Battery Bank Sizing Calculator | Marine Electrical System Tool
Calculate the optimal battery bank size for your boat's electrical needs. Design your marine electrical system with confidence.
Ah
days
%
V
How to Use
- Enter your daily energy usage in amp-hours
- Set desired days of autonomy (backup time)
- Adjust maximum depth of discharge (typically 50%)
- Select your system voltage (12V, 24V, etc.)
- Click Calculate to get battery bank specifications
Note: This calculation assumes standard 12V/100Ah batteries. Adjust final specifications based on actual battery specifications and manufacturer recommendations.
Frequently Asked Questions
How do I size a marine battery bank?
Calculate your daily amp-hour consumption, then multiply by days of autonomy (typically 2-3). Divide by depth of discharge (50% for lead-acid, 80% for lithium) to get the required bank capacity.
Should I use lithium or AGM batteries on my boat?
Lithium (LiFePO4) batteries are lighter, last 3-5× longer, and provide usable capacity down to 80% DOD. AGM batteries are cheaper upfront but heavier and limited to 50% DOD for longevity.