What Is the Best Way to Charge My Battery Bank?

Question:

I have received so many varied opinions, it’s time to ask the pros! I am replacing my house bank (12V) and would like your recommendations regarding the charging set-up and a new alternator. I have a 1300 amp hour bank of flooded lead acid, consisting of six 430 a/hr, 6V series/parallel; two Xantrex 40 amp true-chargers, and a 50 to 60 amp alternator. Unfortunately my pockets aren’t deep enough for my preference of Lithium batteries, so will have to stay with FLA. I have gone to 1300 a/h in an effort to limit my discharging to 75% of capacity. With a charging capacity of approximately 300 amps, (if that is correct) what is my best option for charging this bank, and what size of alternator would you recommend. We also have two Go-Power Solar panels for a total of 240 watts. Thanks for all your great articles and videos; a great asset to ensure our vessels are electrically safe. - Rick

Answer:

As a rule of thumb, you want your bulk charging to be at least 10% of deep-cycle capacity, 15% is even better. For you application, a minimum charge rate at bulk of 130 amps (10% of capacity) or 195 amps (15% of capacity).  Thanks for the feedback.  – Jeff