12 V LiFePO4 Battery Packs (12.8 V)

Why 12 V packs are the most common drop-in replacement

A 12.8 V nominal LiFePO4 pack sits inside the voltage window most 12 V equipment already expects: 10 V to 14.6 V. That makes it the one chemistry you can usually substitute into an existing system without changing the inverter or the alternator.

The gain is not only weight. Lead-acid is normally sized at 50 % depth of discharge to reach its rated cycle life, so a "100 Ah" lead-acid bank is effectively a 50 Ah bank. A LiFePO4 pack is specified at 80–90 % depth of discharge, so a 100 Ah LiFePO4 pack delivers close to 80–90 Ah of usable energy.

What must be verified before substituting

Do not simply swap the battery. Three things decide whether the upgrade works:

• Charge voltage. LiFePO4 needs 14.2–14.6 V absorption and no float above 13.8 V. An old lead-acid charger pushing 14.8 V or a desulfation pulse will shorten cell life. Check the charger or solar controller has a LiFePO4 profile.
• Low-temperature charging. Charging below 0 °C damages LiFePO4 cells. For cold-climate use, specify a pack with a low-temperature cut-off or an internal heater.
• Continuous current. The BMS rating, not the cell rating, sets what the pack can deliver. A 100 Ah pack with a 100 A BMS is fine for a 1,000 W inverter; a 2,000 W inverter needs a 150 A or 200 A BMS.

How we build them

Cells are capacity- and resistance-graded before assembly, laser-welded to a nickel busbar sized for the rated continuous current, then fitted with a smart BMS that reports cell voltages, temperature and state of charge over Bluetooth, RS485 or CAN. Every pack is charged and discharged at 0.5C before it leaves the line, and the test log is filed against the serial number.

Enclosure options run from a standard ABS case in the common group sizes through to a steel case with an IP65 seal for marine and vehicle mounting. Terminals, connector type, LCD or no LCD, and the BMS communication protocol are all order-line choices, not engineering changes.