Bow Thruster Charging Circuit

[annv]

Hi According to the diagram it is used as a jump start devise to beef up the starter battery (or in your case the bow thruster) and could flatten both battery's, you dont need it to run the bow thruster you do need a automotive battery not a leisure battery, and you will need a charge relay to charge the thruster battery from one or both of your alternators. if you fit a charge combiner  both alternators will recharge your battery's quicker. John

[Islander]

This device is a charge relay with a secondary option of a start boost in the spec given in the installation instructions. It is actually quite a sophisticated device not to be confused with the old fashioned charge relays or start assist relays which were no more than a 12v solenoid switch.

If it being fed from the alternator +ve out I don’t see why it shouldn’t work. It may have been the most convenient to make the connection.

Why not borrow the other engines start battery to do a test run of the thruster and see if the charging engine/alternator circuit will function. I notice from the spec sheet you posted the device won’t switch on until the charging voltage has exceeded 13v. I would look for a voltage of 14v to 14.4v from the alternator and that should switch it on. 
 

Colin 

[Knodty]

1 hour ago, annv said:

Hi According to the diagram it is used as a jump start devise to beef up the starter battery (or in your case the bow thruster) and could flatten both battery's, you dont need it to run the bow thruster you do need a automotive battery not a leisure battery, and you will need a charge relay to charge the thruster battery from one or both of your alternators. if you fit a charge combiner  both alternators will recharge your battery's quicker. John

It doesn’t have a leisure battery fitted to the thruster. 

 

9 minutes ago, Islander said:

This device is a charge relay with a secondary option of a start boost in the spec given in the installation instructions. It is actually quite a sophisticated device not to be confused with the old fashioned charge relays or start assist relays which were no more than a 12v solenoid switch.

If it being fed from the alternator +ve out I don’t see why it shouldn’t work. It may have been the most convenient to make the connection.

Why not borrow the other engines start battery to do a test run of the thruster and see if the charging engine/alternator circuit will function. I notice from the spec sheet you posted the device won’t switch on until the charging voltage has exceeded 13v. I would look for a voltage of 14v to 14.4v from the alternator and that should switch it on. 
 

Colin 

The alternator is putting out 13.8 volts and I have that going to the Black box terminal 1 but nothing out of terminal 2 going to the thruster battery

[Islander]

Ok. With that level of voltage the relay should energise in 4 seconds (see above) if you have a battery connected to terminal2 as well. You may find that the relay won’t energise if your thruster battery is not present.  
 

Colin 

[Knodty]

3 minutes ago, Islander said:

Ok. With that level of voltage the relay should energise in 4 seconds (see above) if you have a battery connected to terminal2 as well. You may find that the relay won’t energise if your thruster battery is not present.  
 

Colin 

No this is why i think it is wrong relay to have fitted as it is not being used as it was designed a starter assist and not a relay, to start the charging circuit. 

[Smoggy]

I think the start assist is just an extra function and shouldn't be required for this setup, the relay is just acting like a VSR with a delay built in.

[Islander]

Peter, the primary purpose of this device is to charge another battery in say a caravan or motor home. Secondary purpose is start assist I.e. working in the reverse direction. 
If you are not happy with this setup then I would look at a complete update and I would recommend Victron products. E.g. our Victron Centaur charger on The Green Lady is over 20 years old (fingers crossed) and still going strong. Please note we live aboard and batteries get more use than the recreational boater.

Without knowing your entire electrics layout, my guess is one engine has split charge for domestics and it’s start battery and the other engine just charged its own start battery with the the charge relay added when the bow thruster was fitted. If this is the case fitting a split diode to charge the bow thruster may be the easiest option.

Colin

[Islander]

Exactly Smoggy.

C

[Knodty]

6 hours ago, Islander said:

Peter, the primary purpose of this device is to charge another battery in say a caravan or motor home. Secondary purpose is start assist I.e. working in the reverse direction. 
If you are not happy with this setup then I would look at a complete update and I would recommend Victron products. E.g. our Victron Centaur charger on The Green Lady is over 20 years old (fingers crossed) and still going strong. Please note we live aboard and batteries get more use than the recreational boater.

Without knowing your entire electrics layout, my guess is one engine has split charge for domestics and it’s start battery and the other engine just charged its own start battery with the the charge relay added when the bow thruster was fitted. If this is the case fitting a split diode to charge the bow thruster may be the easiest option.

Colin

I think there is a diode fitted to the boat and I think you are correct with your guess at how it is wired.
Tbh I need to do a little more investigating as to how it is wired as most of the wiring disappears behind the triple battery boxes I have and it is a bit like a plate of spaghetti 🙄

The battery fitted that has been fitted to the Bow thruster is a leisure battery, so I understand that will have to be replaced. 
 

Thanks for all your comments Guys they have been very helpful, and a little confusing as well, as my knowledge of domestic systems on a boat is very limited. 
 
Thanks 

Peter

 

[annv]

Hi Peter have a look at Sterling Power Products web site,   i have used these for years with no problems they have a phone line for advice and offer same day repair/replacement if you get to there site (Droitwich) before 10am, i have always had problems in getting Victron repaired. They come from Holland. And diode's are not ideal relays are much better. John

[BroadAmbition]

I too have used Sterling, excellent customer advice and care 

Griff