littleharbor2
Solar Addict
28 volts x 60 amps = 1680 watts. I think you're not overpaneled at the moment. Considering you can expect about 75-80% of nameplate rating of your panels I'd say you should be able to add more. MPPT controllers will throttle back when needed and you won't ever see more than 60 amp output regardless how much solar is connected. What is the highest wattage you have seen with your 1600 watt array?
You're correct about balancing issues. One remedy is using larger batteries. That being said lots of people have more than 2 strings. You need to wire your bank carefully. Study this from Smart Gauge. Example #3 is the most common strategy for wiring up 3+ strings of batteries. http://www.smartgauge.co.uk/batt_con.html
As to charging, AGM batteries will take up to 20% of their amp hour rating in charging amps. 15 % is a healthy charge so a 450 amp hour bank would be happy with 60 amps of current.
You're correct about balancing issues. One remedy is using larger batteries. That being said lots of people have more than 2 strings. You need to wire your bank carefully. Study this from Smart Gauge. Example #3 is the most common strategy for wiring up 3+ strings of batteries. http://www.smartgauge.co.uk/batt_con.html
As to charging, AGM batteries will take up to 20% of their amp hour rating in charging amps. 15 % is a healthy charge so a 450 amp hour bank would be happy with 60 amps of current.