28 TE Batteriy Recomendations

[Yearwood]

Boat partner called today and it looks as if the batteries will no longer hold a charge. This is the second set we have had in a 2001 TE. First set replaced after 7 years for we felt that we were tempting fate. This set did not last as long. Questions:
1. Anyone have recommendation for a good type and make of battery. Originals were Trojan and not sure what the current replacements are.
2. What rating batteries are recommended. Main engine is a 300 HP Yanmar.
3. One problem is that we have always been running with both batteries on. My feeling has been to start with both on but then isolate them. In this latter case what position is the battery transfer switch in 1 or 2?

Many thanks.

[RobS]

There are some variables, for example: Do you spend time on the hook and need the most available "house" power? Do you plan to pull the batteries for the off-season?

There are many many types (lead-acid, flooded, AGM) and sizes. There is no real "right" setup, it's what works for you. Do some google searches and reading.

As far as question #3, you have to see how the selector switch is wired, one battery will be your start or engine battery and the other is house. I do not think starting and running on both is bad, but you should isolate to the house once you're shut down.

[jcollins]

I agree with Rob. If you search around you will find many discussions on the "best" battery setup. I have tried many brands, types, etc. over the years with this boat and prior boats. I am happiest with the Odyssey group 31. I purchased one in 2006 and two more in 2007. I use one for house and two for starting. I run and start with my selector in the "all" position. When on the hook I'll switch to position 1 (house) so my starting batteries stay fresh. I'll be happy with 7 years. I got mine at batterymart.com.

[Nancy]

John,

Why do you have two starting batteries? With three batteries, I would have expected the opposite: 2 house, 1 starting.

[jleonard]

A single group 31 will easily start a Cummins 6B. Should easily start a Yanmar also.
I usually leave my battery switch to ALL.
With a Cummins I know you can change the battery switch while the enigne is running because the alternator is "load dump protected" and you won't fry the diodes.
Not sure if the Yanmar alternator is built that way.

[RobS]

I had a 5yr old grp 31 house at one time that started my Yanmar, the Yanmar's barely crank at all and fire right off. But if you're in a situation where you need to crank awhile to bleed off air or crank first to get oil flowing I am not sure how well she would hold up...

Not sure on the protection of the alternator either but the battery selector switch is designed that as long as you go from (1) to (ALL) to (2) without passing the (OFF) position the contactor connection is made before it's broke so no worries on alternator damage.

[Yearwood]

Is there a way to determine if the battery switch is designed to allow switching while the alternator is running?

[RobS]

Are you referring to switching between the 1, both, 2 positions or switching to off? Is your switch a Guest? I believe they are all make before break but switching to off requires the Alternator field disconnect feature. If you feel the need to test you can access the 3 posts on the back of the switch and check the continuity or measure voltage as you change between the 3 positions.

[jcollins]

John,

Why do you have two starting batteries? With three batteries, I would have expected the opposite: 2 house, 1 starting.

It will start with one battery but Peninsular recommends two batteries for starting.

[Yearwood]

Anyway to check is the alternator disconnect feature is installed? Where would it be installed at alternator or switch?

Thaanks

[DougSea]

It's at the switch. Here's a write up and diagram from BlueSea:

http://bluesea.com/viewresource/91

It's the two, much smaller, terminals.

[Russell]

Most of the battery selection switches are make before break now but an easy way to check is to turn on a cabin light that you can see while switching through the various selections. It should be off in the off position and never blink when moving the switch position through 1-both-2. Engine off during this test of course.

[Yearwood]

Thanks for all of the interesting and informative info.

Don Yearwood
Osprey 2001 Yanmar 300
Davidsonville, MD