Strange Battery/electrical problem hope you can help

T

Thallac

Well-Known Member
Joined
16 Jun 2013
Messages
81
Visit site
I am not sure if you will be able to help as I have a strange electrical fault.

The problem is that after running the engine for 30 minutes the starboard power goes off making my gps flicker off and my vhf say lo battery. I then switch over to the port battery bank and the power comes back on. Then back to starboard battery pack and the power works okay for another 30 minutes, then the same problem starts ago.

I thought it was the battery isolator being faulty so have changed this, but it still persists.

The engine starts okay.

I have not tested the battery or alternator as not sure how to. Not sure how it can be the alternator as the batteries do not seem falt

The set up I have is

Port one battery for port engine
Starboard two batteries for sb engine and boat electrics.


Any suggestions. Hope you can help
 
Thallac said:
The problem is that after running the engine for 30 minutes the starboard power goes off making my gps flicker off and my vhf say lo battery. I then switch over to the port battery bank and the power comes back on. Then back to starboard battery pack and the power works okay for another 30 minutes, then the same problem starts ago.

I thought it was the battery isolator being faulty so have changed this, but it still persists.

The engine starts okay.

I have not tested the battery or alternator as not sure how to. Not sure how it can be the alternator as the batteries do not seem falt

The set up I have is

Port one battery for port engine
Starboard two batteries for sb engine and boat electrics.


Any suggestions. Hope you can help
Click to expand...

Could be alternator fault, connection or component is getting hot during the 30 min running and develops fault cutting power. When you change over you remove load, allowing alternator to cool down and start working, you change back starting the cycle again.

Have you voltmeters for the engines, or check battery voltage when power is lost, if 12 / 13 volt you have a faulty alternator.

Either way voltages at both batteries in fault condition is needed.

Brian
 
If your port and stbd engines start up OK on their respective batteries - it suggests that your batteries and alternators are all OK. If your house electrics work OK when connected to the port battery, then that circuit is also OK. That leaves the connection of house electrics to the starboard battery (you say you have two - just connected in parallel?). I can't think of any circumstance where the house circuit voltage would just cut out except for a poor connection somewhere. Do you use a 1-2-both-off switch? These can look very imposing from the outside but are real rubbish inside - try checking that 12 V is available at the switch when the fault occurs.

Maybe, though, you have a VSR between the starboard start battery and the starboard house battery? In this case, you would need to check that the VSR was charging the house battery correctly and that the house battery was holding charge OK.

Best of luck!
 
Hi thanks for the reply. I am new to boating and finding out you have to work things out as it is hard to get a mechanic to your boat. Will there be more than one earth? Will there be be an earth for the batteries as well as the engine. Thanks tim
Wit
 
First off, it will take a bit of effort but, disconnect the batteries and swap over port to sbd and vice versa.
This will do two things, remake all the battery connections and see if the fault moves with the batteries (faulty battery), stays with the engine circuit (alternator, regulator etc) or goes away (bad connection).
The result will tell you which path to travel.
 
You must log in or register to reply here.

Other threads that may be of interest

N
Volvo Penta Alarm Module/Alternator Issues
Replies
1
Views
227
superheat6k
superheat6k
steved
Batteries......what would you do
Replies
3
Views
258
Refueler
Refueler

Share this page

Top