High Voltage alarm

[Matt M]

Great day on the water! Boat just came back from service for the 100 hours service package, oil, plugs, fuel filter etc... I have 160 hours on the motors but let them do the service because of a no wake mode issue that I needed to be fixed. So today I experienced a new alarm "Voltage" both my voltage alarms (both engines) were at 16. + when the alarms went off. Battery was on a tender for 48 hours prior to today and was replaced last year. I felt I needed to turn things on to bring the voltage down.
After returning back to the dock after 2 hours listening to music I had no alarms. During clean up and engine flush out no issues or alarms.

What could be causing the high voltage?

Thanks,
Matt

 

[ripler]

Voltage regulator/rectifier.

 

[FSH 210 Sport]

Great day on the water! Boat just came back from service for the 100 hours service package, oil, plugs, fuel filter etc... I have 160 hours on the motors but let them do the service because of a no wake mode issue that I needed to be fixed. So today I experienced a new alarm "Voltage" both my voltage alarms (both engines) were at 16. + when the alarms went off. Battery was on a tender for 48 hours prior to today and was replaced last year. I felt I needed to turn things on to bring the voltage down.
After returning back to the dock after 2 hours listening to music I had no alarms. During clean up and engine flush out no issues or alarms.

What could be causing the high voltage?

Thanks,
Matt

So question……… did the high voltage alarm go away after you were on the water for a while? If so, what was the voltage reading on the connext screen?

When you got home and flushed the engines, what was the voltage then?

 

[Matt M]

So question……… did the high voltage alarm go away after you were on the water for a while? If so, what was the voltage reading on the connext screen?

When you got home and flushed the engines, what was the voltage then?

Answer to question one, yes the alarms went away after sitting for 2 hours. Question two, never bother to look since there was no alarms.

 

[tdonoughue]

Were the alarms while the engines were running or while they were off?

I have never heard of a battery even holding 16+ V. If running the regulator may have failed and provided too much voltage to the batteries (and could trigger the alarm). If the engines were off and you were still at 16+, then I am very confused. You said both engine alarms went off, so it is unlikely sensors on both engines failed at the same time in the same way. So that means you did have the circuits at 16+ V. But without a source to get them there, I don't know how you would do that. Unless while at the shop they messed up and put your batteries in series...

So, I would check that.

 

[FSH 210 Sport]

Were the alarms while the engines were running or while they were off?

I have never heard of a battery even holding 16+ V. If running the regulator may have failed and provided too much voltage to the batteries (and could trigger the alarm). If the engines were off and you were still at 16+, then I am very confused. You said both engine alarms went off, so it is unlikely sensors on both engines failed at the same time in the same way. So that means you did have the circuits at 16+ V. But without a source to get them there, I don't know how you would do that. Unless while at the shop they messed up and put your batteries in series...

So, I would check that.

I think it unlikely that both reg / rect on each engine failed at the same time.. possible but highly unlikely. Having said that, one reg/rect may have failed and that drove the voltage above 16 VDC. It is interesting that the high voltage alarm and or condition did not return after start up.

@Matt M we need a more thorough explanation of how this occurred. Did it happen as soon as you started the engines? If not how long after? Please put your boat on the hose and take voltage readings while each engine is running-separately.

 

[tdonoughue]

Fully agree, @FSH 210 Sport . The engines and regs are separate, but the electrical systems join at the battery. One bad reg could push the voltage to 16+ while running only. If he was still getting 16+V after the engines were off, it could not have come from the engines. The only way I know a 12V battery could put out 16+V is if it is in series with another battery. They will go up above 12, of course. But I have not seen 16...

But then again, I learn new things each day.

The batteries in series also could explain the condition not returning. After the batteries are drained down to 13V or so, it would take a while to recharge them up to 16+V again...

But I would also like to see the answers to your questions (after he confirms the correct wiring of the batteries). The hose and separate running is a very good idea.

 

[Matt M]

I think it unlikely that both reg / rect on each engine failed at the same time.. possible but highly unlikely. Having said that, one reg/rect may have failed and that drove the voltage above 16 VDC. It is interesting that the high voltage alarm and or condition did not return after start up.

@Matt M we need a more thorough explanation of how this occurred. Did it happen as soon as you started the engines? If not how long after? Please put your boat on the hose and take voltage readings while each engine is running-separately.

So, this only occurred first when were out about 20 minutes into a slow run nothing over 10 knots. I only have one battery. After hitting 3K RPM it stopped but the stbd engine alarmed every 5 minutes. After sitting for about two hours and restarted no more alarms. I never got an alarm during flush so I never bothered to look at the voltage again.

 

[FSH 210 Sport]

So, this only occurred first when were out about 20 minutes into a slow run nothing over 10 knots. I only have one battery. After hitting 3K RPM it stopped but the stbd engine alarmed every 5 minutes. After sitting for about two hours and restarted no more alarms. I never got an alarm during flush so I never bothered to look at the voltage again.

Okay…. The alarms can stay active for a while after the triggering event.

What do you mean when you say “but the sbd engine alarmed every five minutes” ?

I’d say you had a ghost in the machine.. because as you raise rpm’s the voltage should keep increasing up to roughly 3000 rpm’s. So if the regulator was a having a problem shunting the voltage to ground it should have gotten worse as the rpm’s were raised.

 

[tdonoughue]

Gremlins. Had to be. With only 1 battery, had to then come from the regulator. But it makes no sense to me that it would happen at low rpm and then stop at high rpm. Should have been the opposite.

Didn't change the name of the boat without making the appropriate gestures to Poseidon, did you?

Next time you go out, grab a multimeter to go with you. Would also love to get an actual reading at the battery (one with the engines on; one with them both off; one with each engine running)...