Marine Battery Bank Sizing Calculator
Amp-Hour Capacity, Battery Count, and Charging Requirements for House, Starting, and Bow Thruster Banks per ABYC E-10
Free marine battery bank planning calculator for early vessel electrical conversations. Enter daily DC load rows, select a local chemistry row, and compare a local house-bank amp-hour calculator, starting-bank CCA proxy, temperature factor, weight calculator, and battery example rows.
Outputs are source-gap planning aids only. Actual house-bank capacity, starting-battery rating, battery count, charge-source design, alternator protection, conductor and OCPD sizing, battery location, ventilation, lithium BMS behavior, ignition protection, mounting, survey acceptance, and safe installation require current ABYC standards, exact battery and engine manuals, charger/alternator product data, and qualified marine-electrician or ABYC-technician review.
Check DC wiring before current ABYC E-11 and product review
ABYC DC Wire Sizing & Voltage Drop Calculator →Check sacrificial anode assumptions before bonding and corrosion review
Sacrificial Anode Weight Calculator →Check a solar panel array before controller and battery review
Solar Array Sizing Calculator →Check charge-controller assumptions against the selected battery bank
Charge Controller Sizing Calculator →How It Works
-
Build Your Load Audit
List each DC load, then replace presets with measured current, nameplate current, duty cycle, and realistic daily run time for your vessel.
-
Select Local Chemistry Rows
Choose a planning chemistry row while treating DoD, temperature, weight, and charge behavior as manufacturer-specific source gaps.
-
Set Autonomy Assumptions
Enter the local autonomy calculator, then verify the result against actual charging access, passage plan, weather, alternator limits, solar output, and shore-power behavior.
-
Carry Source Gaps Forward
Use the export as a checklist for battery datasheets, engine starting requirements, charger settings, BMS limits, ABYC review, fusing, disconnects, ventilation, mounting, and qualified installation review.
Built For
- Cruising sailors building a preliminary load checklist before marine-electrician review
- Marine electricians gathering source-gap assumptions before specifying battery and charger hardware
- Boat builders documenting local house-load assumptions before standards and product review
- Liveaboards comparing capacity and weight screens before verifying charging and installation details
Features & Capabilities
Daily Load Audit Worksheet
Local load-entry table with common marine loads. Enter amps and hours for each load, then replace presets with measured or manufacturer data.
Local Chemistry Rows
Flooded lead-acid, AGM, gel, and lithium LFP rows are planning placeholders for DoD, temperature, and weight until exact datasheets are reviewed.
Charging Source Review Prompts
Flags that alternator, shore charger, DC-DC, solar controller, regulator, and inverter/charger compatibility require separate product review.
Source-Boundary Export
Reports carry ABYC, battery datasheet, lithium BMS, protection, ventilation, and qualified-review warnings forward.