Switching to Lithium Batteries on a Yacht: Saving Space, Money, and Powering a Sustainable Journey

Case Study: Simon Hardaker and Cassini — 10,000 Nautical Miles Across the Atlantic

Simon Hardaker’s transatlantic voyage aboard Cassini—covering over 10,000 miles and two crossings of the Atlantic Ocean—proves just how transformative lithium battery upgrades can be for modern cruising yachts.

Why Switch from AGM to Lithium (LiFePO₄)?

• AGM batteries degrade quickly and offer only ~50% usable capacity.
• Lithium batteries provide ~90% usable capacity and last 3–4 times longer.
• They are lighter, more compact, and offer better long-term value.

What Was Upgraded or Added?

• Victron Smart Charger for lithium compatibility
• DC-DC Charger to prevent alternator overheating
• Thicker gauge cables to safely handle higher current
• Battery Management System (BMS) with mobile app for monitoring and control

Real-World Results:

• Over 10,000 miles sailed, including two Atlantic crossings
• Minimal engine use for battery charging
• Easy future expansion—just connect more batteries in parallel
• Total cost for the full system: under £3,500

This case highlights how switching to lithium not only improves energy efficiency but also enhances comfort, reliability, and sustainability at sea.

Source: Yachting Monthly