If you are planning a hybrid or off-grid system, the battery is one of the biggest decisions — and one of the biggest costs. The two main options are lead-acid and lithium, usually lithium iron phosphate (LFP).
Lead-acid batteries
These are the familiar tall tubular batteries used with home inverters for decades.
- Upfront cost: Lower
- Usable capacity: Best kept to about 50% depth of discharge for long life
- Life: Typically 3–6 years, depending on use and care
- Maintenance: Flooded types need distilled water top-ups; sealed (VRLA) types need less care
- Space and weight: Heavy and bulky
Lithium (LFP) batteries
- Upfront cost: Higher, though prices have been falling
- Usable capacity: Can be discharged to around 80–90% routinely
- Life: Often rated for several thousand cycles — commonly 8–10+ years with proper use
- Maintenance: Practically maintenance-free, with a built-in battery management system (BMS)
- Space and weight: Compact and much lighter
- Charging: Faster and more efficient, so more of your solar energy is actually stored
Comparing the real cost
A lead-acid bank looks cheaper, but you may replace it two or three times over the life of a solar system. Because a lithium battery gives more usable energy per cycle and lasts longer, the cost per usable unit stored over its life is often lower.
Safety
LFP chemistry is known for being more thermally stable than other lithium types. Whatever you choose, the battery should be installed in a ventilated, shaded place away from water and direct sunlight, with proper fuses and cabling.
Compatibility matters
Your inverter must support the battery type and voltage. A lithium battery should communicate with a compatible hybrid inverter so that charging is controlled correctly.
Which one is right for you?
- Choose lead-acid if your budget is tight, backup needs are small and you are comfortable with maintenance
- Choose lithium if you want long life, deeper daily use, less space and no maintenance
The bottom line
For daily solar cycling, lithium usually wins over the long term. For occasional power-cut backup on a tight budget, lead-acid can still make sense.
Tell us which appliances you need during power cuts and for how long — we'll size the right battery for you.
