- Spanish marinas supply 230 V at 50 Hz; pedestal sockets are usually the blue round industrial type.
- A good marine charger matters as much as the batteries themselves.
- A galvanic isolator protects underwater metals when connected to shore power.
- Ask an electrician to test batteries under load, not only by voltage.
Shore power in Spain
Spain uses 230 V at 50 Hz. Marina pedestals usually have blue round industrial sockets (16 A is common, with 32 A or more for larger berths). Boats from the UK and most of Europe connect without problems; boats built for 110 V / 60 Hz markets need a transformer or converter and should be checked by an electrician before plugging in.
- Use a proper marine shore power cable of the right rating, without joins or household adaptors.
- Inspect plugs and sockets for burn marks or green corrosion; a loose or corroded pin heats up under load.
- Connect the boat end first and the pedestal end last, and disconnect in the reverse order.
Batteries
Most leisure boats have at least two banks: one for the engine and one for domestic use. Typical lifespans vary a lot by type and treatment. The main causes of early failure are being left discharged, being charged with the wrong profile and heat.
- Check that the charger profile matches the battery type (flooded, AGM, gel or lithium).
- Lithium batteries need a compatible charger, alternator regulation and a battery management system; they are not a drop-in swap.
- A battery can show a healthy voltage at rest and still fail under load. A load or capacity test tells the truth.
If the boat stays on shore power while you are away, ask for the battery voltage to be noted on every check visit. A slow downward trend shows a charger or battery problem early.
Galvanic corrosion and anodes
When a boat is connected to shore power, its underwater metals are linked through the earth wire to every other boat on the pontoon. Without protection this can eat anodes, shafts and saildrives surprisingly quickly. A galvanic isolator or an isolation transformer breaks that path. If your anodes disappear much faster than expected, ask for a corrosion check.
Common faults we see
- Corroded terminals and loose connections causing voltage drop and starting problems.
- Bilge pump float switches that stick.
- Chargers that have failed silently, leaving batteries flat after weeks away.
- DIY additions without proper fusing.
Krautic works with vetted marine electricians who can test the whole system, from shore power and chargers to batteries, instruments and navigation lights, and quote fixed prices for any work needed.