The Offshore Voyaging Reference Site

One Simple Law That Makes Electrical Systems Easy to Understand

Yea, I know, you don’t have time for a lot of theory BS. I get that, we are all busy. But I can absolutely guarantee that you will have better results and happier cruising if you break a half hour or so free for this, and the next two chapters.

Can’t I just pay someone else to get my cruising boat electrical system up to cruising standard, you ask? I wish, but, sadly, it never ceases to amaze me how ignorant many, perhaps most, technicians around boatyards are about how electricity works. Yes, even those who have worked on boat electrical systems for years.

And the ignorance of said technicians pales into insignificance when compared to the pure unadulterated rubbish spouted by many people who sell marine electrical equipment.

And don’t even get me started on the level of BS that flies on the forums when things like batteries and charging are discussed—you could drown in the stuff.

The point being that we can waste a boatload of money and still end up with an inefficient, unreliable electrical system if we don’t have this basic knowledge.

The good news is that if we understand just a little bit of electrical theory we will immediately be able to detect the rich aroma of marine electrical BS before any harm is done. And the even better news is that this stuff is not that hard to grasp.

Let’s do it.

More Articles From Online Book: Electrical Systems For Cruising Boats:

  1. Why Most New-To-Us Boat Electrical Systems Must Be Rebuilt
  2. One Simple Law That Makes Electrical Systems Easy to Understand
  3. How Batteries Charge (Multiple Charging Sources Too)
  4. 5 Safety Tips For Working on Boat DC Electrical Systems
  5. 7 Checks To Stop Our DC Electrical System From Burning Our Boat
  6. Cruising Boat Electrical System Design, Part 1—Loads and Conservation
  7. Cruising Boat Electrical System Design, Part 2—Thinking About Systems
  8. Cruising Boat Electrical System Design, Part 3—Specifying Optimal Battery Bank Size
  9. Balancing Battery Bank and Solar Array Size
  10. The Danger of Voltage Drops From High Current (Amp) Loads
  11. Should Your Boat’s DC Electrical System Be 12 or 24 Volt?—Part 1
  12. Should Your Boat’s DC Electrical System Be 12 or 24 Volt?—Part 2
  13. Battery Bank Separation and Cross-Charging Best Practices
  14. Choosing & Installing Battery Switches
  15. Cross-Bank Battery Charging—Splitters and Relays
  16. Cross-Bank Battery Charging—DC/DC Chargers
  17. 10 Tips To Install An Alternator
  18. Stupid Alternator Regulators Get Smarter…Finally
  19. WakeSpeed WS500—Best Alternator Regulator for Lead Acid¹ and Lithium Batteries
  20. Smart Chargers Are Not That Smart
  21. Replacing Diesel-Generated Electricity With Renewables, Part 1—Loads and Options
  22. Replacing Diesel-Generated Electricity With Renewables, Part 2—Case Studies
  23. Efficient Generator-Based Electrical Systems For Yachts
  24. Battery Bank Size and Generator Run Time, A Case Study
  25. A Simple Way to Decide Between Lithium or Lead-Acid Batteries for a Cruising Boat
  26. Eight Steps to Get Ready For Lithium Batteries
  27. Why Lithium Battery Load Dumps Matter
  28. 8 Tips To Prevent Lithium Battery Black Outs
  29. Building a Seamanlike Lithium Battery System
  30. Lithium Batteries Buyer’s Guide—Part 1, BMS Requirements
  31. Lithium Batteries Buyer’s Guide—Part 2, Balancing and Monitoring
  32. 11 Steps To Better Lead Acid Battery Life
  33. How Hard Can We Charge Our Lead-Acid Batteries?
  34. How Lead Acid Batteries Get Wrecked and What To Do About It
  35. Equalizing Batteries, The Reality
  36. Renewable Power
  37. Wind Generators
  38. Solar Power
  39. Watt & Sea Hydrogenerator Buyer’s Guide—Cost Performance
  40. Battery Monitors, Part 1—Which Type Is Right For You?
  41. Battery Monitors, Part 2—Recommended Unit
  42. Battery Monitors, Part 3—Calibration and Use
  43. Battery Containment—Part 1