Magnum MSI2012 inverter/charger

[lazet15]

I have a Magnum MSI2012 inverter/charger that came with four 6V batteries. The batteries are in need of replacement. I am thinking of switching to two 12V batteries instead. Can I do this and what are the pros/cons of doing this?

[jrsick]

Do you know the amperage of the 6V and 12V batteries? What type of batteries are they; deep cycle, deep cycle marine, or starting?

[lazet15]

They are 4 Trojan T-125 6v deep cycle batteries. All connected in series.

[jrsick]

You will need to know the amp/hr of the 6v Trojans vs the 12v. Simple math leads you to take the configuration that produces the highest amp/hr output. However, 6v cells are larger than 12v cells and most will tell you that the 6v batteries give more stable power and have longer life.
Hopefully there are some big boat guys online that can share their experiences.

[shrew]

The 6v batteries are in Series-Parallel. You can replace each set of 2x6v with 12V. The wiring will be different, so don't accidentally make the bank 24v by wiring the 12 volt in series-parallel only.