Shop with Roton Marine

Shop With Roton Marine

Pacific Yacht Systems now sells products through our Roton Marine branded website with the same trusted service and expert product knowledge you rely on from our team. Visit Roton Marine to browse products and place your order.

Visit Roton Marine

Can I Just Drop Lithium Batteries Into My Existing Boat? PYS TECH TALK

Lithium batteries can reduce weight, deliver more usable power, and recharge quickly. But as Jeff Cote explains in this Pacific Yacht Systems Tech Talk, they are not typically a drop-in replacement for AGM or flooded batteries. The battery may fit, but the boat's charging system must be compatible with it. 

Four Things to Check 

  1. Battery charger: Your shore-power charger needs a lithium profile. If it also charges AGM engine or thruster batteries, separate charging arrangements may be needed. 
  2. Battery combiner: Do not simply parallel a lithium house bank with lead-acid banks through a conventional combiner. A DC-to-DC charger delivers a regulated, lithium-appropriate charge to the house bank. 
  3. Solar controller: Your solar controller must be programmable for the lithium battery manufacturer's recommended settings. 
  4. Alternator: Lithium batteries can draw high current for a long time, which can overheat a standard alternator. 
    1.  Use a DC-to-DC charger to limit the load, or  
    2. Pair a suitable high-output alternator with a programmable external regulator.

The Bottom Line 

A lithium conversion is an electrical-system upgrade, not just a battery swap. Map every charging source—shore power, alternator, solar, and combining equipment—before choosing your batteries. Follow all battery and equipment manufacturer instructions and applicable ABYC standards. 

Want Personalized Advice on Your Lithium Upgrade? In a one-hour, one-on-one Discovery Session, we'll review your existing electrical system, discuss your goals, and help you determine the right path forward. Book a Discovery Session with Pacific Yacht Systems → 

Watch the full video: Can I Just Drop Lithium Batteries Into My Existing Boat? 

Related: Charging Lithium Batteries with Standard Alternators  •  External Regulator Explained 

Related Content