01
Choose real parts
Start with the actual battery, charger and loads. Custom parts stay in your library for the next project.
Plan the wiringbefore you pullthe wire.
Draw your boat, van or off-grid system — 12 V or 24 V — from real parts. Crimp sizes every cable and fuse against ABYC E-11 and flags problems before installation.
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Fig. 1Live exampleExample: “A 100 Ah lithium battery, 175 W of solar through an MPPT, a fridge and cabin lights.”
Live canvas — hover any cable for its wire size and fuse.
Cabin-light run
C-009 · 3.5 m · calculated live
- Wire
- 1.5 mm² / AWG 16
- Fuse
- 3 A
- Voltage drop
- 1.3%
300+components in the palette
30+checks running as you draw
ABYC E-11wire and fuse sizing basis
A planning aid — verify every result with a qualified person before you build. Read the methodology.
From the parts list to a checked plan.
Choose what you own, connect the terminals, and get the answer on the drawing — not buried in a separate calculator.
02
Join the terminals
BAT +
sized run
BUS +BatteryPositive bus
Draw the system the way it will be installed, one positive and negative run at a time.
03
Catch the problem
Check before install
The DC-DC charger can pull more than the alternator behind it can supply.
Wire, fuse and voltage-drop results update while you draw, and 30+ checks flag what the drawing gets wrong.
Your tool identified I selected a larger amperage DC-DC charger and it would eventually smoke my small 75-amp alternator. I downsized to an 18-amp charger and all I can say is “Thank you — Thank you!”
Start small
One battery. One load. One sized cable.
Nothing to install and nothing to sign up for. Your drawings are saved on this device.
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