Lithium-ion vs Lead Acid Batteries for Solar

The Great Battery Debate

When setting up an off-grid or hybrid solar system, the battery is often the most critical (and expensive) component. Historically, Lead-Acid tubular batteries have ruled the Indian market. However, Lithium-ion (specifically LiFePO4) is rapidly taking over.

Depth of Discharge (DoD)

A standard 150Ah Lead-Acid battery has a DoD of around 50%. This means you can only safely use 75Ah before needing to recharge it, or you risk damaging the battery. A Lithium-ion battery offers a DoD of 80% to 95%, meaning a much smaller capacity battery can provide the same usable backup power.

Lifespan and Warranty

Lead-acid batteries typically last 3 to 5 years (500-1000 charge cycles). Lithium-ion batteries can easily last 10 to 15 years (3000 to 5000 cycles). While the upfront cost of Lithium is higher, the cost-per-cycle is drastically lower over the system's lifespan.