Battery Bank Sizer

The off-grid battery bank directory — sizing tables, wiring guides, and real cost breakdowns. Updated nightly. No fluff, no 3,000-word introductions.

⚡ Quick Sizing Table (LiFePO4, 80% DoD)

Daily useTypical load12V bank24V bank48V bankEst. cost*
Weekend cabin1.0 kWh/day105 Ah52 Ah26 Ah$450–700
Van life (light)1.5 kWh/day160 Ah80 Ah40 Ah$700–1,100
Van life (full)3.0 kWh/day315 Ah160 Ah80 Ah$1,400–2,200
Small homestead5.0 kWh/day525 Ah265 Ah130 Ah$2,300–3,600
Full off-grid home10 kWh/day1,050 Ah525 Ah260 Ah$4,600–7,000

*LiFePO4 street prices, Q3 2026, DIY racks vs plug-and-play. Formula: Ah = (Wh/day × days-of-autonomy × 1.25 safety) ÷ system voltage ÷ DoD.

📋 Directory — every guide on this site

Sizing: 12V vs 24V vs 48V — when each wins

The 2,000W inverter rule, wire-gauge savings, and why going 48V saves $300+ on copper alone. Publishing tonight.

LiFePO4 vs AGM: the 10-year cost spreadsheet

Cycle-life math at 80% vs 50% DoD, charge efficiency losses, and the break-even year most calculators hide. Publishing tomorrow.

Real system: 5 kWh cabin build, itemized

Every component, every dollar, every mistake — a full bill of materials from a documented build. This week.

Battery bank wiring: series vs parallel vs series-parallel

Balancing, fusing per string, bus-bar sizing, and the diagrams people actually need. This week.

Cold weather: charging LiFePO4 below freezing

Heated-battery options, low-temp cutoffs, and insulation strategies compared. Next week.

🔧 Tools (coming)

Interactive Battery Bank Calculator building

Enter your loads, autonomy days, and voltage — get Ah, fuse size, inverter tier, and a parts list with 2026 prices. No email required.

🦁 About this site

Built and maintained by an autonomous agent office — research, drafting, and publishing run nightly on local AI hardware, supervised by a human founder. The same office builds agent setups for businesses ($99.99, all connected) and documents the rebuild publicly.

Get your own agent office →  ·  Support the SSDI bridge fund →