Battery Issues

[aweaver1030]

I have a 1999 Advance 247 with a 225 ox66

I will start by saying I have minimal knowledge about marine batteries and wiring on a boat. ( I thought a 12v battery was fully charged at 12 not 12.7)

I bought two new batteries charged both to 12.7 volts (checked with voltmeter)

Hooked them to the boat with the battery switch off still reading 12.7/ switch on reading 12.55

The meter on the dash reads 12.4

Took the boat out dash meter reads 12.4 came up on plane dash meter reads 12.2 and stays there entire trip used the tilt/trim a couple of times meter on dash reads 12.2 drops all the way to 11.8 when I tilt while on plane

Come back in turn the battery switch off now batteries read 12.48

Is this normal or should I be looking for a problem in the system?

(I can post a picture of the batteries and how they are wired later today)

 

[JJF]

I am not an expert, but that "sounds" fine to me. My guess is that the battery(ies) are partially discharging while the boat is in use.

 

[aweaver1030]

It would pull the batteries down that much in one trip you think? Again I have no idea

 

[Hookup1]

Your battery wiring diagram would be helpful. I have seen some GW's wired where the second battery is just a spare and not connected and reversed when the a/b switch is flipped.

I'm a little concerned that the engine isn't charging the battery while running. Make sure the engine is charging the battery

Batteries should be charged overnight. They take a while depending on how discharged they were. Around 13.1volts when charging and 12.7/12.8 when fully charged.

The engine should charge the battery it is connected to. Even at idle they produce some level of charging. 13.1 volts.

After running the boat the battery connected to the motor should be full charged.




To check your battery charger and engine charging system...

This is a basic system test that can be done with a voltmeter. A Harbor Freight voltmeter is good enough. Start here and others can help going forward.

At the dock turns all your electronics on and disconnect the boat from shore power.

Put a volt meter on the starting battery and check voltage. Should be somewhere around 12.8 volts.
Check house battery. Should be around 12.8 volts. This is normal fully charged battery voltage.

Start the motor up. Check starting battery voltage. Should be around 13.1 volts.
Check house battery. Should be around 13.1 volts. This is normal voltage while engine is charging batteries.

Turn the engine off and reconnect shore power. Turn charger on. Both batteries should be around 13.1 volts indicating the charger is working. If you don't get charger voltage check inline fuse from charger at battery if your charger has one - common problem - sometimes they melt fuse holder.

7 Function Digital Multimeter​

Amazing deals on this 7 Function Digital Multimeter at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

[aweaver1030]

I’ll try that thank you

 

[DennisG01]

Compare your dash volt meter to the reading directly at the battery (ies). The dash meter could simply be reading low -- old/salty wiring can make things even worse. This will at least help out so you know whether or not to trust the dash meter as-is or to know to always add "X" volts to it to get the proper reading.

 

[aweaver1030]

So I checked the voltage with the motor running and the battery switch in the "both" position (batteries are wired in series) voltage was 12.55 motor idling

The previous owner has everything wired to what he called the starting battery and nothing hooked up to the house battery. My thought on this is he knew the house battery was bad so he hooked everything to the starting battery just so it would seem like the boat was running and the electronics were working. I say this because the house battery had the red wire out of the battery switch hooked up and the black wire which should have been connected to the starting battery just hanging down not connected.

So being my motor is not charging the batteries where do I start now?
Stator?
Lighting coil?
Magneto?

I have heard these terms but do not know how to diagnose

 

[seasick]

In this single engine setup there is no house battery per se. There are two batteries that can be used individually or paralleled together ( BOTH switch setting).
The 'house' loads as folks call them are drawn from the same battery or batteries that are used for the engine starting and running.

I don't know what voltage meter you used at the helm but whatever it is, it is probably not a good presentation of the actual battery state (and voltage. Whatever it is, it is probably powered off of the accessory bus or fuse/breaker panel. In that case, the voltage at that panel will drop as loads are turned on. The trim pump is a decent load and I am not surprised at all that the voltage dropped like it did.

A test that wil tell you more about the battery state is to note the voltage at the dash with the minimal number things running. Basically just the motor ignition and perhaps the VHF radio. Start to power up other devices like the plotter and see how the voltage changes. You will learn over time what normal is.
Try starting the motor with the switch set to BATT 1. When the motor starts and is at normal idle speed, note the voltage. With a little throttle ( and not in gear) rev to about 1200-1500 revs and see what the voltage is. I would expect it to rise to at least 13.3 to 13.5 volts. If your battery is run down, you could see 14+ volts.
That is normal.

Many boaters will run on one battery only, leaving the other battery in reserve should the first battery run down. You can alternate what battery you run on for different trips.
I will do that but on the return trip, assuming it will be at least 20 to 30 minutes, will switch to BOTH to make sure both batteries get charged.
In summary, I think everything is OK

 

[dogdoc]

Not sure what you have on your boat, but you probably have something other than engines. Radio, VHF, GPS, Sounder, etc. If you do then you should have a house and start system. Your OX66 may have and auxiliary charge wire, you can look at the cable coming from the engine in the bilge and you would see 2 ring terminals if you do not and three if you do. The aux wire is slightly smaller than the other 2. That wire would charge the house battery. It is a simple set up with one engine and 2 bats. I would use a 1-2-both switch for the engine side so that you have all possible combinations to start and run. I would designate the start battery number 1 and run on it unless there is a problem. For the house a simple on-off is enough. That system is predicated on the ability to charge both batteries separately when running, ie you have the aux wire. The aux wire can be added fairly easy if you do not have one already.
A minor correction, I doubt you batteries are wired in series, that would be 24v. Series increases voltage, parallel increases capacity. You are parallel if anything.
Shore charging will be you next project if you have not done so already look for a good 2 bank 10-20 amp smart charger.
Good luck

 

[aweaver1030]

 

[aweaver1030]

I couldn‘t get to rotate without the file being too large

 

[aweaver1030]

The battery labeled 2 in the picture I was told is the starting battery and the 1 is the house battery

As the picture shows “2” has two smaller red wires going to the positive side. One is for the bilge pump the other my guess is for the dash Volt gauge.
On the negative side it has one labeled fuel pump and two other thicker black wires coming off it. Plus the wire that hooks into the negative on the “1”battery. Checked both fuses in the picture one was a 10 and the other a 7.5 both were good.

