Off-Grid Solar & Battery Sizing

Size your DIY system with a free, vendor-neutral calculator. Daily loads, battery bank, solar array, and 2026 AU rebate estimate.

⭐ Free to use

Size My System

Free to use • No registration • Vendor-neutral

Why WattSizing?

Trusted for accurate, DIY off-grid solar and battery sizing

Accurate System Sizing

Daily load calculator, peak sun hours, and battery bank sizing at 12V, 24V, and 48V.

Vendor-Neutral

Lithium (LiFePO4) and Sodium-ion options with 90% DoD. No brand lock-in.

2026-Ready

Australia STC rebate estimate with factor 6.8 and tapering for May–Dec 2026.

Solar & Energy Tips

Insights on off-grid solar, battery storage, and DIY system design

Best Batteries for Off-Grid Solar: LiFePO4 vs Lead Acid vs Saltwater

Choosing the right battery is critical for off-grid success. We compare LiFePO4, Lead Acid, and Saltwater batteries based on cost, lifespan, and performance in 2026.

12 min read min read

Off-Grid vs Grid-Tied vs Hybrid Solar: Which System Fits Your Goal?

Compare off-grid, grid-tied, and hybrid solar: how they work, pros and cons, and when to choose each.

6 min read

Cost of Off-Grid Solar in 2026: Realistic Budgeting

How much does it really cost to go off-grid in 2026? We break down the prices for small, medium, and large systems, including hidden costs.

12 min read min read

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