best approach to string 12 2 volts agm batteries

DarkstormNH

Good folks

i have 12 2 volts batteries, should i string one 24 volts or 2 parallel string at 6*2=12 volts than parallel for 24 volts
feedback suggestions will be appreciated

Estragon

Parallel 2x12v strings will give you a higher capacity 12v bank. If you need 24v with 12x2v cells, it has to be a single series string.

BB.

What are your needs? 12 volt or 24 volt. The 12 volt and 24 volt configurations store exactly the same amount of energy.

12 volt, more off the self small stuff to run. 24 volt, less voltage drop, smaller cables, more efficient use of charge controller (2x more solar panels at 24 volt battery bank).

12 volt bank needs heavier cables, has more issues with voltage drop in cables.

-Bill

PS, what is the AH of the cells?

mike95490

are the batteries sealed or flooded ?   Series is the better configuration, if you require 12V, there can be imbalance issues between strings not sharing equally,  diagonal wiring can ameliorate some of that issue.

 Sealed batteries have more issues when in parallel, because of their low internal resistance

http://www.smartgauge.co.uk/batt_con.html

DarkstormNH

BB. said:

What are your needs? 12 volt or 24 volt. The 12 volt and 24 volt configurations store exactly the same amount of energy.

12 volt, more off the self small stuff to run. 24 volt, less voltage drop, smaller cables, more efficient use of charge controller (2x more solar panels at 24 volt battery bank).

12 volt bank needs heavier cables, has more issues with voltage drop in cables.

-Bill

PS, what is the AH of the cells?

each batterie is 700 amp hour, I will need 24 volts since the inverter is 24 volts

Estragon

Then there is no choice. With 12x2v cells, you will have a single series string of ~700ah @ 24v. There is no parallel option.

DarkstormNH

Estragon said:

Then there is no choice. With 12x2v cells, you will have a single series string of ~700ah @ 24v. There is no parallel option.

thank you very much

BB.

You can parallel for 12 volts @ 1,400 AH. And that is 140 amps for a 10% rate of charge.

A lot of current, heavy cabling, and 2x solar charge controllers.

Of course, it does depend on your needs.

Bill

Sol4r

Estragon said:

Then there is no choice. With 12x2v cells, you will have a single series string of ~700ah @ 24v. There is no parallel option.

good to know