Fall boat winterization is the most consequential maintenance event of the boating year. Decisions made in October determine whether the April splash goes smoothly or reveals months of preventable damage. Battery preparation is the highest priority component because battery failures are the most common and most completely preventable spring issue.
The Battery Winterization Sequence
Step 1: Run the WaveCharge onboard charger for a complete ISM charge cycle on all batteries before winterization begins. Starting the storage period at full charge gives each battery the maximum buffer against self-discharge.
Step 2: If shore power will be available at the storage location, verify the shore power connection is active and all WaveCharge bank indicators are showing operating status before leaving the vessel for winter.
Step 3: If shore power will NOT be available: disconnect each battery's negative terminal to eliminate all parasitic loads. Remove batteries to a climate-controlled storage location if temperature extremes are expected. Connect individual Battery Tender chargers to each battery at the storage location.
Step 4: During winter storage, perform a monthly visual check of charger indicators. A WaveCharge showing green maintenance lights on all banks is operating correctly. Any error indication or unexpected amber/red light warrants investigation.
Step 5: Before spring launch, reconnect all batteries and run a full ISM charge cycle. Test each battery with a multimeter — a healthy battery after winter maintenance should read 12.6V or above. Test with a load tester before relying on the battery for the season.
Battery Tender WaveCharge 4-Bank 12 AMP
Battery Tender WaveCharge Pro 2-Bank 20 AMP
Battery Tender Plus 12V 1.25A — Individual Battery Off-Site Winter Storage