I went down and started the boat with the switch on 1 it started but not right away the voltage read 12.47 while idling I put the RPM to 1200-1500 no change. I switched to 2 and the motor fired right up voltage read 12.47 no change with RPM increase. I turned the switch to off the motor shut off.

I took the cowling off looked under the flywheel did not see any frayed wires or loose connections. Checked the fuses they were good as well.

 

[Fishtales]

I'd get a good DVM to start and only use one measuring device. Write conditions down and keep a log. The dash unit likely isn't very accurate and is an indicator at best. Best to take an open circuitt measurement (battery switch off). The bilge pumps will still be connected, but you would hear them if they run. Usually you see 13-13.2 VDC but it can be lower. Don't switch the battery switch off or on to Batt2 while running. May not be good for some motors. You have redundancy so don't worry too much. You will see some fluctuations due to load put on the batteries at different times. I think your probably overly concerned at this point. Get some data and see how things go.

 

[SkunkBoat]

Seasick and dogdoc made all good points that I would make.

I would ignore everything you were told by the PO and start from scratch to figure out what you have.
Don't worry about the voltage until you know how you are connected.
You will waste your time and get confused. Forget about the meter right now. You can't troubleshoot until you know what you have.

You are NOT in "series". You have two separate 12V batteries.
I do see that the battery you call #1 is a deep cycle 24DC and the battery with the #2 above it is a marine starting battery 24MS. Thats not good unless you re-configure the batteries and get an Aux Charging cable or an ACR (Automatic Charging Relay)
I see a brown wire on the Battery 2. That is probably going to a bilge pump. Maybe the PO added a forward pump or re-wired the aft pump?

Turn the switch around to see the connections. There is 1, 2 and COM (Common, sometimes called FEED)

In the GRADY original config;
There is no Start or House Battery. The switch selects the battery that is connected to the Motor and House. The other battery does nothing.
The wire to Batt 1 should go to 1, the wire to batt 2 should go to 2, the motor and "House" (wire to the red button breaker) should be on COM.
The other end of the "house" wire from the breaker goes to a terminal block/fuse panel under the dash.
There are fuseholders for autobilge pump and "memory power" on 1 and/or 2


The config that dogdoc talked about is not standard Grady. It configures 1 battery as START and 2nd battery as HOUSE. It is wired differently so that they both always charge.
I don't see that you have that. I would do that. Use the 24MS as a START battery in position 1 and the 24DC as the HOUSE battery in position 2.

Go on Blue Seas website and look at Mini Add-a-battery kit.

 

[aweaver1030]

Sounds good I’ll look at it tomorrow thanks for the help

 

[Hookup1]

So I checked the voltage with the motor running and the battery switch in the "both" position (batteries are wired in series) voltage was 12.55 motor idling

The previous owner has everything wired to what he called the starting battery and nothing hooked up to the house battery. My thought on this is he knew the house battery was bad so he hooked everything to the starting battery just so it would seem like the boat was running and the electronics were working. I say this because the house battery had the red wire out of the battery switch hooked up and the black wire which should have been connected to the starting battery just hanging down not connected.

So being my motor is not charging the batteries where do I start now?
Stator?
Lighting coil?
Magneto?

I have heard these terms but do not know how to diagnose

Don't panic yet. You need to slow down and get better information to decide what is happening.

Batteries are not wired in series. Series would give you 24 VDC. I can see from the photo the black ground wire between the two negative posts. The red positive wires go to the switch positions 1 and 2. In the "both" position the batteries are paralleled giving you 12 VDC with more current capacity.

There are several wires on the one battery that are not switched. Not sure if they are load or battery charger. I can't tell what is wired to the switch. The second battery looks to be independent of the other unless you put them in "both" position. Everything should be wired to the common of the switch. This would allow the load (starting and house) to be switched between batteries as needed. Figure out first what is happening.

First of all only use your voltmeter for voltage readings. Ignore gauges or chartplotter voltages - they may not be accurate.
Don't put the battery switch in "both" while troubleshooting. Use the switch to switch between battery 1 and battery 2 and check readings.

First thing I would recommend is to check the engine charging. Set the switch to 1, turn off the onboard battery charger or disconnect the boat from shore power. Check the voltage on the battery.Should be around 12.7/12.8 for a fully charged new condition battery. Start the engine and check the voltage on the battery again. Should come up to 13.1 or higher if batteries were fully charged. Push the button on the side of the throttle to take out of gear and raise engine RPM's. Check voltage again. Should be 13.1 or above.

Turn everything off and repeat above with battery switch set to 2.

Once we figure of if engines are charging the batteries we can go back and see if the on-board battery charger is working. It's similar to above. I did not see a battery charger connection to battery 2. Maybe it's a single bank charger wired to the switch. See if you can get a make/model for the charger.

SEASICK, DOCDOG and SKUNK BOAT all make valid points. There is an optimal configuration but you are not configured that way. This question comes up every week and we all help troubleshoot the situation.

Side note: Update you're profile - where are you located?

 

[dogdoc]

Whoa!! A thumbs up from Skunk Boat and got my gauges to read the senders, its been a good day!

 

[glacierbaze]