Victron Lead - carbon 12V 160Ah Batteries

Failure modes of flat plate VRLA lead acid batteries in case of intensive cycling
The most common failure modes  are:

•   Softening or shedding of the active material. During discharge the lead oxide (PbO2) of the positive plate is transformed into lead sulfate (PbSO4), and back to lead oxide during charging. Frequent cycling will reduce cohesion of the positive plate material due to the higher volume of lead sulfate compared to lead oxide.

•   Corrosion of the grid of the positive plate.  This corrosion reaction accelerates at the end of the charge process due to the, necessary, presence of sulfuric acid.

•  Sulfation of the active material of the negative plate. During discharge the lead (Pb) of the negative plate is also transformed into lead sulfate (PbSO4). When left in a low state-of-charge, the lead sulfate crystals on the negative plate grow and harden and form and impenetrable layer that cannot be reconverted into active material. The result is decreasing capacity, until the battery becomes useless.

Lead-carbon: better partial state-of-charge performance, more cycles, and higher efficiency
Replacing the active material of the negative plate by a lead-carbon composite potentially reduces sulfation and improves charge
acceptance of the negative plate.

• Less sulfation in case of partial state-of-charge operation.
• Lower charge voltage and therefore higher efficiency and less corrosion of the positive plate.
• And the overall result is improved cycle life.

Tests have shown that our lead-carbon batteries do withstand at least five hundred 100% DoD cycles.  
The tests consist of a daily discharge to 10,8V with I = 0,2C₂₀, followed by approximately two hours rest in discharged condition, and then a recharge with I = 0,2C₂₀.
(Several manufacturers of lead-carbon batteries claim a cycle life of up to two thousand 90% DoD cycles. We have not yet been able to confirm these claims)

Datasheet:

• Capasity (20 hr / 25 °С): 160 Ah

• Self -Discharge: less than 2% per month at 20°C ???

• Float design life: 12 years at 20°C ????

• Cycle design life:

           - 500 cycles at 100% discharge

          - 1000 cycles at 60% discharge

          - 1400 cycles at 40% discharge

• Dimentions: (l x b x h): 532 x 207 x 215mm
• Weight: 55kg