Solar Battery Storage Calculator
Solar Battery Storage Calculator — quick estimate
Size the battery bank your backup actually needs: the load it must carry, the hours it must run, and how deep the chemistry lets you discharge. Then see the indicative outlay before anyone quotes you.
Your backup requirement
Usable capacity assumes ~80% depth of discharge for LFP, ~50% for tubular lead-acid, and ~90% conversion efficiency. Cost is an editable market band — replace it with your quote.
Get a BESS design for your facility — free
Our team will size the bank on your measured load profile, pick the coupling architecture and send a storage proposal — standalone or with solar.
Your request is in
Thanks! Our team will send your battery sizing and proposal within one business day.
Indicative sizing and cost band only — not a design. Real BESS sizing follows your load profile, surge currents, autonomy policy and the inverter/PCS architecture; battery prices move with cell markets.
Questions engineers and CFOs ask
How do I size a battery for my backup load?
Battery capacity in kWh equals the load you must carry (kW) times the hours it must run, divided by the usable share of the battery. A lithium (LFP) bank is typically discharged to about 80% of nameplate and a tubular lead-acid bank to about 50%, and roughly 10% more is lost in conversion — so the bank you buy is always noticeably larger than load × hours.
Lithium (LFP) or lead-acid — which should I choose?
LFP costs more per kWh up front but is discharged deeper, lasts several times as many cycles, charges faster and needs no watering or equalising — so its cost per delivered kWh over life is usually lower. Lead-acid still makes sense for small, rarely-used backup where up-front cost dominates. For daily-cycling C&I storage, LFP has effectively won.
Does adding a battery change my solar plant design?
Yes — storage needs a hybrid or PCS-based inverter architecture, DC or AC coupling decisions, and switchgear that can island the backed-up circuits. Retrofitting storage onto a plain grid-tied plant is possible but cleaner and cheaper when the plant was wired BESS-ready in the first place, which is exactly what we design for when you tell us storage is coming.
Is a battery worth it if I already have a DG set?
For short, frequent outages a battery beats a DG on response time (instant vs seconds), noise, and cost per unit for small draws. For rare, long outages the DG usually stays. Most factories land on a hybrid: battery rides through the frequent short cuts and the DG picks up only genuine long failures — which also slashes DG running hours and maintenance.
Need an exact BOQ, rate analysis or measurement sheet?
This is a quick engineering estimate. For tendering, billing or audit, our QS & estimation team prepares an item-wise BOQ, rate analysis and a verified measurement sheet to IS / CPWD norms — backed by 15+ years and ISO 9001:2015 quality processes.