Free tools

THE POWER BANK

Batteries & DC power.

The battery is the quiet accountant of a boat: every light, refrigerator, pump and screen eventually sends it a bill. Start with an energy budget, then choose chemistry, charging and protection.

LiFePO₄AlternatorsBattery monitors
Conceptual cutaway identifying cells, case and battery management. A nominal 12.8 V, 100 Ah example stores 1,280 Wh before usable-capacity and efficiency allowances. This is not a product teardown.
Slide the drawing sideways to read the full plate.
Inside a lithium house batteryConceptual cutaway identifying cells, case and battery management. A nominal 12.8 V, 100 Ah example stores 1,280 Wh before usable-capacity and efficiency allowances. This is not a product teardown.Reference: Dakota Lithium — internal BMS and battery use

THE QUESTION TO ASK

How much battery is enough for a weekend?

Lithium, charging, monitoring, and what your amp-hours actually buy.

DEEP DIVE

Start here

Batteries & DC power· 8 minReplacing a boat house battery with lithium: five compatibility checks before buyingLiFePO₄ can be a wonderful upgrade. It can also expose every shortcut in an old charging system. Do the checks in this order.Read the guide

PRACTICAL TOOL

Make the numbers behave

ENERGY TOOLBattery runtime estimatorTurn volts, amp-hours and real average watts into an estimated number of hours. See why standby loads matter.↗ELECTRICAL TOOL12/24 V wire voltage-drop explorerExplore how current, copper wire length and gauge affect calculated DC voltage drop—without pretending this sizes a safe circuit.↗