Westerbeke 4.5 kw drains its battery

[aeljizi]

Hello,

I have a 2002 Westerbeke Gas Genny with around 100 hours. I just purchased boat last season and it had only 60 hours on it. The issue I'm having is the generator runs fine but after about an hour it dies, and wont start back up due to dead battery.

I had battery tested and its good...11.8 volts while gen is not running but only 12.8 when its running. Just to be safe I've changed impeller, thermostat, fuel water separator, fuel filter.

I've tried to make adjustments to the electronic governor/battery charger.

2 questions:
when Genny is running with NO load what should my panel read in terms of AC from 0-150
when Genny is running with LOAD what should my panel read in terms of AC from 0-150
-typically ac, fridge, battery charger....

Any help would be greatly appreciated Thank you

 

[bahamabreisus]

11.8 volts is not a good battery, but that should not cause it to shut down. Westerbekes are very sensitive to oil level. Genny should be putting out about 120 volts under load or not.

 

[aeljizi]

ok, i will check oil level today. Do you know about "governor oil" or would this not apply to my genny. Thank you!

also wanted to add, it wont start up when it dies, but if i hook up jumper cables, it runs.?

 

[Boater420]

Welcome to CSR!

What model generator do you have? If you have a 4.5 gas genny I'm assuming your governor is mechanical and will require oil. Low oil in the governor will also cause a genny to shut down due to an over-speed condition.

My 4.5 BCG does not have an alternator. The only thing charging the battery is the boat's battery charger. If you have a battery only holding 11.8v, I'd replace it.

Adding the generator model to your signature will help others diagnose your problem easier. Here is a link to Westerbeke's Gas Generator page. Once you have your model number, download your documents so you'll have a reference guide.

https://westerbeke.com/carburetedgasolinegenerators.htm

 

[aeljizi]

Model number I'm not exactly sure. 4.2 bcg i believe. I have the serial number - 365456-e207
Thanks for the suggestion, I will add into my title.

 

[Boater420]

If you have a 4.2 BCG it has an electrical governor. No oil to worry about. The other three conditions that will shut down that generator is — high coolant temperature, low oil pressure, high exhaust temperature.

On Page 18 of Operator's Manual for your generator 4.2 BCG

The generator supplies a continuous 17 amp charge from its battery charger to the starting battery. It's possible the battery charger isn't working and not charging the battery. Perhaps that's why when you apply the jumper cables it stays running.

I'd start by swapping out the genny's battery with one of the other batteries on the boat to test this theory. If the generator runs correctly, you know it's at least the battery.

Do the same tests as before with volt meter. According to the manual you should see 13.4 if the charger is working.

 

[aeljizi]

Thanks Boater420. It was the battery. Need to be fully charged. I bought and installed a NOCO charger which I can turn on once in a while to keep my battery 100%.

 

[Boater420]

Thanks Boater420. It was the battery. Need to be fully charged. I bought and installed a NOCO charger which I can turn on once in a while to keep my battery 100%.

Glad it worked out for you.

 

[Giopapy]

I own a 2002 310DA, does the genny have his own battery ? I tought it uses the boat batteries

 

[aeljizi]

I own a 2002 310DA, does the genny have his own battery ? I tought it uses the boat batteries

Should have a separate dedicated battery only for Genny that’s not tied into the house batteries.