Lithium Battery

Lithium Battery for Solar: Complete Buying Guide
Choosing the right lithium battery for your solar system decides how much backup you get, how long the battery lasts, and how much you spend over 10 years. This guide explains what matters when buying a lithium battery and helps you pick the right size.

LiFePO4 vs Lead-Acid: Real Cost Over 10 Years
The upfront price of a lead-acid battery is lower than lithium. But the total cost over 10 years tells a different story.
Lead-Acid Battery

Typical life: 3–5 years
You will need to replace it 2–3 times in 10 years
Needs regular water topping and maintenance
Heavy — a 100Ah lead-acid battery weighs 30–35 kg
Works at about 50% depth of discharge (you can only use half the capacity)

LiFePO4 Lithium Battery

Typical life: 8–10 years with 3000+ charge cycles
No replacement needed in most cases
Zero maintenance — no water topping, no corrosion
Lightweight — a 100Ah LiFePO4 battery weighs 24–25 kg
Works at 80–90% depth of discharge (you use almost full capacity)

The math: A lead-acid battery typically needs 2–3 replacements over 10 years. A LiFePO4 battery lasts the full 10 years on a single purchase. Even if the upfront cost of lithium is higher, you avoid buying 2–3 replacement batteries — which means lower total cost and less hassle over the life of your solar system.

How to Size Your Battery (Ah Calculation)
Battery capacity is measured in Ampere-hours (Ah). Here is how to calculate what you need.
Formula:
Battery Ah = (Load in Watts × Backup Hours) ÷ (Battery Voltage × 0.8)
The 0.8 factor accounts for 80% depth of discharge — you should not drain a lithium battery completely.
Worked Example:
You want to run a 500W load for 8 hours of backup on a 48V system.
Battery Ah = (500 × 8) ÷ (48 × 0.8)
Battery Ah = 4000 ÷ 38.4
Battery Ah = 104Ah
So you need a 100Ah 48V lithium battery for this setup.
Quick Reference:

100Ah 12.8V → good for small 12V backup systems, lights, fans, phone charging
100Ah 25.6V → suits 24V inverters for 2–3kW home systems
100Ah 51.2V → fits 48V inverters for 5–10kW home and commercial systems

What a Good BMS Must Do
Every lithium battery needs a Battery Management System (BMS). It protects the battery and your appliances.
Overcharge Protection
Stops charging when the battery is full. Without this, the battery can overheat and get damaged.
Deep Discharge Protection
Prevents the battery from draining below safe levels. Draining a lithium battery too low reduces its life.
Temperature Protection
Shuts off charging or discharging if the temperature goes too high or too low. This is important in Indian summers where temperatures can cross 45°C.
Short Circuit Protection
Cuts off power instantly if there is a short circuit. This prevents fire hazards.
Cell Balancing
Makes sure all cells inside the battery charge equally. Uneven charging reduces battery life and capacity.
All Nexus lithium batteries come with a smart BMS featuring active cell balancing and built-in temperature sensors. Display models additionally show the live life-cycle count on screen, so you always know your battery’s health. Up to 16 Nexus batteries can be connected in parallel, letting you start small and expand your storage as your needs grow.

Nexus Lithium Battery Range Compared

Model
Capacity
Voltage
Chemistry
BMS
Cycle Life
Warranty
MRP (Incl. GST)

100Ah 12.8V Lithium PO4 Battery
100Ah
12.8V
LiFePO4
Smart BMS
3,500 cycles
5 years*
₹27,187.20

100Ah 12.8V Lithium Battery
100Ah
12.8V
LiFePO4
Smart BMS
5,000 cycles
5 years*
₹27,187.20

100Ah 12.8V Lithium Battery (DEVSOL)
100Ah
12.8V
LiFePO4
Smart BMS
5,000 cycles
15 years*
₹31,624.00

100Ah 25.6V Lithium Solar Battery
100Ah
25.6V
LiFePO4
Smart BMS
3,500 cycles
5 years*
₹54,374.40

100Ah 25.6V Lithium Battery
100Ah
25.6V
LiFePO4
Smart BMS
5,000 cycles
5 years*
₹54,374.40

100Ah 51.2V Lithium Battery with Display
100Ah
51.2V
LiFePO4
Smart BMS with LCD display
5,000 cycles
5 years*
₹108,748.80

100Ah 51.2V LiFePO4 Pro Battery with Display
100Ah
51.2V
LiFePO4
Smart BMS with LCD display
6,500 cycles
5 years*
₹135,700.00

Frequently Asked Questions
How long does a LiFePO4 battery last?
A LiFePO4 battery typically lasts 8–10 years with 3000 or more charge cycles. This is 2–3 times longer than a lead-acid battery. Actual life depends on usage patterns, temperature, and depth of discharge.
What warranty comes with Nexus lithium batteries?
Nexus lithium battery warranty depends on the product series: ECO Plus series carries a 5-year warranty, Nexus Premium series carries a 5-year warranty, and DEVSOL series carries a 15-year warranty*. Warranty terms and conditions apply.
Can I use a lithium battery with my existing inverter?
Most modern hybrid inverters support lithium batteries. Check your inverter’s battery voltage (12V, 24V, or 48V) and match it with the correct lithium battery voltage. Contact Nexus Solar Energy to confirm compatibility before purchasing.
What is the difference between 12.8V, 25.6V, and 51.2V lithium batteries?
The voltage must match your inverter. A 12.8V battery works with 12V inverters. A 25.6V battery works with 24V inverters. A 51.2V battery works with 48V inverters. Using the wrong voltage will damage the inverter or battery.
Are lithium batteries safe for home use?
Yes. LiFePO4 lithium batteries are one of the safest battery chemistries available. They do not catch fire easily, do not contain toxic materials, and have built-in BMS protection against overcharging, short circuits, and temperature extremes.
How do I calculate backup time for my load?
Divide the battery’s total energy (Ah × Voltage) by your load in watts. For example, a 100Ah 51.2V battery stores 5,120Wh. If your load is 500W, backup time is approximately 10 hours (5,120 ÷ 500). Actual backup will be slightly less due to inverter losses.
Where can I buy Nexus lithium batteries?
Visit nexussolarenergy.in/locator/ to find your nearest dealer, or contact Nexus Solar Energy directly via WhatsApp at +91 9258288616 for product guidance and pricing.
Warranty terms and conditions apply.
Read: Lithium Battery Manufacturer in India — Inside Nexus Solar Energy’s 15-Year* Warranty