Advantage 6V Series vs 12V Parrallel Bank

[Wanderer2011]

Ok, what is the Pro's/Con's of 6V Series or 12v Parrallel Battery bank setup, other than price.

Looking at this:
Bank 1: 2 T-125 (6v) in Series 240AH total

or

Bank 1: 2 SCS200 (12v) in Parrallel 230 AH total

Second bank will be built later with the same configuration as Bank 1
BMV600 will monitor Bank 1.
Xantex battery charger will be setup to charge both battery banks, through EchoCharger
One bank will be on Port side (1) the other STarboard side (2).

I have a load plan for the electrical an this will meet my needs, and I'll be using the bank to start a M18 diesel engine.

Thanks in advance.

[night0wl]

If you can only fit 2 batteries, then I would go with a Bank of the SCS200 (12v) in parallel.

Here is the reason. If you're using this as your one and only bank, and a single cell goes bad (which ruins the battery that the cell is in), then in your first setup (6v in series), you will lose the *ENTIRE* battery bank as most electronics require 12v.

In a 2 x 12v battery in parallel setup (your second scenario) if you lose a battery due to a bad cell, at least you have 1 additional battery that is capable of putting out 12v allowing you to limp home. Sure your capacity is diminished, but this is an emergency situation...and a prudent sailor tries to prepare.

Ideally, in a long term cruising scenario, I would have 4 x 6v batteries wired in series/parallel. This would give me 2 x 12 banks totalling ~400 amp hours. This is a lot of weight and the cabling and charging equipment can be expensive and require upgrades, as well as the ongoing battery maintenance....however I would have the most peace of mind with that setup that my bank(s) can provide the capacity and redundancy I seek.

[mitiempo]

While the above post is true, the 6 volt "golf cart" type batteries have thicker plates and will outlast most 12 volt batteries by quite a large margin.

A good solution would be a bank of two 6 volt golf carts in series (or 4 in series/parallel) and a separate 12 volt battery for engine starting or emergency use.

[btrayfors]

+1 what Brian said.

Also, don't wait too long to get the second bank. And, when you do, consider linking them all together as one big house bank. With a separate start battery, as Brian suggested, maintained by an EchoCharge.

Bill