LiFePO4 batteries for reliable energy storage

LiFePO4, also called lithium iron phosphate or LFP, is a rechargeable lithium chemistry used in solar storage, off-grid systems, motorhomes, boats, mobility equipment, backup power and custom battery banks. This category includes complete batteries and individual prismatic cells; they are not interchangeable products and require different levels of system integration.

Complete batteries or individual cells?

How to size a LiFePO4 battery

Start with energy rather than amp-hours alone. Multiply each appliance power in watts by the number of hours it operates per day. Add the results to obtain daily watt-hours, then allow for inverter and wiring losses, the required reserve and the number of days of autonomy.

Nominal energy (Wh) = nominal voltage (V) × capacity (Ah). A 12.8V 100Ah battery stores about 1,280Wh nominal. A 25.6V 100Ah battery stores about 2,560Wh, so batteries with the same Ah rating can contain very different amounts of energy.

Example for a small off-grid installation

• 60W refrigerator average for 8 equivalent hours: 480Wh.
• 20W lighting for 5 hours: 100Wh.
• 40W electronics for 4 hours: 160Wh.
• Total before losses and reserve: 740Wh per day.

The final battery should not be chosen from 740Wh alone. Consider inverter efficiency, seasonal production, charging time, days without solar input and the operating limits of the exact battery.

Choosing 12V, 24V or 48V

Higher system voltage reduces current for the same power. This can make cable sizing and voltage drop easier in medium and large installations. Keep 12V for compatible low-power equipment and existing mobile systems; consider 24V or 48V for larger inverters and storage banks after checking every charger, controller, inverter and DC load.

BMS, charger and inverter compatibility

A Battery Management System monitors and protects the battery at cell level and controls charging or loads when operating limits are reached. Complete batteries may incorporate a BMS, while individual cells require a correctly selected external BMS. In both cases, confirm continuous and peak current against the inverter, motor or other loads.

Use a charge profile approved for the exact LiFePO4 model. A charger being labelled 12V or 24V is not sufficient: charge voltage, absorption behaviour, temperature limits and communication requirements must match. Do not assume every AGM or GEL charger, alternator regulator or solar controller is compatible.

Safe installation checklist

• Fit a correctly rated fuse close to the battery positive terminal.
• Size cables and lugs for current, cable length and permissible voltage drop.
• Secure batteries and cells in a protected enclosure with insulated terminals.
• Check terminal polarity and mechanical dimensions before replacement.
• Confirm whether the exact model permits series or parallel connection.
• Do not charge below the temperature limit stated in the product documentation.
• For loose cells, use matched cells, a suitable BMS and the specified mechanical retention.

Applications

Residential solar self-consumption

Storage should be matched to daily surplus production, evening consumption, inverter compatibility and the desired level of backup. Residential systems may also require communication between the BMS and inverter; check the approved compatibility list before purchase.

Off-grid solar installations

Autonomy is normally the critical factor. Calculate winter consumption and expected solar production, not only an annual average. Allow for several low-production days where the installation depends entirely on the battery bank.

Motorhomes, campervans and boats

Check alternator charging, DC-DC charger settings, shore charger, solar controller, ventilation, mounting and cable protection. High-power inverters can create very high DC currents in a 12V system.

Custom prismatic-cell packs

Prismatic cells are components for a battery system, not finished drop-in batteries. Pack design must include a BMS, enclosure, busbars, overcurrent protection, isolation, service disconnect and appropriate testing.

Frequently asked questions

Can a LiFePO4 battery replace an AGM or GEL battery?

Sometimes, but it is not an automatic replacement. Check charger voltage, terminal layout, dimensions, BMS current capability and the equipment manufacturer's requirements.

Can LiFePO4 batteries be connected in series or parallel?

Only when the exact model permits it. Batteries combined in a bank should have the same model, capacity, age and state of charge, and the installation must follow the manufacturer's limits.

Is Bluetooth the same as a BMS?

No. Bluetooth is a monitoring interface. The BMS is the protection and control system. Available readings and protective limits depend on the exact product.

How many cells are needed for a 48V battery?

A typical LiFePO4 bank uses sixteen 3.2V cells in series for 51.2V nominal. The BMS, inverter and charger must all be selected for that configuration.

Do LiFePO4 batteries need maintenance?

They do not require electrolyte topping up, but the installation still needs periodic checks of terminals, cables, fuses, mounting, charger settings and battery status.

Use the product filters to compare voltage, capacity, dimensions, terminals and monitoring options. If you need help, send us the system voltage, daily energy use, maximum load power and charging sources so we can check the most suitable configuration.