Short answer: A boat lithium conversion typically costs about $2,600–$6,000 for a 200 Ah LiFePO4 house bank and roughly $3,700–$7,700 for 400 Ah in 2026. That includes batteries at $500–$800 per 100 Ah, a DC-DC charger for the alternator, fusing and 8–16 hours of labor. A new charger or inverter adds more.
Long Beach Marine Electric connects boat owners with marine electricians who design and install lithium systems, and this guide breaks down boat lithium conversion cost line by line. Batteries are the visible expense, but a safe conversion also changes how the boat charges and protects the bank. The figures use published 2026 parts prices and Long Beach labor at $140–$200 per hour. They’re estimates, not quotes.
The cost breakdown
| Item | Basis | 200 Ah bank | 400 Ah bank |
|---|---|---|---|
| LiFePO4 batteries | $500–$800 per 100 Ah | $1,000–$1,600 | $2,000–$3,200 |
| DC-DC charger for the alternator | Victron Orion-Tr Smart from ~$160 | $160–$400 | $160–$400 |
| Fusing, cables, battery monitor | Varies by layout | $350–$800 | $400–$900 |
| Labor | 8–16 hrs at $140–$200 | $1,120–$3,200 | $1,120–$3,200 |
| Estimated total | ~$2,600–$6,000 | ~$3,700–$7,700 |
Add a lithium-capable shore charger if your current one can’t be reprogrammed. A Victron Centaur 3-bank charger starts at about $380 retail. Inverter/chargers cost more. See the marine inverter installation cost guide.
Why the charging system changes
The alternator. A lithium bank accepts charge so readily that it can hold a standard alternator at full output until it overheats. A DC-DC charger limits the current and charges the house bank from the start battery’s circuit. A smart external regulator with temperature sensing is the alternative on high-output alternators.
Chargers and solar. Lithium needs different absorption and float voltages than lead-acid. Every charge source has to be set for it.
The BMS. ABYC E-13, ratified in 2022 and effective for systems installed after July 31, 2023, requires a battery management system on lithium installations of 600 watt-hours or more, which is 50 Ah and up on a 12-volt boat. The BMS can disconnect the bank to protect it. The installation has to plan for that, so the alternator isn’t damaged and critical loads don’t go dark without warning.
What drives the price up or down
- Bank size. Batteries scale with capacity, while most other costs don’t.
- Charge sources. A boat with shore charger, alternator, solar and a generator has four sources to configure.
- Battery location. Lithium’s lighter weight helps, but cable runs and mounting can add hours.
- Reusing equipment. Programmable chargers and inverters that support lithium cut costs significantly.
- Start battery. Most conversions keep a lead-acid start battery, which avoids extra cost.
Is it worth it?
Lithium usually costs 2 to 6 times more up front than lead-acid per amp-hour. But you can use 80–100% of its capacity against about 50%, and it’s rated for 3,000–6,000 cycles against 300–800. For a boat that cycles its batteries hard, the cost per cycle ends up lower. For a boat plugged in at its slip most of the time, an AGM replacement is usually the better value. See lithium vs AGM marine batteries.
Bottom line
Budget about $2,600–$6,000 for a 200 Ah conversion and $3,700–$7,700 for 400 Ah, more if chargers or inverters need replacing. Get the system designed before buying batteries. Talk to your insurer too: see lithium batteries and boat insurance. For a design and fixed price, see boat lithium battery conversion or call (562) 374-7233.
Want a real number for your boat?
Get a same-day callback and a free estimate within 24 hours.