Spending a summer living aboard our old boat, Ocean Mist, taught us how important it is to have a decent set of batteries with good charging arrangements. The current electrical system on Speedwell of Rhu is a fairly standard arrangement of separate engine and domestic battery banks charging from the engine alternator or shore power. Our surveyor reported that the battery voltage was on the low side so it’s likely that the batteries are approaching the end of their natural life.
We’re planning a major upgrade to the electrical systems. As this work progresses we’ll update the information here.
Batteries and Charging
We prefer to spend time at anchor rather than in marinas so we’ll be setting up the charging systems to try to make us as independent of shore power as possible. Our initial plans include:
- New batteries, probably AGM units.
- Battery monitoring system. Accurate information about the state of the batteries helps to manage power usage and charging.
- Upgraded alternator. I’d like something in the region of 200A output, currently I’ve not decided whether a single or dual alternator installation is best. In either case the new alternator(s) will be hot rated so that they can deliver their full rated output continuously.
- Multi-stage alternator controller. Modern intelligent charge controllers are much more efficient than a simple voltage regulator.
- Wind generator. We have a Rutland 901 wind generator that we used on our previous boat. We plan to get this fitted on the mizzen. Our old boat came with an Air-X generator that had a higher rated output than the Rutland but was very noisy, so noisy that we tended not to use it. The Rutland is much quieter meaning we’re happy to leave it running most of the time so overall it delivers more charge.
- Solar. We need to decide where to put the panels but we will have some solar generating capacity. As well as adding to the overall charging capacity this will provide a float charge capability, freeing us from the need for shore power when we lay the boat up.
- New wiring. Upgrading the charging systems will place heavier loads on the boat’s wiring, so I plan to upgrade this as necessary.
Electrical Loads
The other side of the power usage equation is the amount of current taken by the electrical loads. We will be looking at the electrical systems on the boat to see where we can make upgrades that will reduce power consumption. There are some obvious places to start:
- LED navigation lights. Both more efficient and more reliable than incandescent bulbs.
- Interior lighting. LEDs and low voltage fluorescents are a good choice, halogens are definitely not. We’ll also look at providing reading lights in sensible locations to that we don’t need to run all of the cabin lights at night.
- Refrigeration. Speedwell has both engine driven and electrical compressors for refrigeration. We’ll investigate changing the electrical side to a keel/water cooled system which will be more efficient. There’s also the simple upgrade of improving the insulation around the cool box.