New Batteries, Seafarer 226

[Dublin]

I have been doing research on batteries for a Seafarer powered with a Yam 200 HP HPDI. The minimum battery requirements for this motor are 675.0 Marine Cranking Amps and 182 Minutes of Reserve Capacity (Owners Manuel). The Reserve Capacity is especially important in this particular motor.

Definition:
CCA vs. MCA: the two common power measurements are CCA (Cold Cranking Amps, the number of amps a battery can deliver for 30 seconds at 0°F while maintaining its voltage above 7.2 volts) and MCA (Marine Cranking Amps, similar but measured at 32°F instead of 0°F)

A minimum RC of 182 minutes is hard to find in any Group 24 battery, which is probably why you see so many Gradys (200 HPDI) equipped with the Deka Gp 27 or 31 or equivalent.

The Deka Gp 27 "starting" battery (27M6) has 840 CCA, 1050 MCA, and 182 RC, their "deep cycle" 27 (DC27) has 575 CCA, 705 CA, and 225 RC. And their GP 31 "deep cycle" (DC31DT) comes in at 650 CCA, 800 MCA, and 225 RC. I did not see a GP 31 "starting battery" in the Deka specs.

I can be convinced but at the moment I am not considering AGM technology because of the expense and with the type of boating that I do I will replace the batteries every 3-4 years anyway. After three years my confidence level begins to drop off, so I replace.

I am probably going to go with the Deka 27M6 on bank #1 (starting) and the DC31DT on bank 2 (house), providing there is enough space in the locker. If not the DC27 will be the #2.

Last piece of information; Deka makes the batteries for many marine battery retailers. For instance the West Marine (Marine Starting Battery, 1050MCA, Group 27) is the Deka 27M6, made in the same building, with a WM label. There are many familiar retailers that have this battery with their own label.

 

[seasick]

This is a single motor, two battery application? If so, I don't like mixing battery types since they have different electrical charging characteristics. This is an issue if and when BOTH switch setting is selected. As to whether you need starting types, deep cycle types or combos, depends on what your typical current drain factors are when the motors are not running. For example, if you run electronics with high draws like big stereos or the like, a deep cycle is a better option.
I personally use dual starting type batteries, don't run a lot of stuff when the motor is off ( plotter and sonar, and VHF radio) and don't have issues with insufficient charge to start the motor.. I get 6 to 7 years out of my batteries. I know when they need to be changed, one cold day, the motor doesn't crank well on one battery and I need to select BOTH. To a great extent, the weather at your location affects battery life. The hotter it is, the shorter the lifespan.
One final comment on AGMs. Some older motors won't charge AGMs correctly as is also the case with some battery maintainers. I don't know about the 200 HPDI, but I would ask Yamaha if I wanted to consider AGMs.

 

[Doc Stressor]

Deka markets the 27M6 as a dual purpose battery.

Deka 27M6

In my experience, they work fine as both starting and house batteries. My first set lasted 7 years before I replaced them just for security. The still passed a load test. I run my electronics continuously off of the house battery while fishing with the engine turned off, so the 27M6 hold up to fairly deep discharge cycles.

I really like those batteries for marine use. I only use true deep cycle batteries for my trolling motor.

I've had really bad luck with AGM batteries in my boats. The West Marine (Deka) deep cycles usually short out a cell just before the 18- month warranty runs out.

 

[Ky Grady]

I'm a single motor application on my 228 and I'm running Interstates for both my main batteries and my trolling batteries. The mains are on a switch and are Group 24 with 800CCA and 1000MCA. The trolls are Group 27's and are wired for 24 volt for my trolling motor. I keep a small pair of jumper cables onboard just incase so I'll always have power to start main motor.

When fishing and motor is off I've got two units running along with a VHF and the AM/FM, so far no issues with starting, if I did I'd go to "both" on switch and fire up.

 

[Doc Stressor]

So you aren't using deep cycles for your trolling motor? If you draw a starting battery down to 20% or less of its capacity a few times, it will be toast.

My skiff, which has a trolling motor, came with an Interstate starting battery connected to 50 lb thrust Minkotta that the previous owner installed. It quit after the 3rd time I drew it down.

In my experience, the best 12V deep cycle trolling motor batteries are Trojan SCS225s. I've used these in my RVs for years and have turned on several guides in my area to them. They last for many years of heavy use. Their construction holds up to the pounding they get when mounted in the bow of a flats skiff. The only reason I don't use them in my own skiff is that they need to have the water level checked frequently and I have an access problem. Hence the AGMs.

 

[Ky Grady]

Sorry, should of clarified,,,,yes, my Group 27's are deep cycle for my trolling motor.