Victron LiFePO4 Lithium Battery 12.8V/200Ah-a - Smart BAT512120610, 3 year warranty.
- With integrated cell balancing
- Can be parallel and series connected
- Bluetooth app available to monitor cell voltage and temperature
Why lithium-iron-phosphate?
Lithium-iron-phosphate (LiFePO4 or LFP) is the safest of the mainstream li-ion battery types. The nominal voltage of a LFP cell is 3,2V (lead-acid: 2V/cell). A 12,8V LFP battery therefore consists of 4 cells connected in series; and a 25,6V battery consists of 8 cells connected in series.
Rugged:
A lead-acid battery will fail prematurely due to sulfation:
- If it operates in deficit mode during long periods of time (i.e. if the battery is rarely, or never at all, fully charged).
- If it is left partially charged or worse, fully discharged (yacht or mobile home during wintertime).
A LFP battery does not need to be fully charged. Service life even slightly improves in case of partial charge instead of a full charge. This is a major advantage of LFP compared to lead-acid. Other advantages are the wide operating temperature range, excellent cycling performance, low internal resistance and high efficiency.
LFP is therefore the chemistry of choice for very demanding applications.
Efficient:
In several applications (especially off-grid solar and/or wind), energy efficiency can be of crucial importance. The round trip energy efficiency (discharge from 100% to 0% and back to 100% charged) of the average leadacid battery is 80%. The round trip energy efficiency of a LFP battery is 92%. The charge process of lead-acid batteries becomes particularly inefficient when the 80% state of charge has been reached, resulting in efficiencies of 50% or even less in solar systems where several days of reserve energy is required (battery operating in 70% to 100% charged state). In contrast, a LFP battery will still achieve 90% efficiency under shallow discharge conditions.
Size and weight:
Saves up to 70% in space
Saves up to 70% in weight
Expensive?
LFP batteries are expensive when compared to lead-acid. But in demanding applications, the high initial cost will be more than compensated by longer service life, superior reliability and excellent efficiency.
Bluetooth:
With Bluetooth cell voltages, temperature and alarm status can be monitored.
Very useful to localize a (potential) problem, such as cell imbalance.
Victron LFP batteries have integrated cell balancing and cell monitoring. Up to 5 batteries can be paralleled and up to four batteries can be series connected,so that a 48V battery bank of up to 1500Ah can be assembled. The cell balancing/monitoring cables can be daisychained and must be connected to a Battery Management System (BMS).
Battery Management System (BMS):
The BMS will:
- Generate a pre-alarm whenever the voltage of a battery cell decreases to less than 3,1V (adjustable 2,85 - 3,15 V).
- Disconnect or shut down the load whenever the voltage of a battery cell decreases to less than 2,8V (adjustable 2,6 V - 2,8 V).
- Stop the charging process whenever the voltage of a battery cell increases to more than 3,75 V or the temperature increases to more than 60°C.
