Diagnostic Guide

Marine Battery Won't Hold Charge

If your battery dies between weekend trips, the problem is almost always one of three things.

If your battery dies between weekend trips, the problem is almost always one of three things.

What to Check

1

Parasitic drain

Bilge pump, stereo memory, refrigerator, or alarm draws current 24/7. Even small drains kill batteries between trips.

2

Sulfated battery

Lead-acid batteries that sit at low voltage for weeks develop sulfation and lose capacity. Most batteries are toast at 4–5 years in the Bay.

3

Failed alternator / charger

If the battery isn't being properly charged, it'll never hold a charge no matter how new.

When to Call Us

Battery testing and parasitic-drain measurement is a 30-minute slip-side service. We'll find the cause and recommend the right fix — lead-acid replacement, AGM upgrade, or full lithium conversion.

Services That Fix This

Ready to Get Your Boat in Prime Condition?

Bring your boat to our covered shop in San Rafael for full-service repair, maintenance, paint, and refits. Call (415) 524-5194 or send a message — we respond same day.

Call (415) 524-5194