LF668 690AH 700Ah Mb56 Lf 668Ah Lifepo4 Cellule Lipo4 668 Ah 3.2V 688Ah 680Ah Lithium Battery 660AH Cell for 12V 24V 48V DIY BOX

The LF668 668AH Lifepo4 is a prismatic LiFePO4 cell rated at 668.0Ah nominal capacity and 2150.96Wh nominal energy at 3.22V nominal voltage, tested on fresh cells per the EVE specification sheet. This equals approximately 2.15kWh per cell, so a 16S series string reaches about 51.2V and roughly 34.2kWh. The rated values follow the standard charge-discharge conditions in the EVE datasheet (model JMRI-LF668-D06-01, version A).

The LF668 has a nominal voltage of 3.22V measured at 0.33C discharge at 25C plus or minus 2C between 2.5V and 3.65V. Charge cut-off voltage is 3.65V. Discharge cut-off is 2.5V when temperature is above 0C, and relaxes to 2.0V when temperature is at or below 0C. For external communication the cell is commonly described as a 3.2V cell.

Initial AC resistance (ACR) is 0.10mOhm plus or minus 0.05mOhm measured at 1kHz at 19% to 23% state of charge. DC resistance (DCR) is 0.25mOhm or less measured at 25C, 50% SOC, 1C discharge for 10 seconds. The low ACR supports consistent cell matching and balanced strings, and the low DCR keeps voltage stable under load steps.

Standard charge follows a staged profile at 25C plus or minus 2C: 1C charge to 80% SOC, then 0.8C to 3.5V, then 0.5C to 3.6V, then 0.1C to 3.65V. Maximum continuous charge current is 1C (668A) and maximum instantaneous charge is 2C for 30 seconds when SOC is at or below 80%. Standard discharge current is 0.5C (334A).

Maximum continuous discharge current is 1C, equal to 668A per cell. Maximum instantaneous discharge is 2C for 30 seconds when state of charge is at or above 30%. Standard discharge is 0.5C (334A). A 16S 51.2V string therefore sustains 668A continuously with 2C surge capability for 30 seconds, supporting whole-home backup and light commercial loads.

At 25C the LF668 delivers 4000 cycles with capacity retention of 80% SOH, using the standard staged charge profile and 1C discharge. At 45C it delivers 2000 cycles to 80% SOH. This means roughly 10-plus years of service at one daily cycle at 25C, which is an estimate for reference; the official rated figures are 4000 cycles at 25C and 2000 cycles at 45C.

A 16S series string of 16 LF668 cells reaches nominal 51.2V (16 x 3.2V) and about 34.2kWh of energy at 668Ah (configuration estimate). This matches the DC bus of mainstream 48V hybrid and off-grid inverters. Because each cell holds 2.15kWh, 16 cells form a full home battery without parallel strings, simplifying BMS and balancing.

QSO requires BMS monitoring of every cell in the pack, per the LF668 specification. Mixing different cell models in one pack is prohibited. A 16S BMS with per-cell voltage sensing, pack current sensing, over-charge, over-discharge, over-current, short-circuit and temperature protection is the recommended baseline for LF668-based packs.