# What a Lithium Conversion Looks Like, Start to Finish | Long Beach Marine Electric > An illustrative walkthrough of a typical boat lithium conversion, from energy audit to commissioning, so you know what to expect before you book. URL: https://longbeachmarineelectric.com/blog/what-a-lithium-conversion-looks-like/ Walkthrough # What a Lithium Conversion Looks Like, Start to Finish By Long Beach Marine Electric · October 6, 2026 [Long Beach Marine Electric](/) put together this walkthrough of a typical boat lithium conversion so you know what the work involves before booking one. **This is an illustrative example, not a customer story.** The boat, figures and steps describe a common scenario, a 36-foot cruising sailboat that anchors out near Catalina a few weekends a year, and every real job differs. ## Step 1: The energy audit The owner lists what runs away from the dock: a 12 V fridge, chartplotter and instruments, autopilot underway, LED cabin lights, an anchor light, and phones and laptops. Over a typical day at anchor, that comes to roughly 120–150 Ah. The existing 2 × 100 Ah AGM bank gives only about 100 Ah usable, which is why the batteries were flat by the second morning. **Design target:** about 200 Ah of usable capacity. That means a 200–250 Ah LiFePO4 bank, since lithium can use 80–100% of its rating. ## Step 2: Surveying the charging sources - **Shore charger:** an older lead-acid-only model. It needs to be replaced with a lithium-capable charger. - **Alternator:** a stock 55 A unit with an internal regulator. A **DC-DC charger** will limit the current to protect it. - **Solar:** a 100 W panel with a PWM controller. Upgrading to an MPPT controller with a lithium profile is a cheap improvement. - **Start battery:** kept as AGM, charged from the alternator directly. The DC-DC charger feeds the house bank from it. ## Step 3: The written design The electrician specifies the batteries, the DC-DC charger, the new shore charger, a battery monitor, main fusing rated for lithium fault current, cable sizes, and how the system behaves if the battery management system disconnects the bank. That design, and ABYC E-13 (ratified in 2022, applying to systems installed after July 31, 2023), drive the fixed price. Batteries alone run about $500–$800 per 100 Ah in 2026. See the [lithium conversion cost guide](/guide/lithium-conversion-cost/) for the rest of the bill. ## Step 4: Installation (typically one to two days) 1. Remove the AGM house batteries and clean the battery compartment. 2. Mount the lithium batteries securely, with cables kept short and protected. 3. Install main fusing and a disconnect close to the bank. 4. Install the DC-DC charger between the start and house circuits. 5. Replace the shore charger and set its lithium profile. 6. Swap the solar controller for an MPPT unit and set its lithium profile. 7. Install the battery monitor shunt and display. ## Step 5: Commissioning Every charge source is tested one at a time: shore charger, alternator through the DC-DC charger, and solar. Charge current and voltage are measured at the bank, and the BMS warning and disconnect behavior is checked. Settings are recorded in an installation summary the owner keeps for the insurer and future surveys. ## What the owner ends up with About twice the usable energy of the old bank at under half the weight, faster charging from the engine and solar, and a bank rated for thousands of cycles instead of hundreds, plus paperwork showing it was done to E-13. Thinking about a conversion? See [boat lithium battery conversion](/lithium-battery-conversion/) or call **(562) 374-7233**. ## Sources - [Panbo: ABYC ratifies E-13](https://panbo.com/abyc-ratifies-e-13-their-first-lithium-battery-standard/) - [LiTime: deep-cycle marine battery prices (Jul 2026)](https://www.litime.com/blogs/buying-guides/deep-cycle-marine-battery-prices-cost-comparison) Free estimate Two quick steps. A callback the same day. Faster by phone: [(562) 374-7233](tel:+15623747233) Get a marine electrician to your slip Same-day dockside callback · Free estimate within 24 hours [Call (562) 374-7233](tel:+15623747233) [Get a Free Estimate](/contact/)