Cruising Boat Electrical System Design, Part 2—Thinking About Systems

In the last chapter we thought about what our electrical consumption was going to be and (hopefully) wrote those numbers down for both sailing offshore and at anchor. Next we need to add in any other big loads that I did not deal with in the last chapter. Two that come to mind are 12/24 volt DC watermakers and furnace type heaters like those from Eberspächer (Espar) and Webasco. (If you are wondering why I didn't mention these two before, the reason is highly technical...I forgot. Sorry). That said, my senior moment is actually a good thing, because watermakers give us another chance to think about smart management of all loads, so that we can build an electrical system that does the job of supporting happy and comfortable cruising without requiring a really silly number of batteries. Let's look at that:

  1. One Simple Law That Makes Electrical Systems Easy to Understand
  2. How Batteries Charge (Multiple Charging Sources Too)
  3. How Hard Can We Charge Our Lead Acid Batteries?
  4. Cruising Boat Electrical System Design, Part 1—Loads and Conservation
  5. Cruising Boat Electrical System Design, Part 2—Thinking About Systems
  6. Cruising Boat Electrical System Design, Part 3—Specifying Optimal Battery Bank Size
  7. The Danger of Voltage Drops From High Current (Amp) Loads
  8. How Batteries Get Wrecked and What To Do About It
  9. 11 Steps To Better Battery Life
  10. 10 Tips To Buy And Install A Live-aboard’s Alternator
  11. Stupid Alternator Regulators Get Smarter…Finally
  12. Smart Chargers Are Not That Smart
  13. Equalizing Batteries, The Reality
  14. Battery Monitors, Part 1—Which Type Is Right For You?
  15. Battery Monitors, Part 2—Recommended Unit
  16. Battery Monitors, Part 3—Calibration and Use
  17. Do You Need A Generator?
  18. Efficient Generator-Based Electrical Systems For Yachts
  19. Battery Bank Size and Generator Run Time, A Case Study
  20. Battery Options, Part 1—Lithium
  21. Battery Options, Part 2—Lead Acid
  22. Lithium Ion Batteries Explained
  23. Should Your Boat’s DC Electrical System Be 12 or 24 Volt?—Part 1
  24. Should Your Boat’s DC Electrical System Be 12 or 24 Volt?—Part 2
  25. Q&A—Are Battery Desulphators a Good Idea?
  26. Renewable Power
  27. Wind Generators
  28. Solar Power
  29. Hydro Power
  30. Watt & Sea Hydro Generator Review

John was born and brought up in Bermuda and started sailing as a child, racing locally and offshore before turning to cruising. He has sailed over 100,000 miles, most of it on his McCurdy & Rhodes 56, Morgan's Cloud, including eight ocean races to Bermuda, culminating in winning his class twice in the Newport Bermuda Race. He has skippered a series of voyages in the North Atlantic, the majority of which have been to the high latitudes. John has been helping others go voyaging by sharing his experience for twenty years, first in yachting magazines and, for the last 18 years, as co-editor/publisher of AAC.

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