. I'm replacing the (4) 6V flooded batteries with (4) new 225Ah AGM batteries. The separate starter battery is also a new 12V AGM. My question is, do I have to replace my current battery charger, a Guess Charge Pro from 2003? Can you give me some suggestions so far as output, brand,etc? Also, as I calculate it, my house bank wired in Serial/Parallel has a total 12V, 450Ah. Is this correct?  Thanks for your help.  - Dave

Answer:

Hi Dave,  I suggest you look at the Promariner ProNautic 50 or preferably 60 amp battery charger.  Your house battery bank capacity is 450Ah at 12 VDC and you need a minimum of 45 amps of charge rate. - Jeff