Combine in parallel to get the required capacity, then series 4 banks together to give nominally 12V.
Ideal for Second/house battery and engine cranking.
 
SPECIFICATIONS
3.2V-40Ah
Voltage 3.2 V 
Nominal Capacity 40 Ah @ 0.3C
Weight Approx 1.5kg
Dimensions 116 x 46 x 180(H)mm
DC internal  resistance (max)     <1.0 mΩ 
Operating temperature 0°C to +45°C
Storage temperature -20°C to +55°C
SOC window 10% > 90%
Charge type CC/CV
Quick charge current 40A
Quick discharge current 80A
Standard discharge current 13A
Standard charge current 13A
Max operating discharge current 120A
Max pulse discharge current (<10s) 400A
150A Discharge capacity >90% capacity
Minimum Voltage 2.5V
Maximum Charge Voltage 3.65 V 
Life cycle @ 0.3C, 80% DOD, 2,000
Ceramic membrane technology.
Flame retardant housing.