What Battery Bank Sizer is for

Free Ah pocket card — print it.

Battery bank sizing for off-grid power systems.

Not a second generator-authority site. Generator math lives on generator-sizer.com.

This map lists pages that exist. It is not a keyword dump and it does not treat every article as its own niche. The calculator (or the pack) is the hub. Guides sit under one pillar each.

Bank math

Usable Ah is not nameplate Ah.

• Battery bank sizer — 12/24/48 V tables, LiFePO4 80% DoD.
• How to calculate battery bank size — six steps, cabin 260.4167 Ah and van 195.3125 Ah.
• Embed the calculator — same formula, iframe snippet, credit link required.
• 12V LiFePO4 spec chart — manufacturer Ah, Wh, discharge, weight, cold charge, and cycles. Accessed Oct 6, 2026.
• Methodology and editorial standards — formula, sources, affiliate disclosure, and corrections.
• Ah pocket card — Printable nameplate vs usable.

Cabin banks

Autonomy days for a box in the woods.

• Cabin battery bank — Worked 1–5 kWh/day examples.

Van banks

Two 100 Ah batteries — until they aren't.

• Van life battery count — Weekend vs full-timer load lists.

Fuel backup

When the bank is the wrong tool.

• Generator sizing (bridge) — Wattage side — canonical depth is generator-sizer.com.

Questions

One inverter, one load, or one trolling motor. Inverter amp-hours follow Battle Born's rule of at least 100 amp-hours per 1,000 watts. Load watts are the published Honda and Champion charts. Trolling motors follow Minn Kota's 110 Ah guidance.

• What size battery bank for a 1000W inverter — 100 Ah at 12 V when one battery can carry the current.
• RTX 5090 battery bank runtime — About 75 Ah per hour for the card, 130 Ah at NVIDIA's 1,000 W power supply figure.
• Best battery for a Minn Kota trolling motor — Minn Kota's group 24, 27 and 31 rows, and how many batteries each voltage takes.
• What size battery bank for a 2000W inverter — 200 Ah at 12 V, two batteries in parallel.
• What size battery bank for a 3000W inverter — the 100 Ah per 1,000 W rule applied to a 3,000 W inverter.
• What size battery bank for a 5000W inverter — the same rule at 5,000 W, above the 3,500 W surge-limiter line.
• What size battery bank for a CPAP — Champion's 30–120 W range over an 8-hour night.
• What size battery bank for a refrigerator — Battle Born's 100 W for 5 hours, 500 Wh example.
• What size battery bank for a sump pump backup — 1,050 W running and 2,150 W starting on a 1/2 hp pump.
• What size battery bank for an RV air conditioner — 1,800 W running on a 13,500 BTU unit.
• What size battery bank for a microwave — a 1,500 W draw and 200 Ah with a 2,000 W inverter.
• What size battery for a 30 lb trolling motor — 30 A at 12 V, at least 110 Ah.
• What size battery for a 55 lb trolling motor — 50 A at 12 V, one battery, at least 110 Ah.
• What size battery for an 80 lb trolling motor — 56 A at 24 V, two batteries in series.
• What size battery for a 112 lb trolling motor — 52 A at 36 V, three batteries in series.

Guides

Wiring, storage, chargers, and the AGM count. Each one runs the same Ah formula as the calculator.

• How long a battery holds a charge — 2–3% and 4–5% per month, kept as separate manual lines.
• Series or parallel — voltage adds in series, amp-hours add in parallel, stop at 48 V.
• Maintenance, connections, and terminals — 9–11 ft-lb, and 70 in-lb on Lifeline M8 and M10.
• Lithium charger and cold charging — 14.2–14.6 V absorb, no charge under 32°F.
• Fridge and CPAP backup — 1,460 Wh for one day, about 190 Ah at 12 V.
• AGM guide — 416.7 Ah, four 105 Ah GPL-31T batteries.
• How to check a 12V battery’s capacity — Trojan’s rested-voltage table: 12.73 V is 100%, 12.10 V is 50%.
• Diesel heater battery — Air Top 2000 STC currents kept as three statements; 30.625 Ah for an 8-hour high example.

Sisters

Sourced data

• AGM vs LiFePO4 battery bank — The same load with both chemistries side by side.
• Trolling motor amp draw data — Minn Kota chart rows with a CSV you can download.

Adjacent math lives next door, not here. SolarSizer · GeneratorSizer