Port Credit Marine Survey
& Yacht Delivery
5. Power Management

You can add huge battery banks to ensure all the conveniences of home but the bigger the bank, the bigger the charging source must be. 2800amps in a house bank is great but it will take you a week to charge them with that 55amp alternator that in reality puts out 20amps if you are lucky. This is a complex issue and can be made more so with the addition of an inverter. Give serious consideration to hiring an ABYC Certified Marine Electrician to review your system well in advance of casting off. This will not only save money in the long run but there are significant safety issues to be considered too.

Power management is a daily and sometimes hourly project when on the hook and one key element is knowing how much you have in your batteries.  We have an E-meter that tells us current amperage draw, time remaining at that draw, amp hours used, voltage and a few other critical bits of information. If your batteries are more than a few years old, have them load tested before you depart. Just because they show 13.2V when hooked up to a shore powered charger does not mean they will last with the constant use they will be subjected to.

We have found that 6V golf cart batteries in series/parallel take a tremendous amount of abuse and last a long time. Having your regulator set up to charge your batteries while tied to the dock at home is a very different matter than when cruising. A programmable regulator will allow you to adjust for high or lower charge rates depending on your cruising style.

On the way south, power management is not such a big issue as running almost every day keeps your batteries up but when stuck on the hook for a few days due to weather or a few weeks once in the Bahamas, it becomes more difficult.

Many sailboats have elaborate solar panel rigs that cost a fortune and when you consider
Laura at Manjack Key,in the Abacos
their miserable output they are probably the most expensive amps you will ever buy. Wind generators are much more efficient but many send a hum through the boat but winter winds in the Bahamas are pretty much constant. Our 2000watt gasoline generator on the flying bridge in a dedicated box complete with exhaust outlet is fitted with a 30amp outlet into which we plug our shore power cord. Our 6 golf cart batteries give 3 - 4 days power and then we run the genny for about 4hrs. to completely recharge them.

Many cruisers are now carrying these portable genny’s and when you consider cost per amp they are by far the most efficient means of topping up your batteries.

Unfortunately I have seen too many sailboats with these units running in the cockpit…..can you spell carbon monoxide ? Put it way up at the bow and don’t forget to close that forward hatch. I read of one incident where a guy was working in his cockpit with a genny running on the dock next to his boat, he was found dead ! CO is buoyancy neutral and will go wherever the breeze takes it.

Chapter 6. Ground Tackle and How to Use it.

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