Anybody using AGM battery with Yamaha OB's

Larry K · Posted: Thu Mar 12, 2009 10:32 pm Post subject:

Ok with all the talk of gel or AGMs being good where the battery is not vented I have a few questions.

First some info:

1. I have twin Hondas 40hp with lead acid starting batteries in the starboard lazaretto. (Only 1 year old)

2. I think I would like house batteries to take some of the load off the starting batteries

Questions:

1. Has anybody put lead acid batteries under the V-Bunk and then vented them? If so how?

2. Has anyone used gel or AGM batteries (for house batteries) under the V-Bunk with a separate charging system using shore power only? In as much the a Honda 40hp will not charge it.

Any thoughts, It's OK the to tell me I'm nuts, my wife dose it all the time.

Hunkydory · Posted: Thu Mar 12, 2009 11:00 pm Post subject:

Harvey, forgot to answer your question on why the charge coil went out. Was not due to switching between batteries while running. If I remember right that is apt to take out the alternator diodes. The charge coil has gone out twice on us once going through the Venn Passage into Prince Rupurt and the other coming off outer coast into Lisianski Straight. Both times I had switched the batteries together for more amperage to the house and at the same time had them connected to both motor alternators long before loss of coil. This wouldn't have been a problem except when they are connected in this manner the rpm between the motors needs to be constant. Am not a electrician so don't know exactly how this burns out the charge coil, but both times one burned out the batteries were connected in the manner described with me making many throttle adjustments and not being really careful on how the rpms were being matched due to concentrating on wave and visual conditions in Lisianski Inlet and extreme boat traffic in Venn Passage. Les at EQ Marine explained to me the above on what was causing the coil to go, but if I explained it here wrong its due to my memory of what Les said not what He said.

Jay

Hunkydory · Posted: Thu Mar 12, 2009 11:12 pm Post subject:

thataway · Posted: Fri Mar 13, 2009 11:49 pm Post subject:

To answer Larry K's question. Yes, I have both AGM and wet cells on the Tom Cat--there it is a bit easier because there are twin engines, Each engine has two charging circuits. I have the AMG on one of the charging circuits. the starting battery on the other. The second engine has the flooded lead acid house bank on one charging circuit--and the second start battery on the other.

I have run small outboards (15 and 25 hP--which have poorer regulation than the larger ones) with garden tractor size (U1) batteries for 3 to 4 years, starting the motor at least 3 to 4 times every day. (Dogs ashore). No damage to the
AGM battery.

In your case you could run the AGM's on one engine's charging circuit and I believe the engine start batteries on the other motor's charging circuit.

I also charge AGM's on my C Dory 25 using set voltages with a VSR. The AGM's and Wet cells are not normally connected, except when charging thru the VSR.

hardee · Posted: Sat Mar 21, 2009 1:27 pm Post subject: Group 29's are in

New Dual Purpose SLA Group 29's are in. Slightly bigger, and some heavier. Will see how this works for this time, and post an update here or there. The mechanics rotated them (I think via shoe horns and micro surgery techniques Mr. Green

into the forward section of the lazarette, long axis of the battery is now perpendicular to the long axis of the boat. More room in the laz, but harder access to the wiring. Will be watching the voltages on my hightech WalMart Cig lighter meter, (best boat options under $20) Wink

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