House Battery vs. Starboard battery

J

JLR

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Freedom 285
On my Freedom 285, I am having a low battery issue. My engine page on my Garmin plotter says it is the starboard battery and when using things like the tilt trim for the engines, that starboard battery gauge does drop. However, as best as I can tell, my house battery in my two battery setup is my port battery not my starboard battery. Is it possible the tilt trim relay for the motors is NOT on the house battery? I am a bit confused. Any help would be appreciated.
 
I'm not looking at your manual but every Grady I have ever seen used the stbd bank as the house and stbd start.
get your manual.
 
My manual says battery 1 is the house bank. However, the manual does not specify which battery of the two is battery number 1. So, is battery number 1 the starboard or port battery. Just as an aside, the battery switches are labeled port and starboard. But, for some odd reason, at least in my mind, the switch on the right is labeled port and the one on the left is labeled starboard. Pretty whacky.
 
There is a diagram in your manual.

Facing the Bow, starboard is the right side port os the left side

Facing the batteries and switches, port is on the right

Bank 1 is always starboard motor start and usually also the house


The trim of a motor is powered by the battery that starts it That is controlled by your switch settings

Usually set so 1 starts stbd and 2 starts port

How many batteries do you have? Usually with twin motors there are 3 or 4 batteries and two switches
 
I have only two batteries. The battery that is likely bad is the battery that drops when, on the throttles, I press the raise or lower all. That toggle is on the port handle.
 
The starboard "BATTERY SWITCH" is the house switch and selects whatever battery(s) is powering the house. Don't think of a battery being the house, just a switch.
 
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Easier solution....

Check for charging voltage (via both battery charger and engine running). If good, disconnect the cables at the batteries and load test each battery. Replace the bad one... and the other one unless it's recently replaced.
 
wspitler said:
The starboard "BATTERY SWITCH" is the house switch and selects whatever battery(s) is powering the house. Don't think of a battery being the house, just a switch.
Click to expand...
We don't have enough info yet. I need his boat's battery Diagram because things are not being described fully or correctly.

He has twin motors. that implies he has 2 switches. One switch for Stbd motor and one switch for Port Motor.
Usually the HOUSE is tied directly to the Stbd motor. It always follows the stbd switch position.
the "1" position chooses Bank1, position 2 chooses Bank2.
Usually there would be 2 parallel batteries in Bank1 because they are running the House from that bank. Usually there is 1 battery in Bank2

Is it possible Grady only put one battery in bank1. yes
Is it possible that Grady wired the House separately with its own battery? yes ...but I doubt it. I haven't seen that in 7 years on this forum.

It sounds like the Bank 1 is weak but IDK for sure that he is even connected to bank1.
The symptom he describes is a red herring. The trim switch is on the port control, yes. that has nothing to do with it.
The power for Trim for each motor comes from the battery that is connected to the motor via its switch.

You need to know the switch positions of both switches to troubleshoot.
I would put stbd on 1 and port on 2 (this is the normal operating position of the switches) and then use the tilt/trim on the cowl as a quick test.

If you reversed those positions the stbd motor and House would connect to bank2
 
2 batteries with 2 outboards? GW usually has one per engine. There are other items attached, but I've not seen a pure house battery on a GW, maybe on the larger ones?
 
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How old is the boat and more importantly, how old are the batteries?
 
Normal Grady configuration has the starboard battery switch connected to the house and the starboard engine. The port battery switch is connected only to the port engine and possibly generator. Of course that configuration could be changed, but not likely. I always think of a switch as powering a buss. Each switch can select any combination of batteries, but can only provide power to the buss that it is wired to. Given that description, it should be quite easy to determine whether you have a bad battery or batteries and as others have said, it’s simple to load test them, the tester only cost about $20.
 
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I mean... if the batteries are anything more than say 5-7 years old, or if you're unsure on the age of the batteries, I'd just replace both of them and call it a day. Of course that's just me, but if they're that age or older, imo they're living on borrowed time. Good luck.
 
Here is the update. I replaced the port battery. That was the battery that was dropping too low when I used the tilt trim switch. The battery was two years old. I do not know why my plotter showed it as the starboard battery but it did. What is confusing to me is the following. In the course of determining the bad battery, I had it disconnected. When I went to look at the voltages on my Garmin chartplotter with the port battery disconnected, the plotter did come on but it showed no display of voltage on either battery. So, it is clear that the plotter is connected to the house battery (starboard) but for some reason, the voltage display on the plotter only works when the port (bad) battery is connected. I am guessing that means that my NMEA network, or its data, is connected to the port battery.

So, on my test run after putting in the new battery, the new battery ran down to about 12.5 volts underway after two hours. However, when it when down to about 12.4 volts, it immediately sprang back to 13.6 volts. Does this mean that my rectifier on that port engine is wonky or perhaps just the sender for the voltages? Or, is this the way it is supposed to work? I do not know whether I have an ACR.

One last point, and not to be snarky but just to inform. I hold a 100 Ton Master Captains license. I have been boating for over 50 years. I do know the difference between port and starboard.

Any continued advice is much appreciated. Thank you.
 
The voltage was checked at the battery to determine which was bad.
 
JLR, If the new battery was dropping in voltage while underway, I would say that your problem is in your charging systems. The voltage should not need to drop to low values before the alternator wakes up. It should be putting out 13+ volts all the time. Even at idle on the muffs if you have it at home on a trailer, it should be putting out over 13V all the time. I'm curious about what you find so keep us updated.

On another note, don't get your nickers in a wad over SkunkBoat explaining Port and Starboard to you earlier. He doesn't know if you are a teenager just out of high school and rich daddy bought him a boat or you are the King of Siam. :) Skunk knows a lot of stuff and is a good sidekick to have.
 
No disrespect intended to Skunk. I am certain he knows a whole lot more than I do.
 
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