Products 101
Solar Battery Buying Guide India: LFP vs Tubular
Buying a solar system in India raises one confusing question fast: do I also need a battery? The honest answer for most homeowners is no. If your rooftop system is on-grid (grid-tied) and you have net metering, the grid acts as your “battery.” You send extra units during the day and pull them back at night — no expensive box on the wall needed.
But storage still makes sense for some homes. If you live where the power goes out for hours, or you want lights and a fan running through a long cut, a battery is worth a serious look. This guide walks you through when to buy storage, how to size it, and how lithium (LFP) stacks up against tubular lead-acid.
Does a grid-tied home even need a battery?
Under PM Surya Ghar: Muft Bijli Yojana, the residential rooftop subsidy, only on-grid systems get net metering and the central subsidy. These systems are designed to work with the grid, not off it. Net metering is deemed feasible up to 10 kW for homes under the Electricity (Rights of Consumers) Rules, 2020. You apply through your DISCOM after install, and approval usually takes about 15–45 days.
So most subsidised homes do not need a battery. Adding one raises your cost and does nothing for your electricity bill savings. Skip storage if:
- Your area has fairly stable power.
- Your main goal is a lower monthly bill.
- You want the fastest payback (a subsidised rooftop system pays back in roughly 3–4 years).
Consider storage if:
- You get frequent or long outages.
- You run critical loads — a medical device, Wi-Fi, a home office.
- You want backup independence, and you accept a longer payback.
Not sure which camp you are in? Getting 3 free quotes from local installers is the quickest way to see whether a battery actually fits your home and budget.
Lithium (LFP) vs tubular lead-acid
These are the two common battery choices for Indian homes. Tubular lead-acid is the older, cheaper technology you have seen with inverters for years. Lithium (LFP, lithium iron phosphate) is newer, lasts longer, and takes up less space. Here is how they compare on the points that matter.
| Feature | Lithium (LFP) | Tubular lead-acid |
|---|---|---|
| Usable depth of discharge (DoD) | High — you can use most of the rated capacity | Lower — deep draining shortens life fast |
| Cycle life | Longer life | Shorter life |
| Upfront cost | Higher | Lower |
| Size and weight | Compact, light | Bulky, heavy |
| Maintenance | Practically none | Needs periodic water topping-up |
| Best for | Long-term backup, tight spaces | Tight budgets, occasional backup |
The verified picture: lithium batteries generally have a longer life than tubular. That longer life and deeper usable capacity is what you are paying extra for. Tubular wins on sticker price but you may replace it sooner and you can use less of its rated capacity each cycle.
(All prices indicative 2026 — verify current before you buy.)
What is depth of discharge — and why it changes your sizing
Depth of discharge (DoD) is how much of a battery’s capacity you actually use before recharging. If you drain a lead-acid battery too deep, too often, its life drops sharply — so you can only safely use a portion of what is written on the label. Lithium (LFP) lets you use much more of its rated capacity per cycle.
This matters for sizing. A “2 kWh” tubular battery does not give you a full 2 kWh of usable backup — plan for less. A lithium unit of the same rating gives you more usable energy. Always size on usable kWh, not the label number.
Sizing your battery: match kWh to your backup needs
Start with what you must run during a cut, not your whole house. Add up the load, estimate the hours, and you get a rough kWh figure.
- List your backup loads. Lights, fans, TV, router, maybe a fridge.
- Estimate watts. LED lights and fans are small; a fridge is bigger.
- Decide backup hours. Two hours of cuts a day needs far less than eight.
- Convert to kWh. Watts x hours ÷ 1000 = kWh of energy per cycle.
- Adjust for DoD. Divide by usable fraction so the battery is not drained too deep.
A simple example: a Pune home runs 4 LED lights, 3 fans, a TV and a router during evening cuts. That is a modest load. A small lithium bank covers a few hours comfortably. A Jaipur home wanting to back up a fridge overnight needs noticeably more. Your installer should show these numbers on paper — if they cannot, ask again.
Our savings calculator helps you see how much a plain on-grid system saves first, so you can judge whether the extra spend on storage is worth it for your home.
Cost of ownership: look past the sticker price
The cheapest battery today is not always the cheapest over ten years. Two things decide true cost of ownership:
- Replacement frequency. A battery with shorter cycle life gets replaced sooner. Two tubular replacements can cost more than one longer-life lithium bank.
- Usable capacity. If you can only use part of a battery each cycle, you effectively paid for capacity you never touch.
Also remember the system context. Typical rooftop installs run about ₹55,000–₹75,000 per kW before subsidy (indicative 2026 — verify current; varies by brand, panel type, DCR and city). The subsidy under PM Surya Ghar is ₹30,000/kW for the first 2 kW plus ₹18,000 for the 3rd kW, capped at ₹78,000 — but that applies to the panel system, not the battery. Storage is an added cost you carry yourself.
A quick note on the scheme in 2026
New PM Surya Ghar registrations closed on 6 June 2026. By mid-2026, over 40 lakh homes were solarised and more than 1 crore had registered. If you missed it, do not rush to register now — track your status if you already applied, and watch for any next intake. Panels must be ALMM-listed with DCR cells to qualify for subsidy, so confirm your installer uses compliant DCR Mono PERC modules.
The bottom line
For most Indian homeowners on an on-grid system, net metering removes the need for a battery. Buy storage for backup, not for bill savings. If you do buy, weigh lithium’s longer life and deeper usable capacity against tubular’s lower upfront price — and size on usable kWh. Compare 3 free quotes and run the savings calculator before deciding.
Frequently asked questions
Do I need a battery with my rooftop solar in India?
Most grid-tied homes do not. Net metering lets you bank extra daytime units with the grid and draw them back later. A battery only makes sense if you face frequent or long power cuts and want backup during outages.
Which is better, lithium (LFP) or tubular lead-acid?
Lithium (LFP) generally lasts more cycles and lets you use more of its rated capacity each cycle, but costs more upfront. Tubular lead-acid is cheaper to buy but heavier, needs maintenance, and typically has a shorter life.
How do I size a solar battery to my backup needs?
List only the loads you must run during a cut, estimate their watts and the hours of backup you want, then convert to kWh (watts x hours ÷ 1000). Always size on usable kWh after allowing for depth of discharge, not the label rating.
Does the PM Surya Ghar subsidy cover batteries?
No. The central subsidy of ₹30,000/kW for the first 2 kW plus ₹18,000 for the 3rd kW (capped at ₹78,000, indicative 2026 — verify current) applies to the residential rooftop panel system only. Storage is an extra cost you pay yourself.
What does depth of discharge mean for my battery?
Depth of discharge is how much of a battery's capacity you actually use before recharging. Draining tubular lead-acid too deep too often shortens its life, so you can safely use only a portion. Lithium (LFP) allows deeper, safer daily use.
Can I still register for PM Surya Ghar in 2026?
New registrations closed on 6 June 2026. If you already applied, track your application status through your DISCOM or the portal, and watch for any future intake rather than registering fresh now.