Power source

Balmar XT-250 (Lithium)

High-output 250A alternator designed for sustained lithium charging with an external regulator (Wakespeed WS500 / Balmar MC-614). Wire and fuse for sustained near-rated output.

The reference run on this page is 3 m one way, sized against ABYC E-11. Your own run will differ, and the canvas sizes that one.

Wiring diagram

How the XT-250 250A is wired.

The drawing shows where the feed, the return and the fuse land on this part. The starter uses the same reference circuit and sizing assumptions. Read the installation notes for manufacturer requirements before adapting the runs.

Balmar XT-250 (Lithium) wiring diagram, 95 mm² (3/0 AWG) positive feed protected by a 350 A fuse and a matching negative return between the 12 V battery bank and the unit.
Open starter in Crimp

Build it out

Build the system it goes in.

Open the canvas with XT-250 already placed, then add your batteries, charging, distribution and loads around it.

Every cable you draw there is sized against ABYC E-11, from the same tables as the reference on this page.

Technical reference

Specs, terminals and the parts around them.

The catalog facts for this part, which terminal takes what, and the hardware you'll want around it. Check the nameplate on your own unit before you order.

Catalog specification

Rated output
250 A
Planning charge current
180 A

3 m reference run

12 V system

Wire
95 mm² · 3/0 AWG
Fuse
350 A
Design current
250 A
Voltage drop
2.3%

Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The design current is the unit's rated output. The length is one way; voltage drop includes an equal-length return. The shared starter uses 3.048 m (10 ft) runs unless a shorter run is stated. These are example assumptions for you to adapt to your own installation.

Supporting parts

  1. 6 m total of 95 mm² (3/0 AWG) marine cable
  2. Terminations for 95 mm² cable, matched to the equipment's screw terminals, leads or studs
  3. 350 A fuse and holder on the positive run
  4. Heat-shrink, strain relief and terminal boots sized to the cable

Check stud sizes, fuse type, run length and how warm the space gets against the gear you actually have before you order.

Terminal map

Catalog connection points, current direction and planning limits. Check the manufacturer's pinout and connector ratings before installation.

B+

pos

positive · output

300 A

GND

neg

ground · bidi

300 A

Method & provenance

What is known, assumed and computed.

The manufacturer publishes some of these numbers and Crimp works out the rest. It's worth knowing which is which.

From the maker

What the catalog says

Manufacturer, model, ratings and which terminal does what come from the catalog. A newer revision, or the nameplate on the unit in your hand, can say something different — when it does, the nameplate wins.

ABYC E-11

What Crimp worked out

Sized against ABYC E-11. Boats built to UK or EU rules answer to ISO 13297 — check these figures against it before you build. The run length and the current above are what drive the result. Crimp doesn't know how warm your space gets; draw the cable inside an engine-bay zone on the canvas and it sizes for the heat.

Read how the sizing works

Next step

Draw the XT-250 250A into your own system.

It lands on the canvas already placed. Add what it connects to, and every run gets its wire and fuse as you draw.