Battery for Genset

[cordale]

That is all the details...Marine max did all that work/troubleshooting in July. The update of the current situation is from yesterday.

[ImRich]

That is all the details...Marine max did all that work/troubleshooting in July. The update of the current situation is from yesterday.

So the problem is fixed, or the gen still dies when you try to start the engine? Now it sounds like the gen dies if you just turn on the ignition, and you don't even get to the point of starting the engine. This sounds worse that as previously described.

Don't try to start the gen with any load on it, so don't turn on the transfer or generator AC circuit breaker until it's running steady for a minute or two. After it's running, then turn on the generator and transfer breakers.

I would have thought that the marine tech would have checked your batteries with a load check.

My guess is that there's something else lurking in the gen that is voltage sensitive if you're still having a problem.

[cordale]

The gen will die when I simply turn the starboard engine start key to the ready position.

[ImRich]

The gen will die when I simply turn the starboard engine start key to the ready position.

There should barely be a slight, barely noticible voltage drop on your battery when simply turning on the ignition to an engine, maybe a 1 to 3 amp draw.

I'd say to call back the marine tech to look at the generator. There's something going on that is more than just a bad or weak battery IMHO. As he mentioned, perhaps one of the generator safety circuits are a bit too sensitive.

There could also be a bad ground, or corroded wires/connectors somewhere.

[Chris_in_Texas]

Yes something is very wrong electrically with this. The alternator on the genny should be able to supply enough current that a bad shorted cell in the battery might cause that problem, however you wouldn't be able to start the main engine if that was the case. I would also check the battery isolator as well. Those diodes could have failed in a bad state. I am thinking that maybe a grounding issue too. However it sounds like its getting worse over time now as well. Need a current meter on the battery side to see what exactly is happening with current draw.

It could be a corroded wire or even a chaffed wire as well rubbing on something and that is why its getting worse. It, the wire, could be laying on a hot side of something melting though the insulation. Not really sure.

I always had the genny running first and then always started the mains, and it never shut off on either of my boats. The genny shared a battery with one of the mains. Even when I had a dying battery where I had to parallel the mains to start, the genny would stay running and not shut off. Those gennys were both Kohlers, one a 5ECD (older) and the other a 5EKD (newer).

[gofast24]

Agree with Chris.
Probably asked and answered before but too busy to read all the way back to the OP post= If you start the gen set first and then start either one of the propulsion engines what happens? As previously indicated this is getting interesting.

[cordale]

Gofast - If I have the genset running and start my starboard engine (or even turn the key to the ready position) the genset dies.

[gofast24]

Gofast - If I have the genset running and start my starboard engine (or even turn the key to the ready position) the genset dies.

Thanks for the clarification. What happens if you start the port engine when the gen set is running? This is getting more interesting!

[cordale]

Great question...I'll have to get back to you on that one.

[gofast24]

Great question...I'll have to get back to you on that one.

interesting to know if the gen stops when you have it running and then try to start the port engine! Try it and let us know!

[cordale]

Gofast...can you PM me your email address?

I tried sending you an email through this site, but I don't think it worked.

[cordale]

Ok so more troubleshooting information today for those that have been following this thread.

Refresher:
1. Had my boat for 5 years, never serviced Genset other than yearly oil/filter change
2. Never had issues with the genset, except for occasionally I couldn't shut it off with the Cabin switch
3. Could start under full load, and while running could start either engine and genset would stay running
4. What was new for this season? Replaced all four batteries: 2 house, 1 for portside engine, 1 for starboard engine / genset
5. Had boat down at LOTO so had Marine Max service it - They initially changed the impeller and said everything was running ok
6. Read the earlier post in this thread for all the work they did

One Issue:
1. Fires right up with no load and will stay running. I let it warm up for 10 minutes and then placed a load on it and it wanted to die. But if I hold the on switch up it will stay running. After ~2 minutes I could let off this switch and it would stay running.
2. I started it the next day cold, with full load, had to hold on switch up for 3 minutes and it stayed running fine.
3. Once running it would run fine no issues for ~30 minutes then die on its own. Had to wait ~20 minutes before it would start again.

Other issue:
1. When genset is running, If I try to start EITHER engine, the genset shuts off.
2. I tried having my wife hold the genset on switch up while I started the engine and it still killed the genset

As I'm typing all of this, I'm wondering if some of this goes back to my battery change out, at least the genset dieing when engine(s) are started.
I attached the wiring diagrams, based on these, I have no idea how starting the port side engine could cause the genset to shut down.

