Atlantic Boat Repair provides professional marine electrical & battery systems services to Falmouth residents and businesses. Fast response, fair pricing, guaranteed satisfaction.
The most common electrical problem we see at Atlantic is boats with a single starting battery that is also running electronics, bilge pumps, lights, and audio. That single battery gets discharged while the boat is anchored and then struggles to start the engine at the end of the day. A properly wired dual-battery system with an automatic charging relay or battery management switch solves this entirely: one battery for starting, one battery for house loads, and an isolator that keeps them from dragging each other down.
Lithium batteries (LiFePO4) have become a realistic upgrade for many boats in the last several years. The price has come down considerably, and the advantages are significant: lithium batteries are roughly half the weight of equivalent AGM batteries, they hold their voltage much flatter under load, and they can be discharged to a much lower state of charge without damage. On a boat where every pound matters or where you are running significant electronics loads, lithium is worth considering. We will give you an honest comparison of cost versus benefit for your specific use case before you commit.
Shore power systems are the other common electrical upgrade on trailered and slip-kept boats that spend time at the dock. A proper shore power inlet with a galvanic isolator, correct wiring, and a battery charger sized for your bank means the boat is fully charged and ready when you arrive, without the risk of galvanic corrosion from stray dock current.
We also handle general marine electrical troubleshooting: parasitic draws that kill batteries overnight, corroded connections that cause intermittent problems, undersized wire runs that create voltage drop, and wiring that was added without proper fusing. Marine electrical problems are often incremental: one bad connection causes a problem, someone adds a wire to work around it, and over time the system becomes unreliable and difficult to trace. We will go through the whole system if needed and document what we find.
Dec 22, 2025 · 6 min read
After attending an industry seminar and talking with multiple battery vendors, our recommendation for most outboard-powered boats in our area has not changed: AGM batteries are the right call for the majority of boaters. Here is why, and what the alternatives look like.
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Jun 30, 2026 · 8 min read
Still love your boat but dreading every start? Learn the clear signs it's time for a boat repower, how repowering compares to continued repairs, and what the process actually involves.
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Jul 9, 2026 · 7 min read
A boat repower is more than swapping out an old motor. Modern outboards open the door to updated controls, digital gauges, integrated steering, and a helm that actually matches how you want to use your boat.
Read articleMore ways we can help in Falmouth.
Answered by our licensed technicians serving Falmouth.
Lithium (LiFePO4) makes sense if you care about weight, need deeper discharge capability, or run significant electronics loads at anchor. The upfront cost is higher than AGM, but the cycle life is considerably longer and the weight savings are real. For a typical center console or day boat, AGM is still a solid choice. We will give you a direct comparison before you decide.
A dual-battery system uses two separate batteries: one dedicated to starting the engine and one for running electronics, lights, bilge pumps, and audio. An automatic charging relay or battery management switch keeps them isolated when the engine is off so your house loads cannot drain the starting battery. It is one of the most practical upgrades on any boat.
A galvanic isolator blocks low-voltage DC current from traveling between your boat and the dock through the shore power ground wire. Without one, your underwater metals (props, trim tabs, through-hulls) slowly corrode from stray current in the marina. Any boat that spends regular time connected to shore power should have one.
A parasitic draw: a load that stays active after the master switch is off. Common culprits are bilge pump float switches, stereo memory circuits, chartplotter sleep modes, or wiring that bypasses the battery switch entirely. We test draw at the battery with everything shut off and trace the circuit from there.
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