Boating Lessons Learned

Boating Lessons Learned – 6 volt golf cart batterries carefully wired together to supply 12 volts have been a good choice for me over the years to supply power to our boat.

6 volt Golf Cart Batterries are:
– less expensive per amp-hour of storage capacity
– constructed to survive repeated deep discharges
– individually smaller and safer to handle. BIG PLUS.
– wired in series pairs to supply 12 volts

One of my good friends has been considering replacing his standard 12 volt deep cycle batteries with a single big 4D battery to supply power to an inverter.  As we discussed the pros and cons our converastion naturally drifted to other options such as banking together two 6 volt golf cart batteries wired in series to provide 12 volts to the system.  I have found them to be less expensive per amp-hour of capacity, have lasted much longer, and are easier to handle than the big 4Ds or 8Ds.

Consider the following:

The typical big box store 4D battery is not a deep cycle and if you do locate A true deep cycle 4D it will likely be expensive.  Even the standard duty models run around $190.  But I am convinced that I really need a deep cycle type since I will be deeply discharging these batteries and I will need a battery that can survive this sort of duty.   My experience has been that A standard duty battery will last about half as long as a golf cart battery in the service results in periodic deep battery discharge.

My experience has been that deep cycle golf cart batteries are on the order of half the price of a deep cycle 4D or 8D per amp-hour of storage capacity but I remain open minded to the broad range of options. My approach To finding a good battery value is:
– determine the amount of energy storage capacity that I need
– call the discount battery houses looking for blemished models
– gather data on the various available battery sizes, storage capacity, and price
– determine the price per amp hour of capacity
– choose the best value battery that fits in space available

I first determine how much battery capacity I need. The quick way that I do this is to turn on my pieces of equipment that I typically run when at anchor and just look at the DC amp meter on my power panel. Multiply the amps drawn by the hours I will likely be at anchor and multiply this by 2. The result is the number of amp-hours of battery storage that I believe is needed.

When shopping for discount batteries I make sure that I ask if they have discounted blemished batteries available. I have learned my lesson in the past to ask why the batteries are discounted. I don’t want reconditioned batteries that have a short expected life, there is little value here. But if the battery is discounted due to a cosmetic defect then count me in. Who cares if it has a blemish in the case?

I have found it to be important to ask about a core charge since more often than not I am adding batteries and not replacing old ones therefore I generally do not have a core to trade in.  Some places charge more for cores than others

These days I always re-measure my battery location and estimate the overall size of my battery bank before I make my final decision as to which size battery to buy.  I learned my lesson one time thinking I could stuff 6 golf cart batteries down beside my generator only to find that when I included the battery boxes into the mix there was no where near enough room. I ended up with 4 batteries installed but would probably have achieved more capacity had I gone with 2-4D batteries in boxes. Oh Well. Another Boating Lessons Learned.

More information on battery selection and other 12 volt topics can be found in The 12-Volt Bible for Boats. This link will take you to Amazon where you can purchase the book. I have had a copy for years and every time I loan it out it seems to stay gone for a long time. Given I have had to replace it a few times I would say that it is a favorite among my boating friends. But that’s ok. It is a good source and I highly recommend you get a copy. If you buy it via the link I have provided it will cost you no more and I will receive a small percentage. Maybe over time I will earn enough to cover the cost of all those copies I have out on loan … LOL 🙂

OH. And thanks to all of you that have entered AMAZONthrough my blog and made purchases. It’s costs you no more to enter through my blog but when you do I receive a small percentage and it adds up. THANKS.

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