I'm about out of troubleshooting ideas here.

Any ideas??

[Rpontual]

I am wondering if you have a bad ground connection that is tricking to generator voltage sensing electronics. If the circuit detects "under voltage" it could trigger a generator shutdown.

This seems unrelated to battery voltage and it should be. A discharged battery should not shutdown the generator as this is the time that one would need the generator!

[cordale]

One other thing I forgot to add...When I had both engines running, I was not able to get the generator to start, not even with no load.

[Chris_in_Texas]

The generator should have enough alternator capacity to power itself when running. This is typically why people don't realize that their car batteries are dead. Cars typically have enough alternator power to run all their own electronics and accessories. The battery "should" be there just to supply spikes or starting, otherwise everything should run from the alternator itself.

I think maybe a call into a generator shop might be in order here. There is for sure some sort of electrical gremlin running around. Its very possible that the genny's alternator has failed as well so its 100% dependent on the main engine battery to function correctly. Need to see if the genny is running is there current going back to the start battery? A DC clamp on meter would let you know this. This could possibly be how it wants to die when loads are put on it. There is excitation voltage that is needed for the generator and if that happens to drop as load is increased then that could cause it to stop. I would reach out to the manufacture and find a marine generator shop in your area and see if they can come out.


Ok so an edit... Here is the service manual for you...

https://www.westerbeke.com/technical manual/44518_rev1_4.5-9.6bcgtc-e_technical_man.pdf

It does show that there should be 17 amps of power to charge the battery as well when its running.

The other thing that I don't see is what are they using for battery / alternator isolation? Are they using battery isolator or are they using ACR's? What year / model of boat is this in?

[cordale]

Chris,
Not sure on your last question about the isolation.

Boat is a 2001 Commodore 2960

Genset:

Model - 4.5BCGTC-614
Eng. Ser No - 751601-E006
Gen. Ser No - .004084

[Chris_in_Texas]

Ok most likely then you have one of these somewhere, look on the forward firewall of the engine room:

http://www.promariner.com/en/02-70-2

Look at the marketing resources section and grab the pdf manual and do the testing in the last page to make sure its good. I don't recall how the generator is wired into the switches / isolator.

[gofast24]

My thoughts= when your wife holds the "start" switch" to on (or crank/start) that switch usually is overriding the "low oil pressure cut out" switch as you dont have oil pressure when first trying to start the gen set (same thing with a typical propulsion engines circuit) . Sounds like a low oil pressure switch or something in the gen set safety circuit it not seeing the engine oil pressure is up to normal and that is why holding the start/run switch on will let the gen start and run (and after running for a few minutes the gen control board finally sees sufficient oil pressure to keep it running) . Worse case, check the gen sets oil pressure by connecting a mechanical gage in place of the low oil pressure switch (or just disconnect the wire to it) before started and running, might be just low oil pressure, dirty oil filter, bad engine oil pressure relief valve (usually on the oil pump inside the engine) , defective oil pressure switch, etc.? But, non of these ideas correlate to your gen set shutting off when starting your Stbd engine??

[cordale]

Thanks for the tips/suggestions.

Boating in Central Illinois our season is coming to a halt, so I don't know that i'll be able to resolve this season and provide feedback.

I replaced the oil temp switch in April of 2017 because I kept blowing fuses on start and finally narrowed it down to a bad switch.

Part of Marine Max's feedback this go round was wrong fuse size, well perhaps it WAS the correct size.

Fun Fun...

[gofast24]

Thanks for the tips/suggestions.

Boating in Central Illinois our season is coming to a halt, so I don't know that i'll be able to resolve this season and provide feedback.

I replaced the oil temp switch in April of 2017 because I kept blowing fuses on start and finally narrowed it down to a bad switch.

Part of Marine Max's feedback this go round was wrong fuse size, well perhaps it WAS the correct size.

Fun Fun...

Bad oil PSI switches shouldnt blow fuses (Switches are either grounded or open circuit depending on the set points) ?
Last thought as to what I would do= Disconnect the battery starter cable going to the propulsion engine starter (stbd. or port?) from the battery terminal (not the starter motor!) that both starts that propulsion engine and the gen set (be careful to not let the disconnected starter cable removed from the battery from touching any metal ground surface) . Start and let the gen set run for a minute or two and then attempt to start the other engine ( the one that you didnt disconnect from the battery mentioned above). Then , What happens? I do know your season is coming to an end, I grew up in MKE and went through many winters with my boats out of the water! Hopefully you can do this test before pulling out for the winter?
Let us know!