Upgrading the Battery System


By Steven Bull

You generally don’t think about your battery systems while boating—until something goes wrong. Then the seemingly little system becomes is a major issue.

I’ve had my share of battery “fun” in the three seasons I’ve had my 38-foot cruiser. I’ve had to replace wonky wiring. I’ve dealt with a mish-mash of batteries both type and condition—neither of which I recommend—and I’ve had more than one outing with friends or family interrupted by being unable to fire up the engines after a day on the hook.

After the last “Ok everybody, could you step to that side so I can open this hatch and jump the batteries,” comment I made late last season I vowed that I would spend the winter sorting it out once and for all.

I knew I was going to have to replace at least four of the seven total batteries I had in a two-two system for each engine, one for the generator and two for the inverter. If I was going to do it, I wanted to do it well. I decided all of them had to go. Finally, I would have seven identical batteries in terms of type, brand and age.

So out came the flooded batteries, one of which needed to be topped up so regularly it became a weekly check, and the older AGM, or absorbed glass mat ones as well.

I did the research and found Odyssey Batteries out of the United States. They started on the industrial side of things and are still big in the world of city bus and fire truck batteries. What impressed me was finding out their batteries are on US Coast Guard vessels, not to mention used in military vehicles and planes.

If it’s good enough for them it’s good enough for me.

There was a bit of sticker shock. The cost is about two-and-a-half times what I could have replaced mine for with big box brands, but Odyssey claims the life of their batteries is three to four times longer. Instead of a few seasons, they should be good for about a decade in a colder climate. In this case, you get what you pay for and I am more than happy to pay if it works.

In speaking with Odyssey Battery’s Bruce Essig, he convinced me it was legit.

“We refer to this as a thin-plate, pure lead battery,” he said, tapping the red and black battery’s plastic casing. “We’re using highly purified lead, no alloys no additional materials. So that allows us to build a battery that is dual purpose, so this can be a great starting battery and a great deep cycle battery. Totally sealed, no gassing.”

With the Olympics in our rearview mirrors, but still top of mind, the best analogy is that this battery is both a 100-metre sprinter and a marathon runner. It has the power to spark your massive engines, but the deep-cycle abilities to also run the house systems all in one.

The plates are made of 99.99% pure lead (not alloy) and are super thin, meaning they can cram more plates, about 15% more, into the same footprint. Add to that, the tin-plated brass terminals and stainless steel hardware and you have a heavy battery. Very heavy! The old batteries I hauled out were about 50-60 lbs (22-27 kg) each. These new ones are just shy of 80 lbs (36 kg). Just keep in mind this should be a once-in-a-decade chore.

“This is a battery that can be stored on the boat in the winter,” Essig told me as my grin grew ear to ear. “It has a 24-month shelf life at room temperature so when you go into colder temperatures, anything below probably -10 to -15 degrees Celsius this battery goes to sleep, chemically.”

In other words: the colder the better.

In better words: I don’t have to lug the batteries off the boat until they need to be replaced eight to 10 years from now. Just make sure everything is turned off and the batteries have a full charge heading into winter. For good measure, it’s a good idea to disconnect the negative terminals to kill the circuit so there is no draw whatsoever.

Leaving the batteries in year round means you aren’t as constrained with where they are located. In my boat, the original location was by a side hatch in the cockpit floor for easy access. The Odyssey Extreme only needs to be kept charged and dry so I was able to space out the location for better weight distribution.

I put the two inverter batteries on the starboard side by the generator and four batteries for the two engines and one for the generator on the port-side since the wiring was already perfectly measured, the fuses were in place and the cables were already marine-grade.

It was less work to only worry about running cables to two batteries, but it was still work! That’s two batteries worth of marine-grade cable to cut, terminal ends to secure—borrowing a heavy-duty crimper is a game-changer in this regard—and to shrink tube it all to make sure any moisture stays out.

On my Sea Ray there is a runway of cables along the bulkhead that I was able to take advantage of to keep things tidy while reaching the inverter. A few zip ties were necessary to keep things secure, but otherwise it was straightforward.

Granted it’s only been one season of using them but so far I have completely forgotten about my battery system. I’ll take that as proof that they’re working as promised. I’m eager to see how well they hold their charge come spring but one thing is for sure: it won’t be nearly as exciting as not having to lug hundreds of pounds of batteries out of my boat this fall!


ODYSSEY Extreme Series Marine Dual Purpose Batteries


Pulse (5-second) Hot Cranking Amps (PHCA) 2150
Cold Cranking Amps (CCA) 1150
20Hr Nominal Capacity (Ah) 100
Reserve Capacity Minutes 205
Dimensions L x W x H (in) 13.00 X 6.80 X 9.41
Metric Dimensions L x W x H (mm) 330.2 X 172.7 x 239.0
Weight (lbs) 77.8
Weight (kg) 35.3


This article is featured in the Fall 2016 issue of Boats&Places.

Previous articleMoving Forward with Backup Technology
Next article1966 Chris-Craft Constellation
Steven Bull is an Associate Producer and Host of PowerBoat Television. He grew up boating on runabouts and PWCs on the lakes around Huntsville, while his wife grew up on cruisers. It only took months after getting married for Steve to adopt that lifestyle. Together, they purchased a Sea Ray 380 Sundancer they keep at the Toronto Islands. A graduate of the University of Windsor’s business school, Steve worked in the front office of OHL and CFL teams before moving to Europe and working as a Ski Guide in the French Alps. He returned to Canada get a Master of Arts in Journalism from Western University (formerly UWO). Steve’s broadcast experience ranges from the BBC World Service in England, to business reporter with NTV in Kenya, and from 2010-2014 as a multi-platform reporter and host with CBC News. In 2014, Steve combined his passion for boating with his skills as a broadcaster by joining Lifestyle Integrated where he contributes to Boats&Places Magazine, BoatTest.ca, BoaterNews.ca, and of course, PowerBoat Television.