Madrone generally doesn’t spend a lot of time tied up to a dock, but when she is in a marina it’s very convenient to be able to plug her into a shoreside electrical outlet. That way, all of the electrical systems onboard can run from shore power – it’s particularly ideal during the shorter days and often cloudier conditions of winter.
There’s usually no problem with this approach when Madrone is in the US, but traveling internationally makes things more difficult. Instead of the US system of 120V/60Hz power, other countries have 220V/50Hz, or 120V/50Hz, or 220V/60Hz power. Since the AC systems onboard Madrone are all designed for US voltage (120V) and frequency (60Hz), it can cause a problem if we were to plug the boat into a power system with different voltage or frequency.
Since we’re hoping to be able to sail Madrone to Europe one day, we need an approach that will allow us to plug the boat into European shore power and also allow us to use the onboard devices that are only designed for the US power system.
The solution we chose aboard Madrone is a fairly common one for boats that are planning to travel internationally. We installed a dedicated battery charger that can run from any input voltage (either 120 or 220V) and from any input frequency (either 50 or 60Hz). Then, we installed a large inverter that takes DC power from our battery bank and converts it to standard US AC power.
With this approach, our electrical system becomes a giant voltage and frequency converter. When we plug into shore power, the battery charger converts the incoming AC into DC, and that energy is stored in the battery bank. Then, the inverter converts the DC power back into AC power, but at the correct voltage and frequency for our onboard devices. So, any device we plug into an outlet inside the boat receives standard US power.
There are two main companies that focus on off-grid and mobile energy applications – Victron and Mastervolt. While both make good gear and offer complete solutions, their approaches differ. Victron actively embraces the open source community, making much of their source code available to all and encouraging users to tinker and develop new solutions. We like that approach, so we chose Victron gear.
The details of our installation:
- 3600VA isolation transformer
- Skylla IP65 12V/70A global battery charger
- Multiplus 12/3000/120 inverter (and charger if we’re in the US)
- Cerbo GX system monitor
- 500A SmartShunt battery monitor (we actually use two of these)
- GX Touch 50 display
